Article: 225030 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <4485eeaa$0$3704$ecde5a14@news.coretel.net> Message-ID: Date: Wed, 07 Jun 2006 03:30:30 GMT clfe wrote: > DUH - I KNOW THAT - I was just saying the tapping let the people at the > surface know there were 9 people down there. MORSE CODE - "could" have > relayed much more info if one of them knew it. REREAD my message....... How do you send a 'dash' by tapping on a pipe? You apparently could revolutionize prison communications by providing an answer to that simple question. -- 73, Cecil http://www.qsl.net/w5dxp Article: 225031 of rec.radio.amateur.antenna From: "Sal M. Onella" References: Subject: Re: sealing coax holes in outside wall Message-ID: Date: Tue, 6 Jun 2006 20:36:46 -0700 "Chris W" <1qazse4@cox.net> wrote in message news:fy7hg.52579$9c6.12825@dukeread11... > Can anyone tell me what the official name of the putty they use to seal > the holes you run your coax through so bugs don't crawl in the wall or > water doesn't get in? I like to get all my hardware type items from > mcmaster.com. I'm sure they have it, if I just know what it is called I > can find it on their website. I was thinking "electrician's putty" or similar -- what we used to call "monkey shit" in the Navy, but I couldn't get a good match on Google for those terms. While mulling this over, I remembered also Plumbers Putty. While generally not used for coax, I have used it under sinks and in the garage for sealing around pipe penetrations. What I have is light tan in color. It stays soft and flexible (but I don't know what sunlight does to it or whether it will take paint). It's cheap and available and might be just what you need. Article: 225032 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: FIGHT! FIGHT! FIGHT! References: <1149609129.041873.312040@g10g2000cwb.googlegroups.com> <23774-44862470-817@storefull-3257.bay.webtv.net> Message-ID: Date: Wed, 07 Jun 2006 03:38:07 GMT Richard Harrison wrote: > (mx) is a straight line. Every value of (b) produces a straight lline > parallel with lhe line y=mx when b=0. Factor (b) is merely the offset > value of the sloped line in the x direction. Why must superposition preserve 'b' (as someone has asserted?) -- 73, Cecil http://www.qsl.net/w5dxp Article: 225033 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <448624c0$0$6154$39cecf19@news.twtelecom.net> <448628bb$0$3693$ecde5a14@news.coretel.net> Message-ID: Date: Wed, 07 Jun 2006 03:41:05 GMT clfe wrote: > I'm not sure if you're referring to my post or someone else's who I didn't > see. In "my" example - I was saying if a MIC was broken and they knew code, > they could short out the tranmit pins - like making and breaking contact > such as a key would do - to broadcast a coded message. It "can" be done. Please tell us when, in human history, it has ever been done. -- 73, Cecil http://www.qsl.net/w5dxp Article: 225034 of rec.radio.amateur.antenna From: "Sal M. Onella" References: <1148272981_5573@sp6iad.superfeed.net> Subject: Re: Grounding a metal roof Message-ID: Date: Tue, 6 Jun 2006 20:54:08 -0700 "Steve N." wrote in message news:e64jaq$mml$1@avnika.corp.mot.com... < snip > > Do you know about the web site? > http://www.usncva.org/ > didn't see any recognizable names there. > > 73, Steve, K9DCI I remember the typewriter shop at the receiver building. First door on the right, inside the front door. I never worked there, but I often fetched a shelf spare for an operator. I know about the NCVA, but I've never been to the website. Going now. TKS 73 John KD6VKW Article: 225035 of rec.radio.amateur.antenna Message-ID: <4486538A.5070005@fuse.net> Date: Wed, 07 Jun 2006 00:18:18 -0400 From: jawod Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> Cecil Moore wrote: > clfe wrote: > >> Many of you may have heard of the Quecreek Mine incident in PA some >> time ago. A pipe was drilled down into the shaft. Those at the surface >> heard 9 taps on it, signifying there were 9 miners there. NOW - if any >> of those miners KNEW code, they could have gotten a message to the >> surface as to what conditions were exactly, the extent of injuries as >> best they could, etc. > > > Not by tapping. International Morse requires dashes as well > as taps (dots). There is a tap code used in prisons that will > accomplish communications under those circumstances. And since > more people have been in prison than hold an amateur radio > license, seems that it would make more sense to require knowing > the tap code than to require knowing International Morse code. I seem to remember that the original Morse code was all clicks. I think the telegraph lines were DC current to electromagnetic clicking "receivers". The dashes were sort of implied by the spacing of the clicks...not that it matters to the antenna group, I guess. The only thing good about the prison system of taps mentioned earlier in the group is that if you know the grid, you know the "code". Extremely inefficient, however. Long live di-dah Article: 225036 of rec.radio.amateur.antenna Message-ID: <4486549E.7000802@fuse.net> Date: Wed, 07 Jun 2006 00:22:54 -0400 From: jawod Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <448624c0$0$6154$39cecf19@news.twtelecom.net> <448628bb$0$3693$ecde5a14@news.coretel.net> Cecil Moore wrote: > > > Please tell us when, in human history, it has ever been done. Yes. It was an episode of the old Adam-12 TV series. Patrolman was injured in a crashed cruiser. Mic out. but he could click the mic button...the guy on the other end directed him to "click once if you hear me and twice if you don't" Classic television: you had to be there. Article: 225037 of rec.radio.amateur.antenna Subject: Re: FS: High Quality Coax Connectors & Adapters at very low prices From: Larry References: <%fihg.6120$rS6.5893@fed1read11> Message-ID: Date: Wed, 07 Jun 2006 00:24:01 -0400 The spam is getting worse! "AAA RF Products" wrote in news:%fihg.6120$rS6.5893@fed1read11: > Path: > be01!atl-c01.usenetserver.com!news.usenetserver.com!border1.nntp.dca.gi > ganews.com!nntp.giganews.com!nx01.iad01.newshosting.com!newshosting.com > !68.1.17.232.MISMATCH!peer01.cox.net!cox.net!p01!fed1read11.POSTED!53ab > 2750!not-for-mail From: "AAA RF Products" > Newsgroups: > misc.industry.electronics.marketplace,rec.boats.electronics,rec.radio.a > mateur.antenna,rec.radio.amateur.boatanchors Subject: FS: High Quality > Coax Connectors & Adapters at very low prices Lines: 4 > X-Priority: 3 > X-MSMail-Priority: Normal > X-Newsreader: Microsoft Outlook Express 6.00.2900.2869 > X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 > X-RFC2646: Format=Flowed; Original > Message-ID: <%fihg.6120$rS6.5893@fed1read11> > Date: Tue, 6 Jun 2006 09:42:39 -0700 > NNTP-Posting-Host: 64.58.167.76 > X-Complaints-To: abuse@cox.net > X-Trace: fed1read11 1149612155 64.58.167.76 (Tue, 06 Jun 2006 12:42:35 > EDT) NNTP-Posting-Date: Tue, 06 Jun 2006 12:42:35 EDT > Organization: Cox Communications > Xref: usenetserver.com misc.industry.electronics.marketplace:126894 > rec.boats.electronics:160705 rec.radio.amateur.antenna:326563 > rec.radio.amateur.boatanchors:215022 X-Received-Date: Tue, 06 Jun 2006 > 12:42:35 EDT (be01) > > Please email sales@aaarfproducts.com or call 949 481 3154 (San > Clemente, CA, USA) for a copy of our latest catalog. > > > Article: 225038 of rec.radio.amateur.antenna From: blair thompson Subject: End-fed wire question. Date: Tue, 06 Jun 2006 21:34:26 -0700 Message-ID: <0ukc82prneu4c8u1pdnpe132g06353kvk2@4ax.com> I have a 63 ft. end-fed wire antenna which I am using with an MFJ-949 versa tuner, and 4 counterpoises cut for 1/4 wave on 15,20, 30 and 40 meters. Far end not very high, about 25 feet up a tree, shot up there with a slingshot. Pretty thick foliage right now, but not a lot of the wire is showing and in the clear as the near end of the wire slopes down almost to ground level (townhome QTH). Bit of an underperformer, and I was wondering whether it would be worth my while to install a ground rod in order to ground the tuner, and whether that might improve matters a bit, Thanks for any information. Blair VA7NA Article: 225039 of rec.radio.amateur.antenna From: "kd5sak" References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <4485eeaa$0$3704$ecde5a14@news.coretel.net> Subject: Re: Give up CB for ham? Message-ID: Date: Wed, 07 Jun 2006 04:36:52 GMT "Cecil Moore" wrote in message news:qLrhg.39959$4L1.32138@newssvr11.news.prodigy.com... > clfe wrote: > How do you send a 'dash' by tapping on a pipe? You > apparently could revolutionize prison communications > by providing an answer to that simple question. > -- > 73, Cecil http://www.qsl.net/w5dxp How about a fast double tap on the pipe (or bar) to signify a "dash"? It's not an elegant solution, but could be made to work. Those guys are probably not gonna try for 30 characters per minute anyway. Harold KD5SAK Article: 225041 of rec.radio.amateur.antenna From: wood@itd.nrl.navy.mil (J. B. Wood) Subject: Re: H FIELD ANTENNAS? Date: Wed, 07 Jun 2006 07:43:44 -0400 Message-ID: References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <23774-4485E9C0-784@storefull-3257.bay.webtv.net> <128c1e6mscrqe09@corp.supernews.com> In article <128c1e6mscrqe09@corp.supernews.com>, Roy Lewallen wrote: > Yes. American antenna salesmen haven't yet gotten as sophisticated as > the British inventors and purveyors of the CFA. But they're learning. Be > patient -- perhaps someday they'll reach that level. > The CFA proponents weren't sophisticated at all. The "inventors" probably read half of chapter one of an undergraduate electromagnetics textbook but forgot to read/understand the rest. Another source of embarrassment was that one of the CFA backers was a university EE professor. Go figure. Extraordinary claims but no extraordinary proof. BTW, in case you're interested, the British/Egyptian inventors' U.S. patent number is 5155495. It's patented so it must work... 73s from N4GGO, John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil Naval Research Laboratory 4555 Overlook Avenue, SW Washington, DC 20375-5337 Article: 225042 of rec.radio.amateur.antenna From: "J. Mc Laughlin" Subject: Re: H FIELD ANTENNAS? Date: Wed, 7 Jun 2006 08:21:18 -0400 Message-ID: <128dh45bejvrd5d@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> Dear Tom: Your message may one of the most interesting and unexpected that I have read in a long time. Some comments follow. Please note my extreme reluctance to engage in anything but a calm exchange of experiences and opinions. I have no interest in provoking you. Your experience does not seem to agree with experience at remote, flat, treeless sites here in Michigan. Please note the qualifiers in the last sentence. Especially in the UP of Michigan, at certain times of the year, P-noise is the major factor in limiting radio use. P-noise is not found on an antenna imbedded in a clump of trees when an antenna out in the open (many wavelengths from the first antenna) has P-noise. The follow-on is that since most sites are urban or suburban, few radio amateurs will experience P-noise. P-noise is observed when there is no rain nor thunderstorms, but plenty of wind. This is suggestive of moving charge discharging into the antenna. Of course, one could define this action as being "corona." Of course, if one places enough charge on a piece of metal eventually there will be "corona." Many antennas have a conductive path to earth that makes such an accumulation of charge unlikely. There is no doubt that an antenna experiencing P-noise will radiate and thus noise will be received by nearby antennas. That is why successful receiving antennas here in the flatland are placed a long distance from metallic objects. Most people have never heard P-noise because their site precludes same. A paper published in August about 1961 (IEEE Vehicular Transactions) is one of the few references that has been published that deals with means for reducing P-noise. The article involved a fixed, not mobile, antenna. It appears that additional work has not been published that deals significantly with fixed antennas. (Lots of papers exist dealing with aircraft antennas.) Your #6 is interesting. Unfortunately, there is so much radiation from what else is on a tall building that it is difficult to sort out where excess noise is coming from. An antenna inside of a slightly conductive radome that is placed a long distance from anything that could radiate might be different. Your #7 is especially interesting. Our EMC group has on the drawing board just such experimentation. We will be on the lookout for "end effects." Your note is a valuable observation. Regards, Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: JCM@Power-Net.Net wrote in message news:1149675056.576658.92120@c74g2000cwc.googlegroups.com... > > Reg Edwards wrote: > > Precipitation static, eg., from highly charged raindrops and fine snow > > or fine sand, impinging on the antenna wire, just causes an increase > > in receiver white noise level. It can be reduced but not removed by > > using a very thickly insulated antenna wire, like the inner conductor > > of a coaxial cable complete with its polyethylene jacket. > > ---- > > Reg. > > I've never seen a case of precitation static occuring that way. > > In every single case I've seen, whether on tall buildings, tall towers, > or antenna hear earth, it has always been corona discharges from the > antenna or objects near the antenna. > > How do I know this? > > 1.) I had side by side "insulated" and "unisulated" Beverage antenna > wires that are otherwide identical except for being spaced a few dozen > feet apart, and the antebnna pointed towards my tall towers had precip > static and the others did not. Both were equal in noise despite the > fact they are hit by the same rain or dust. > > 2.) I have Yagis on towers that are identical, and the LOWER antenna > almost never has precipitation static despite the fact they are hit by > the same rain or dust. > > 3.) I've had dipoles at various heights, and the lower dipole always > has much less precipitation staic than the high dipole despite the fact > they get the same rain or dust. > > 4.) The period of the noise has nothing at all to do with the number of > droplets hitting the antenna. It increases in pitch as the charge > gradient between earth and clouds builds, then when lightning flashes > it immediatly stops without time delay. > > 5.) On tall buildings on dark nights in storms, we could actually hear > the same pitch noise as the repeaters rebroadcast, and walk to the > noise source and actually see the corona. > > 6.) Antennas in fiberglass radomes were no quieter than bare metal > dipoles on tall buildings. > > 7.) I even used an electrostatic sprayer to charge droplets and hit an > antenna, and could only simulate noise when the antenna element had a > sharp point and I got near the sharp point...at which time I could see > faint corona. > > 73 Tom > Article: 225043 of rec.radio.amateur.antenna From: "Ken Bessler" Subject: Quad feedpoint Message-ID: Date: Wed, 7 Jun 2006 08:44:55 -0500 I just built a 3el 6m quad. Should I put a choke or balun at the feedpoint? What type? -- 73's de Ken KG0WX - Kadiddlehopper #11808, Flying Pigs #-1055, Grid EM17io, FT-857D, AL-84, Elecraft XG2, 4SQRP Tenna Dipper, Heath GD-1B Article: 225044 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: H FIELD ANTENNAS? References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> Message-ID: Date: Wed, 07 Jun 2006 13:45:28 GMT w8ji@akorn.net wrote: > Reg Edwards wrote: >> Precipitation static, eg., from highly charged raindrops and fine snow >> or fine sand, impinging on the antenna wire, just causes an increase >> in receiver white noise level. It can be reduced but not removed by >> using a very thickly insulated antenna wire, like the inner conductor >> of a coaxial cable complete with its polyethylene jacket. > > I've never seen a case of precitation static occuring that way. I experienced that kind of static in Arizona with wind, extremely low humidity, and bare wire. I've never experienced it in East Texas. -- 73, Cecil http://www.qsl.net/w5dxp Article: 225045 of rec.radio.amateur.antenna Subject: Re: End-fed wire question. From: chuck Date: Wed, 07 Jun 2006 09:53:31 -0400 Message-ID: <1149687760_46747@sp6iad.superfeed.net> References: <0ukc82prneu4c8u1pdnpe132g06353kvk2@4ax.com> <_MqdnV8xku6s9BvZRVnyiw@bt.com> Reg Edwards wrote: > "blair thompson" wrote >> I have a 63 ft. end-fed wire antenna which I am using with an > MFJ-949 >> versa tuner, and 4 counterpoises cut for 1/4 wave on 15,20, 30 and > 40 >> meters. Far end not very high, about 25 feet up a tree, shot up > there >> with a slingshot. Pretty thick foliage right now, but not a lot of > the >> wire is showing and in the clear as the near end of the wire slopes >> down almost to ground level (townhome QTH). >> >> Bit of an underperformer, and I was wondering whether it would be >> worth my while to install a ground rod in order to ground the tuner, >> and whether that might improve matters a bit, >> > ================================= > Blair, > A single ground rod will be virtually useless - that is unless it can > be driven into salt sea water. > In which case, it will be practically perfect! Not much gray area for ground rods in this Zoroasterian space. ;-) Well, as far as ground rods are concerned, it would be practically perfect, but your antenna as is would still not be. > If the radials are elevated above ground, then some improvement may be > achieved by allowing them to rest at ground level. This will increase > the effective height of the antenna. > > Better still, shallow-bury them. > > Even better, add more radials. Extra radials, on or underground, need > not be very long and not of any particular length. The more there are > up to a dozen or so, the merrier. > If the antenna is roughly a half-wave on 40 meters, mostly horizontal, I doubt that more radials will help much. > Important - try to get the near end of the wire as high as you can in > the air. Get some vertical wire into it. Can the near end be taken up > the side of the house and suspended from a chimney, TV antenna or rain > gutter or something? This will definitely make a noticeable > improvement. > ---- > Reg. > > If you are seeking more low-angle radiation for DX, then this will help and you may see more benefit from additional radials. You might consider attaching the guy to the chimney, etc., and running the "vertical" wire from the tuner up and away from the house. You don't want that vertical wire running right alongside the chimney or TV antenna support. Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- Article: 225046 of rec.radio.amateur.antenna From: "Caveat Lector" References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <4485eeaa$0$3704$ecde5a14@news.coretel.net> Subject: Re: Caught Sending Morse (was Give up CB for ham?) Message-ID: <_PAhg.178634$bm6.159481@fed1read04> Date: Wed, 7 Jun 2006 06:49:47 -0700 During long boring meetings at an Aerospace company, my buddy and I would send Morse by pencil taps, sharp tap was a dit and a tap-scrape was a dah. Worked well until a new manager gave his fist talk assuring us nothing would change - we tapped out BS. After the meeting, the new manager asked my buddy and I to stay for a moment after the meeting, With a smile, he sed Hi guys -- I'm W#XYZ Real call sign disguised to protect the guilty (;-) -- CL -- I doubt, therefore I might be ! "kd5sak" wrote in message news:EJshg.40736$fb2.8847@newssvr27.news.prodigy.net... > > "Cecil Moore" wrote in message > news:qLrhg.39959$4L1.32138@newssvr11.news.prodigy.com... >> clfe wrote: >> How do you send a 'dash' by tapping on a pipe? You >> apparently could revolutionize prison communications >> by providing an answer to that simple question. >> -- >> 73, Cecil http://www.qsl.net/w5dxp > > How about a fast double tap on the pipe (or bar) to signify a "dash"? It's > not an elegant solution, but could be made to work. Those guys are > probably not gonna try for 30 characters per minute anyway. > > Harold > KD5SAK > Article: 225047 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <4486538A.5070005@fuse.net> Message-ID: Date: Wed, 07 Jun 2006 14:03:01 GMT jawod wrote: > I seem to remember that the original Morse code was all clicks. Wasn't there a strong click when the receiver circuit closed and a different weak click when the circuit opened? The length of time between those two types of clicks was either a dot or a dash? -- 73, Cecil http://www.qsl.net/w5dxp Article: 225049 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Quad feedpoint References: Message-ID: <8gBhg.18641$VE1.11065@newssvr14.news.prodigy.com> Date: Wed, 07 Jun 2006 14:19:48 GMT Ken Bessler wrote: > I just built a 3el 6m quad. Should I put a choke or balun > at the feedpoint? What type? A few turns of coax will do the trick for 6m. How about this solution from an earlier posting? | | | Driven | Element | +====================================coax braid +------------------------------------coax center conductor | | ==============================+===coax braid | spacing | +--------------------------------+ | 1/4WL wire (~4.7') | -- 73, Cecil http://www.qsl.net/w5dxp Article: 225050 of rec.radio.amateur.antenna From: "Caveat Lector" References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <4486538A.5070005@fuse.net> Subject: Re: Give up CB for ham? Message-ID: Date: Wed, 7 Jun 2006 07:33:24 -0700 The first Morse machines scribed the dots and dashes on a moving strip of paper. Operators of the day found that they could decode the sound of the scriber by ear, so the scribing machines were scrapped. http://www.maxmon.com/1880ad.htm -- CL -- I doubt, therefore I might be ! "Cecil Moore" wrote in message news:p0Bhg.18634$VE1.9119@newssvr14.news.prodigy.com... > jawod wrote: >> I seem to remember that the original Morse code was all clicks. > > Wasn't there a strong click when the receiver circuit > closed and a different weak click when the circuit > opened? The length of time between those two types of > clicks was either a dot or a dash? > -- > 73, Cecil http://www.qsl.net/w5dxp Article: 225051 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <128ccnil05e0744@corp.supernews.com> Subject: Re: H FIELD ANTENNAS? Message-ID: Date: Wed, 7 Jun 2006 11:26:55 -0400 "Roy Lewallen" wrote in message news:128ccnil05e0744@corp.supernews.com... > Yuri Blanarovich wrote: >> . . . >> Roy, 'splain to him about this 1/8 or so thing. He still dungetit. > > Tom understands it, but I see you don't quite have a handle on it yet. > > Roy Lewallen, W7EL So I "don't get it" because I (and others) see the difference in reality, when electrostatic shield suppresses the local interference. You explain behavior of E and H field in the vicinity of antenna but that does not apply to "W8JI shield is the antenna" and "current at both ends of the loading coil is always the same". I will stick to my reality handle, rather than joining scientwist's chorus. 73 Yuri, K3BU Article: 225052 of rec.radio.amateur.antenna From: Tron Subject: Re: H FIELD ANTENNAS? Date: Wed, 07 Jun 2006 15:27:28 -0000 Message-ID: <128ds3056onlhb4@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> Roy Lewallen wrote: > > Bill Ogden wrote: > > OK, let me display my ignorance once again. > > > > There are many construction articles about ferrite-core antennas for the low > > bands. (Not to mention all the ferrite-core antennas in AM receivers.) Are > > these not H-field antennas, to a large extent? > > Only very locally, and only to a limited extent. > > When a signal originates far from an antenna, the response to E and H > fields is in the ratio of about 377 ohms, the impedance of free space. > This is true for *all antennas*. In other words, all antennas have the > same relative E and H response to signals originating far away. > > Very close to a small loop antenna, response is greater to an H field > than E field. It does respond to both, however, as all antennas must. As > you get farther away from the antenna, the response to the H field > decreases in relation to the E field response. At around an eighth > wavelength distance from the antenna, the response to E and H fields are > about the same as for a distant source. Beyond about an eighth > wavelength, the response to the H field is actually *less* than the > response to an E field compared to a source at a great distance. The > ratio of E to H field responses then decreases to the distant value as > you get farther from the antenna. > > In summary, the antenna responds more strongly to the H field if the > source is within about an eighth of a wavelength from the antenna. > Beyond that, it actually responds more strongly to the E field relative > to the H field than a short dipole or many other antennas -- you could > more properly call it an "E-field antenna" in its response to signals > beyond about an eighth wavelength. The difference in relative E and H > field response among all antennas becomes negligible at great distances; > for antennas which are small in terms of wavelength, the difference > becomes negligible beyond about a wavelength. > > Now, suppose you could make a magic antenna which would respond only to > the H field of a signal originating at any distance from the antenna > (which is impossible). "A system for determining the modulation imposed on a curl-free magnetic vector potential field.": http://jnaudin.free.fr/html/tepvppl.htm Other 'magic' antennae: http://rugth30.phys.rug.nl/quantummechanics/ab.htm Robust OP AMP Realization Of Chua's Circuit: http://citeseer.ist.psu.edu/kennedy92robust.html > What advantage would it have over a real antenna? I read the main reason was less electrostatic interference but with less immunity to strong nearby stations. Does the magnetic field really have less noise than the E-field? Polarization is also an interesting component. > Remember that the E/H ratio of any signal originating very far away is > 377 ohms, regardless of what kind of antenna or source it came from. I seem to recall this had something to do with the speed of light not being infinite. > > Roy Lewallen, W7EL Article: 225053 of rec.radio.amateur.antenna From: "Bill Ogden" References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> Subject: Re: H FIELD ANTENNAS? Message-ID: Date: Wed, 7 Jun 2006 12:05:09 -0400 I understand that E and H fields are intrinsic parts of the same thing (for radio waves, etc), and I am not trying to separate them along the lines discussed by some list participants. I would think that the E and H ratio of 377 is a function of the SI units of measurement involved. It would seem that there is the same amount of energy (at different and selected instances) in the E and H waves, and different units of measurement could produce a ratio of 1:1 (or anything else, with appropriate units of measurement). To return to the ferrite rod antenna: Ignoring the directional null capability (which might be very useful in some real-world circumstances) is there any advantage to a small ferrite rod antenna over a short wire antenna (assuming perfect amplifiers, as needed, following the antennas and assuming 160m or 80m usage)? As mentioned earlier, there have been a number of construction articles over the years explaining how a ferrite rod antenna did wonderful things for 160/80 operation. I have wondered if these results are generally valid, or were the result of the authors' pride in their works, or happened because the directional null abilities solved a local problem. Bill - W2WO Article: 225054 of rec.radio.amateur.antenna From: Tron Subject: Re: H FIELD ANTENNAS? Date: Wed, 07 Jun 2006 15:45:43 -0000 Message-ID: <128dt579n3outf2@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> Cecil Moore wrote: > > w8ji@akorn.net wrote: > > Reg Edwards wrote: > >> Precipitation static, eg., from highly charged raindrops and fine snow > >> or fine sand, impinging on the antenna wire, just causes an increase > >> in receiver white noise level. It can be reduced but not removed by > >> using a very thickly insulated antenna wire, like the inner conductor > >> of a coaxial cable complete with its polyethylene jacket. > > > > I've never seen a case of precitation static occuring that way. > > I experienced that kind of static in Arizona with wind, extremely > low humidity, and bare wire. I've never experienced it in East > Texas. Isn't this the triboelectric effect? I read this was a big problem for certain newer wireless applications. Energized TV antennas always feel 'gritty' when I brush my fingers lightly across them. Why is that? I also get a very mild shock sometimes, but that gritty electric sandpaper friction is very strange. Also the indoor TV antenna collects dust and vaporized cooking oil like there's no tomorrow. Is this like a Tesla coil? > -- > 73, Cecil http://www.qsl.net/w5dxp Article: 225055 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: H FIELD ANTENNAS? References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> Message-ID: Date: Wed, 07 Jun 2006 15:52:47 GMT Bill Ogden wrote: > To return to the ferrite rod antenna: Ignoring the directional null > capability (which might be very useful in some real-world circumstances) is > there any advantage to a small ferrite rod antenna over a short wire antenna? For the 1980's CA 75m mobile antenna shootouts, a ferrite rod antenna was used for receiving because the local human bodies had much less of an effect upon it than, for instance, upon a hamstick antenna. I always assumed it was because a human body has more of an effect on the E-field than it does on the H-field. -- 73, Cecil http://www.qsl.net/w5dxp Article: 225056 of rec.radio.amateur.antenna From: "Mike Y" References: Subject: Re: sealing coax holes in outside wall Message-ID: Date: Wed, 7 Jun 2006 12:04:17 -0700 When I used to work for a power company, they used a 'tape' that was like a strip of rubber just under maybe 1/8" thick. When you pulled it off the roll, you had to remove a paper backing, then 'stretch' the tape to activate it. Then when it was wrapped around a connection, it would 'cure' into a solid mass. I think RS used to sell something similar, but have no idea what it would be called. You might try some industrial electrical supply houses. Mike Article: 225057 of rec.radio.amateur.antenna From: Roger Subject: Re: sealing coax holes in outside wall Message-ID: References: Date: Wed, 07 Jun 2006 12:19:09 -0400 On Tue, 6 Jun 2006 20:36:46 -0700, "Sal M. Onella" wrote: > >"Chris W" <1qazse4@cox.net> wrote in message >news:fy7hg.52579$9c6.12825@dukeread11... >> Can anyone tell me what the official name of the putty they use to seal >> the holes you run your coax through so bugs don't crawl in the wall or >> water doesn't get in? I like to get all my hardware type items from >> mcmaster.com. I'm sure they have it, if I just know what it is called I >> can find it on their website. > I use the "expandable foam" that comes in a can about the size of a spray paint can. There are two types. The yellow foam that expands and gets hard which also is sensitive to UV which will cause it to change color (darken). Don't use this around areas where the pressure of expansion can cause problems like sealing around a door. They also have a "soft/flexible" version that is white and costs a bit more. It's what I use to block the large conduit between the tower and basement. http://www.rogerhalstead.com/ham_files/cablebox.htm Shows the conduit at the tower and coming in the basement. I just squirted the stuff in. I wasn't worried about it being pretty, just effective. With care you can be a lot more artistic. <:-)) It's easy to apply and easy to remove when necessary. Bugs and critters appear to not like the stuff. I like it far better than the putty. The yellow foam is a tad over $3 USD a can while the white, flexible stuff is $4 or $5 a can. Both are usually available at Lowe's, Builder's Square, and hard ware stores. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com >I was thinking "electrician's putty" or similar -- what we used to call >"monkey shit" in the Navy, but I couldn't get a good match on Google for >those terms. While mulling this over, I remembered also Plumbers Putty. >While generally not used for coax, I have used it under sinks and in the >garage for sealing around pipe penetrations. What I have is light tan in >color. It stays soft and flexible (but I don't know what sunlight does to >it or whether it will take paint). It's cheap and available and might be >just what you need. > Article: 225058 of rec.radio.amateur.antenna From: "Steven R. Jones" Subject: How to model linear loading in shortened dipole of vertical using EZNEC? Message-ID: Date: Wed, 07 Jun 2006 13:25:44 -0400 I want to work out a design for a linear loaded off center fed vertical dipole for 75M (perhaps will work multiband as well?) using linear loading in an "S" configuration, i.e: feedpoint I-----------------------------------()-------------I I I I----------------------------------I I------------I I I -----------------------------------I I------------- Which per my reading should let me design a 75M vertical that is only 60% of the length of a conventional radiator. A recent article in QST showed the successful use of 450 ohm ladder line with interwoven 3rd wire as a conveient way to build this sort od linearly loaded design. In attempting to model this design in EZNEC, I do not seem to get the loading effect and shorter length of the radiators to achieve resonance, nor do I get the feedpoint impedance lowering that is described for this sort of loading. I was hoping that the OCFD design would allow direct feed through a choke balun without having to deal with impedance transformations. with either an excessively low center feed impedance (with loading) or the typical ~200 feedpoint impedance and 4:1 balun required with the OCFD design at about 1/3 distance from one end. Any thoughts or prior experience to share? Steve KQ4WB Article: 225059 of rec.radio.amateur.antenna From: "Ken Bessler" Subject: Yet another 6m 3el Quad question Message-ID: Date: Wed, 7 Jun 2006 12:22:22 -0500 My Quad is all built and I'm waiting or FedEx to deliver my rotor. I built the quad out of wood, with a 1-1/4" dia pine boom and 4' mast plus 1/4"x48" spruce dowels for spreaders. I used insulated 16g stranded wire for the elements. All the wood is either painted or treated with sealer. Problem is I just broke a spreader moving the antenna and I'm worried about how fragile the whole design is. Would the performance change much if I used 1/4" aluminum rods instead? Maybe I should just get some fiberglass resin and paint the spreaders with several coats? How about wrapping them in re-enforced boxers tape (the good stuff with fibers in the tape)? Thanks for the help, guys.... -- 73's de Ken KG0WX - Kadiddlehopper #11808, Flying Pigs #-1055, Grid EM17io, FT-857D, AL-84, Elecraft XG2, 4SQRP Tenna Dipper, Heath GD-1B Article: 225060 of rec.radio.amateur.antenna From: "Steven R. Jones" Subject: Re: How to model linear loading in shortened dipole of vertical using EZNEC? Message-ID: References: Date: Wed, 07 Jun 2006 13:30:43 -0400 sorry, the diagram came out mangled on the post. the idea is a derivative of the construction used in "The K4VX linear loaded dipole for 7 MHz" QST, July 2002, pages 40-42. Thanks Steve On Wed, 07 Jun 2006 13:25:44 -0400, Steven R. Jones wrote: > I want to work out a design for a linear loaded off center fed vertical > dipole for 75M (perhaps will work multiband as well?) using linear loading > in an "S" configuration, i.e: > feedpoint > I-----------------------------------()-------------I > I I > I----------------------------------I I------------I > I I > -----------------------------------I I------------- > > Which per my reading should let me design a 75M vertical that is only 60% > of the length of a conventional radiator. A recent article in QST showed > the successful use of 450 ohm ladder line with interwoven 3rd wire as a > conveient way to build this sort od linearly loaded design. In attempting > to model this design in EZNEC, I do not seem to get the loading effect and > shorter length of the radiators to achieve resonance, nor do I get the > feedpoint impedance lowering that is described for this sort of loading. > I was hoping that the OCFD design would allow direct feed through a choke > balun without having to deal with impedance transformations. with either > an excessively low center feed impedance (with loading) or the typical > ~200 feedpoint impedance and 4:1 balun required with the OCFD design at about 1/3 distance from > one end. > > Any thoughts or prior experience to share? > > Steve > KQ4WB Article: 225061 of rec.radio.amateur.antenna Subject: Re: Have any of you mailed this to your ARRL Division directors and SM's yet? From: Ed References: Message-ID: Date: 07 Jun 2006 17:59:49 GMT > No more automatic renewals. Individuals must retest and pass all elements > required for their license class. > > > The passing score for written exams needs to be raised to 85%. > > > Code elements should be 13 wpm for General, and 20 wpm for Extra. > > > Make the no-code Tech license one year non-renewable. You forgot one item.... abolish the VEC program and mandate that all candidates must test at an FCC Field Office. Also, it would be nice to abolish transistors and madate using only tubes, too! :^) Ed K7AAT Article: 225062 of rec.radio.amateur.antenna From: Michael Coslo Subject: Re: Have any of you mailed this to your ARRL Division directors and Date: Wed, 07 Jun 2006 15:03:27 -0400 Message-ID: References: Ed wrote: >> No more automatic renewals. Individuals must retest and pass all > elements >> required for their license class. >> >> >> The passing score for written exams needs to be raised to 85%. >> >> >> Code elements should be 13 wpm for General, and 20 wpm for Extra. >> >> >> Make the no-code Tech license one year non-renewable. > > > > You forgot one item.... abolish the VEC program and mandate that > all candidates must test at an FCC Field Office. > > > Also, it would be nice to abolish transistors and madate using only > tubes, too! :^) All licenses should be terminated, immediately, and future testing will be a minimum of 110 wpm Morse code in a language that the applicant does not know. All sent straight key. Written tests will be changed to essay type. The applicant must demonstrate mastery of all aspects of RF discipline at the PhD level. Since people can look up answers in a book as well as a test question pool, all work must be new and cutting edge. Any answer that can be found in a book will disqualify the applicant. Upon the successful defense of the applicant's thesis, a 20 year waiting period starts. The work done by the applicant in pursuit of his license must be demonstrated to have a lasting and profound effect upon the RF discipline and especially so on the Amateur radio community. There may only be 2 hams left, but just imagine how superior they can feel about themselves........ Article: 225063 of rec.radio.amateur.antenna From: Allodoxaphobia Subject: Re: Have any of you mailed this to your ARRL Division directors and SM's yet? Date: 7 Jun 2006 19:29:02 GMT Message-ID: References: On Wed, 07 Jun 2006 15:03:27 -0400, Michael Coslo wrote: > > <-BIG snip-> > > There may only be 2 hams left, but just imagine how superior they can > feel about themselves........ And, the rec.radio.amateur... ng's will still suffer from trolls and off-topic postings. Article: 225064 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: H FIELD ANTENNAS? Date: Wed, 07 Jun 2006 12:39:34 -0700 Message-ID: <128earr46e4i34e@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <128ccnil05e0744@corp.supernews.com> My reality, and Tom's, fits with the clear explanations in Johnson's _Antenna Engineering Handbook_ (successor to Jasik); King and Harrison's _Antennas and Waves_; King, Mimno, and Wing's _Transmission Lines, Antennas, and Wave Guides_; and undoubtedly others, since it comes from basic electromagnetic principles. I explained the nature of the E and H fields from a small loop antenna. This is the sum of the fields from each part of the loop. It is not representative of the field in the small region between the wire and shield of a "shielded" loop, as you seem to be trying to infer. If you'd spend a fraction of the time studying that you spend desperately trying to find something wrong with anything Tom says, you'd have a much better understanding of how antennas work. Roy Lewallen, W7EL Yuri Blanarovich wrote: > "Roy Lewallen" wrote in message > news:128ccnil05e0744@corp.supernews.com... >> Yuri Blanarovich wrote: >>> . . . >>> Roy, 'splain to him about this 1/8 or so thing. He still dungetit. >> Tom understands it, but I see you don't quite have a handle on it yet. >> >> Roy Lewallen, W7EL > > So I "don't get it" because I (and others) see the difference in reality, > when electrostatic shield suppresses the local interference. You explain > behavior of E and H field in the vicinity of antenna but that does not apply > to "W8JI shield is the antenna" and "current at both ends of the loading > coil is always the same". > > I will stick to my reality handle, rather than joining scientwist's chorus. > > 73 Yuri, K3BU > > Article: 225065 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: H FIELD ANTENNAS? Date: Wed, 07 Jun 2006 12:53:57 -0700 Message-ID: <128ebmplg6g9080@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> Bill Ogden wrote: > I understand that E and H fields are intrinsic parts of the same thing (for > radio waves, etc), and I am not trying to separate them along the lines > discussed by some list participants. > > I would think that the E and H ratio of 377 is a function of the SI units of > measurement involved. It would seem that there is the same amount of energy > (at different and selected instances) in the E and H waves, and different > units of measurement could produce a ratio of 1:1 (or anything else, with > appropriate units of measurement). Yes, that's correct. What I tried to do in my explanation was to relate the E/H ratio near a small loop with that of free space. That makes the units of measure immaterial. > To return to the ferrite rod antenna: Ignoring the directional null > capability (which might be very useful in some real-world circumstances) is > there any advantage to a small ferrite rod antenna over a short wire antenna > (assuming perfect amplifiers, as needed, following the antennas and assuming > 160m or 80m usage)? You get a greater effective aperture (aka "capture area", and directly related to "effective length") from the ferrite rod antenna for a given physical size. This results in a larger signal for a given impinging field strength. If you had perfect amplifiers, that would make no difference, but real amplifiers generate noise, so a larger signal results in a better signal/noise ratio when you're at the level where the amplifier noise dominates the system noise figure. But if the signal level is large enough so that atmospheric noise dominates, having a greater aperture doesn't present any advantage. > As mentioned earlier, there have been a number of construction articles over > the years explaining how a ferrite rod antenna did wonderful things for > 160/80 operation. I have wondered if these results are generally valid, or > were the result of the authors' pride in their works, or happened because > the directional null abilities solved a local problem. Anecdotal reports of "wonderful things" should always be highly suspect, and placebo effect high on the list of possible causes. It might be easier to get a good null with a ferrite rod antenna than with a casually built antenna of some other kind, and that would be a big potential advantage. When considering the value of anecdotal reports, consider the widely reported benefits of various kinds of speaker cable, and the staggering amount of money that's being extracted from the believers. Roy Lewallen, W7EL Article: 225066 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: End-fed wire question. Date: Wed, 07 Jun 2006 12:58:35 -0700 Message-ID: <128ebvef3u49he6@corp.supernews.com> References: <0ukc82prneu4c8u1pdnpe132g06353kvk2@4ax.com> <4486a95f@nntp.zianet.com> BKR wrote: > > End fed wires must always be used against an efficient ground system > consisting of a large number of radials or a tuned counterpoise for each > frequency. > > A single ground rod is normally fairly poor. It depends on the length of the wire. If it's near an odd number of quarter wavelengths long, the radiation resistance between the end and ground will be low, and a good ground system is necessary to get good efficiency. If it's significantly shorter than a quarter wavelength, the resistance is lower yet and a very good system is required. On the other hand, if it's close to an integral number of half wavelengths, the resistance will be high, and you can get by with a very poor ground system -- in many cases just a ground rod -- without sacrificing a significant amount of efficiency. That's the reason why a half wave antenna works so well on an HT. Roy Lewallen, W7EL Article: 225067 of rec.radio.amateur.antenna From: Roy Lewallen Subject: Re: H FIELD ANTENNAS? Date: Wed, 07 Jun 2006 13:21:22 -0700 Message-ID: <128eda58dva2n33@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <23774-4485E9C0-784@storefull-3257.bay.webtv.net> <128c1e6mscrqe09@corp.supernews.com> J. B. Wood wrote: > . . . It's patented so it must work... Yeah, like U.S. patent 6,025,810, "Hyper-Light-Speed Antenna" (http://tinyurl.com/h546u). Roy Lewallen, W7EL Article: 225068 of rec.radio.amateur.antenna From: "Brian Hill" References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> Subject: Re: I bought a large capacitance hat for my vertical, but the antenna still gets wet when it rains. Message-ID: Date: Wed, 7 Jun 2006 16:22:52 -0500 "John S." wrote in message news:1149714609.565540.160300@c74g2000cwc.googlegroups.com... > > New Ham wrote: >> Did I get ripped off? > > You might try a Stetson. > four or five X beaver John? BH Article: 225069 of rec.radio.amateur.antenna From: "Yuri Blanarovich" References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <128ccnil05e0744@corp.supernews.com> <128earr46e4i34e@corp.supernews.com> Subject: Re: H FIELD ANTENNAS? Message-ID: Date: Wed, 7 Jun 2006 18:30:50 -0400 "Roy Lewallen" wrote > > If you'd spend a fraction of the time studying that you spend desperately > trying to find something wrong with anything Tom says, you'd have a much > better understanding of how antennas work. > > Roy Lewallen, W7EL > Congratulations Roy, you have nove graduated from "W8JI school of personal mud slinging" when running out of arguments. How perceptive: " ...desperately....anything Tom says...." "Better understanding" - you mean swallowing fallacies you scientwists proclaim? I will stick with my understanding of how antennas work and I can measure, vs. your misapplied theories why it "can't be so". 73 Yuri, K3BU Article: 225070 of rec.radio.amateur.antenna From: "Gil" References: Subject: Re: Have any of you mailed this to your ARRL Division directors and SM's yet? Message-ID: Date: Wed, 7 Jun 2006 19:12:12 -0400 Ed wrote: >> No more automatic renewals. Individuals must retest and pass all >> elements required for their license class. >> >> >> The passing score for written exams needs to be raised to 85%. >> >> >> Code elements should be 13 wpm for General, and 20 wpm for Extra. >> >> >> Make the no-code Tech license one year non-renewable. > > > > You forgot one item.... abolish the VEC program and mandate that > all candidates must test at an FCC Field Office. > > > Also, it would be nice to abolish transistors and madate using only > tubes, too! :^) > > > > Ed K7AAT Tubes are for appliance operators...real hams use SPARK!!! Hmm, wonder what a spark-gap transmitter would do to a BPL Internet deployment. Might have to try... Article: 225071 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Re: sealing coax holes in outside wall References: Message-ID: Date: Wed, 07 Jun 2006 23:19:49 GMT Think it scotch #23 tape (and several other numbers . Home Depot and Lowes has the stuff (Not to be confused with "Coax Connector Sealant" Radio shack # 278-1645, which is also great for sealing connectors against the weather). Great for weatherproofing, but needs to be covered (it is ultravilot sensitive) But- NOT to use it to plug holes! Dux Seal (a.k.a. "Monkey Shit" is MUCH BETTER-- Jim NN7K Mike Y wrote: > When I used to work for a power company, they used a 'tape' that was > like a strip of rubber just under maybe 1/8" thick. When you pulled it off > the roll, you had to remove a paper backing, then 'stretch' the tape to > activate it. Then when it was wrapped around a connection, it would > 'cure' into a solid mass. > > I think RS used to sell something similar, but have no idea what it would > be called. > > You might try some industrial electrical supply houses. > > Mike > > Article: 225072 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Re: I bought a large capacitance hat for my vertical, but the antenna References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> Message-ID: Date: Wed, 07 Jun 2006 23:31:19 GMT Reminds me of the time (many years ago), when the new kid on the gang was ordered to "Wash the Dishes" (microwave ), on a 150 foot tower ! Kid decided it was time to quit! Had to tell him it was a JOKE, or get the WHOLE Gang in hot water !!! Jim NN7K Brian Hill wrote: > "John S." wrote in message > news:1149714609.565540.160300@c74g2000cwc.googlegroups.com... > >>New Ham wrote: >> >>>Did I get ripped off? >> >>You might try a Stetson. >> > > > four or five X beaver John? > > BH > > Article: 225073 of rec.radio.amateur.antenna Subject: Re: I bought a large capacitance hat for my vertical, but the antenna still gets wet when it rains. From: Dave Oldridge References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> Message-ID: Date: Wed, 07 Jun 2006 23:42:40 GMT Jim - NN7K wrote in news:blJhg.19147 $VE1.18282@newssvr14.news.prodigy.com: > Reminds me of the time (many years ago), when the > new kid on the gang was ordered to "Wash the > Dishes" (microwave ), on a 150 foot tower ! Kid > decided it was time to quit! Had to > tell him it was a JOKE, or get the WHOLE Gang > in hot water !!! Jim NN7K Yeah. When I was in the RCAF many years ago, a common thing was to ask a newbie to go to the tool crib for a bucket of propwash. -- Dave Oldridge+ ICQ 1800667 Article: 225074 of rec.radio.amateur.antenna Message-ID: <448765D1.5060004@fuse.net> Date: Wed, 07 Jun 2006 19:48:33 -0400 From: jawod Subject: Re: Have any of you mailed this to your ARRL Division directors and References: > > > You forgot one item.... abolish the VEC program and mandate that > all candidates must test at an FCC Field Office. > Hell, do it right. Transfer ham radio to the Food and Drug Administration where we know we all belong. Annual meat inpections mandatory. > > Also, it would be nice to abolish transistors and madate using only > tubes, too! :^) > > > > Ed K7AAT Article: 225075 of rec.radio.amateur.antenna Message-ID: <448767E7.4040009@fuse.net> Date: Wed, 07 Jun 2006 19:57:27 -0400 From: jawod Subject: Re: I bought a large capacitance hat for my vertical, but the antenna References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> John S. wrote: > New Ham wrote: > >>Did I get ripped off? > > > You might try a Stetson. > Try a Dunce Cap (low capacitance) attached to your screwdriver and manually adjust until your dip meter reads moron :) Article: 225076 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: I bought a large capacitance hat for my vertical, but the antenna Date: Wed, 07 Jun 2006 19:21:51 -0500 Message-ID: <128ercucqikj3b0@corp.supernews.com> References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> <1149724604.928282.248280@u72g2000cwu.googlegroups.com> John S. wrote: > Or looking for a left-handed crescent wrench and fetching a bucket of > prop wash. The problem with this joke is that the wrench exhists. Handedness in a wrench is determined by which thumb closes the jaws. Right thumb right hand wrench, left thumb left handed wrench. I have a left handed crescent type wrench. Where was it made? POLAND of course. Wrench available for inspection. Dave WD9BDZ > > > Jim - NN7K wrote: > >>Reminds me of the time (many years ago), when the >>new kid on the gang was ordered to "Wash the >>Dishes" (microwave ), on a 150 foot tower ! Kid >>decided it was time to quit! Had to >>tell him it was a JOKE, or get the WHOLE Gang >>in hot water !!! Jim NN7K >> >> >> >>Brian Hill wrote: >> >>>"John S." wrote in message >>>news:1149714609.565540.160300@c74g2000cwc.googlegroups.com... >>> >>> >>>>New Ham wrote: >>>> >>>> >>>>>Did I get ripped off? >>>> >>>>You might try a Stetson. >>>> >>> >>> >>>four or five X beaver John? >>> >>>BH >>> >>> > > Article: 225077 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: H FIELD ANTENNAS? References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> <128dh45bejvrd5d@corp.supernews.com> <1149721730.564878.262550@j55g2000cwa.googlegroups.com> Message-ID: Date: Thu, 08 Jun 2006 01:37:13 GMT w8ji@akorn.net wrote: > J. Mc Laughlin wrote: >> P-noise is observed when there is no rain nor thunderstorms, but plenty >> of wind. This is suggestive of moving charge discharging into the antenna. > > So how does it get there? How does it build up? Where is the spark arc > or sizzle? This is a well known phenomenon in Arizona. What else, besides charged dust particles, could cause arcing at coax connectors on a perfectly clear windy day? -- 73, Cecil http://www.qsl.net/w5dxp Article: 225078 of rec.radio.amateur.antenna From: "J. Mc Laughlin" Subject: Re: H FIELD ANTENNAS? Date: Wed, 7 Jun 2006 21:47:20 -0400 Message-ID: <128f0bfir75r9ec@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> <128dh45bejvrd5d@corp.supernews.com> <1149721730.564878.262550@j55g2000cwa.googlegroups.com> Dear Tom: It appears that two noise mechanisms exist. The two are P-noise and corona noise. A receiver will experience close to white noise in both cases. However, corona noise tends to be accompanied by sudden stops and starts and P-noise starts with a sequence of perceptibly time spaced pops that increase in rate. If there is corona off of the top of a structure then it is reasonable to expect the antennas most close to the corona will "hear" more noise than the antennas that are farther away (such as below). It is also to be expected that moving charged particles that are higher above the ground will carry more charge on the average than charged particles that are moving near the ground. Depending on the wind and gradient, I expect that there is a height below which few charged particles are found when higher above ground charged particles are common. In short: If one can see corona, it will be the dominate noise source. If the gradient with altitude is not sufficient for corona, and weather conditions are such that moving charged particles exist, then out in the open the higher antennas are expected to have more discharges from moving charged particles per second and more noise than experienced by lower antennas. I have offered an alternative explanation for why, absent corona, higher antennas might well experience more noise. Actual precipitation (rain, snow, hail) is not needed for P-noise. Moving dust particles can carry charge and become charged. The noise does follow the "pattern of the particle rate." However, as you understand from other work, when the rate becomes high enough compared to the bandwidth of the receiver the result is essentially indistinguishable from white noise. Even with a 400 Hz bandwidth, the onset of P-noise is unique and comprises a sequence of pops that either die away or increase in rate to produce prodigious amounts of noise. I have used a time blanking circuit - noise clipper - and find that it is effective at lower rates. Corona noise does not seem to have the same temporal characteristics. A moving charged particle is able to discharge into an insulated conductor with aplomb. It is the very-close-to-the-antenna sudden accelerations of charge that produce noise (radio waves). What has shown promise is the use of slightly conductive coverings. The theory is that the amplitude of the pop will be reduced because the rate of charge transfer will be slowed. UV resistant materials that are easy to apply and that are not expensive seem not to exist. Obviously, too much conductivity would be ineffective. Absent actual corona, a noise mechanism is contended that comprises the sudden transfer of some or all of the charge on a moving charged particle (that occurs naturally) into an antenna's structure, support or even into insulation around same. A near optimum, HF, DX, low-noise receiving antenna is a small, horizontal, unturned loop antenna with an amplifier that is mounted on a wood pole having no metal inserts. The pole is some 200 meters from any exposed metal. The coax that runs up the pole to the amplifier is encased in conductive, plastic conduit as is the loop's wire. This antenna has close to a null at the zenith and is omnidirectional in azimuth. It is contended that what I have observed is not in conflict with what you have observed with corona discharges. 73 Mac N8TT P.S. Some months ago you asked about V antennas for low HF or MF use involving a 300 foot tower. I found that an interesting topic and did some analysis, which I tried to sent to you. Unfortunately, the E-mail address did not work. My conclusion, was, as well as I am able to remember, the same as yours: at the low frequencies involved, the effort did not have a reasonable pay-back. -- J. Mc Laughlin; Michigan U.S.A. Home: JCM@Power-Net.Net wrote in message news:1149721730.564878.262550@j55g2000cwa.googlegroups.com... > J. Mc Laughlin wrote: > > > P-noise is not found on an antenna imbedded in a clump of trees when an > > antenna out in the open (many wavelengths from the first antenna) has > > P-noise. The follow-on is that since most sites are urban or suburban, few > > radio amateurs will experience P-noise. > > That does not disagree with anything I said. A lower antenna surrounded > by taller objects is not subject to the same high voltage gradient as > an antenna out in a flat clear field. > > > P-noise is observed when there is no rain nor thunderstorms, but plenty > > of wind. This is suggestive of moving charge discharging into the antenna. > > So how does it get there? How does it build up? Where is the spark arc > or sizzle? > > > Of course, one could define this action as being "corona." Of course, if > > one places enough charge on a piece of metal eventually there will be > > "corona." Many antennas have a conductive path to earth that makes such an > > accumulation of charge unlikely. > > The fact is grounded or ungrounded antennas all behave the very same > way. Ask anyone who has yagis on towers. It is a potential difference > between earth and the atmosphere around the antenna. It isn't the > antenna charging up so much differently than earth. It is the > difference in potential between the antenna and the space around the > antenna. > > Remember those old tall mast wooden sailing ships soaked with saltwater > and the fire off the yardarms at night? > > > Your #6 is interesting. Unfortunately, there is so much radiation from > > what else is on a tall building that it is difficult to sort out where > > excess noise is coming from. An antenna inside of a slightly conductive > > radome that is placed a long distance from anything that could radiate might > > be different. > > You can walk right up to the noise source, and even see the corona at > night. It's very easy to take a FSM with audio monitor or AM receiver > with S meter and walk the roof for strongest noise, and it will > generally take you right to the tallest sharpest object (grounded or > not) on the roof. > > The last place you want to be is the tallest antenna on the building. > Get high winds or inclement weather and you will be destined for > noise....grounded antenna or not. > > We serviced dozens of repeaters and a few STL or Remote links in the > 70's, it was a pattern that repeated. > > I have a suggestion. Go to a forum where there are many people with > antennas at various heights, like a contesting reflector. Ask people > who have similar or identical antennas at various heights on a single > tall tower what they observe during high winds, nasty weather, or rain. > The very same wind and the very same moisture is impacting all of the > antennas, but without fail they will tell you the lower antennas are > always much better and the taller antennas are the first to go. > > If the P-staic is actually coming from the particles or moisture in air > striking the antenna, and if the same basic sample of weather is at all > the antennas, why are the upper antennas affected more? > > If it is the conductor charging, why do plumber's delight antennas or > folded elements with grounded centers have the same noise as insulated > elements? > > If it is moisture or particles striking the antenna causing the > problem, why is an insulated antenna with a single sharp protrusion > just as noisey as a bare antenna? Why doesn't the noise follow the > pattern of the particle rate, and why does it occur (as you even seemed > to say) when there is no actual precipitation? > > Since I've always had towers taller than 100 feet, and since I've > worked on VHF and UHF systems that had to stay up during storms, I've > spent a lot of time looking at this. I've not found anything that > points to the antenna charging differently than earth or being struck > by charged particles. > > 73 Tom > Article: 225079 of rec.radio.amateur.antenna Date: Wed, 07 Jun 2006 21:51:58 -0500 From: Tom Ring Subject: Re: Have any of you mailed this to your ARRL Division directors and References: Message-ID: <448790cf$0$6154$39cecf19@news.twtelecom.net> yea right wrote: >>Code elements should be 13 wpm for General, and 20 wpm for Extra. >> > > > No Way! 35wpm for extra! > Come on, that sets the bar way too low. 100 wpm CW, and 45 baud RTTY. RTTY is the wave of the future, after all. And we add a new class called "Extra Extra Read All About It!" where you have to copy Hellschreiber and PSK31 and copy and whistle 1200 baud packet. tom K0TAR Article: 225080 of rec.radio.amateur.antenna From: Mike Burch Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4485f6e7$0$26775$88260bb3@free.teranews.com> Message-ID: <19Nhg.22056$No1.19537@attbi_s71> Date: Thu, 08 Jun 2006 03:51:25 GMT Thanks for stepping up to the plate and admitting it. You got some points for that. :-) LLOYD THE LARDASS LOSER DAVIES wrote: > I'm an inbred alabama hick and I hate CB. > > > Lloyd Davies N0VFP > Cow Cornholer > Nutsackkk Gobbler > Dumpster Dweller > in Athens, Alabama > > wrote in message > news:1149534276.955122.310050@i40g2000cwc.googlegroups.com... >> Alot of people are telling me that CB is just for inbred hicks and that >> I should replace the CB in my truck with a ham radio. What do you >> thjink? >> > > > Article: 225081 of rec.radio.amateur.antenna From: "J. Mc Laughlin" Subject: Re: H FIELD ANTENNAS? Date: Wed, 7 Jun 2006 23:57:10 -0400 Message-ID: <128f7uvfmnrlq36@corp.supernews.com> References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> <128dh45bejvrd5d@corp.supernews.com> <1149721730.564878.262550@j55g2000cwa.googlegroups.com> <128f0bfir75r9ec@corp.supernews.com> <1149737733.436349.216110@f6g2000cwb.googlegroups.com> Dear Tom: Thank you for your ideas and the reference. Let us leave it that we see things differently. Readers have the ability to learn from contrasting each of our viewpoints. I have always included my E-mail address in my communications. I must to bed - tomorrow is the last lab day of the semester and I anticipate many questions directed to the proximate final exams. 73, Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: JCM@Power-Net.Net wrote in message news:1149737733.436349.216110@f6g2000cwb.googlegroups.com... > J. Mc Laughlin wrote: > > > It appears that two noise mechanisms exist. The two are P-noise and > > corona noise. A receiver will experience close to white noise in both > > cases. However, corona noise tends to be accompanied by sudden stops and > > starts and P-noise starts with a sequence of perceptibly time spaced pops > > that increase in rate. > > Pops are caused by something charging and flashing over. All it takes > to eliminate pops is a leak resistance or a leak choke slow enough to > keep the antenna from charging. > > I've never heard the slow popping noise called P-static by anyone I > know, but that doesn't say some people don't call it that. > > I have dipole high in the air, and on a clear day with a fair breeze > they will knock someone right on their butt if the feeder is unhooked > and the antenna allowed to charge. It does that dust or no dust, > although nasty weather seems to greatly increase charge rate. > > It's easy to see why that happens. > > http://www.who.int/peh-emf/publications/3_EHC_232_Sources_and_Exposure.pdf > > There is a significant electric field as we increase height even in > fair weather. Even though that is a very high impedance field, it > doesn't take air movement to charge a high conductor that is > well-insulated. > > > I have offered an alternative explanation for why, absent corona, higher > > antennas might well experience more noise. > > True, but a height change of just a few meters on a building or tower > hundreds of meters tall makes a big difference as do sharp compared to > blunt points on an antenna. > > During a rainstorm, when most people complain about corona, droplets > from the very same sources are hitting lower and upper antennas. The > noise does NOT follow the pattern or rate of raindrops hitting the > antenna, and the upper antenna is always significantly noisier than the > lower antenna. > > > Actual precipitation (rain, snow, hail) is not needed for > P-noise. > > Of course not. It is a voltage gradient problem. > > > Moving dust particles can carry charge and become charged. The noise does > > follow the "pattern of the particle rate." > > I've never seen it do that. But I'll keep watching for it. > > > P.S. Some months ago you asked about V antennas for low HF or MF use > > involving a 300 foot tower. I found that an interesting topic and did some > > analysis, which I tried to sent to you. Unfortunately, the E-mail address > > did not work. > > That's because the email address listed by Google for me is a dead > address. If it was live, it would be useless with spam and virus. > > 73 Tom > Article: 225082 of rec.radio.amateur.antenna From: Roger Subject: Re: sealing coax holes in outside wall Message-ID: <82ff825hutrj9r42aked488a2faasvqahu@4ax.com> References: <1149734093.836818.227270@f6g2000cwb.googlegroups.com> Date: Thu, 08 Jun 2006 02:05:09 -0400 On 7 Jun 2006 19:34:53 -0700, "George" wrote: > >Chris W wrote: >> Can anyone tell me what the official name of the putty they use to seal >> the holes you run your coax through so bugs don't crawl in the wall or >> water doesn't get in? I like to get all my hardware type items from >> mcmaster.com. I'm sure they have it, if I just know what it is called I >> can find it on their website. >> >> >> >> -- >> Chris W >> KE5GIX >> > >George >WB3HUH SAYS: > >Try DOW Chemical's "Great Stuff ", a "Tripple Expanding Polyurethane >Foam Sealant I'm surprised to see Dow with such a product when it competes with Dow Corning's compounds which are sold under the DAP as well as Dow Corning names. >This comes in a paint spray size can and is applied withan attachable >tube. >It sticks to everything, as it goes in as a liquid then expands to fill >even large holes. >It firms up and seals tight. Cable companies around here use it. Even >works well on cinder block > The various forms of expandable foam are easier to use, and to me work far better than the putty and self vulcanizing tape. The Silastic RTVs (TM) work well, but may be a bear to get out. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com > > >> Gift Giving Made Easy >> Get the gifts you want & >> give the gifts they want >> One stop wish list for any gift, >> from anywhere, for any occasion! >> http://thewishzone.com Article: 225084 of rec.radio.amateur.antenna From: kretko Subject: impedance Date: Thu, 08 Jun 2006 08:48:46 +0200 Message-ID: Hello ! Im looking for a formula impedance of conductor between two ground plane. _________ * h1 * p * h2 * _________ p -conductor h1 = h2 Thank you for your help ! Goodlack ! ! ! Article: 225085 of rec.radio.amateur.antenna From: John Ferrell Subject: Re: I bought a large capacitance hat for my vertical, but the antenna still gets wet when it rains. Message-ID: <077g82l0l7crfa52216an302bqf7icaiql@4ax.com> References: Date: Thu, 08 Jun 2006 12:56:49 GMT No. I know a fellow who works in Tech support for a big computer company who says they get questions likes this all the time. There are several reasons the product has failed to meet your expectations. 1- you have likely installed it upside down. 2- Your antenna is defective, the product is not meant to be used with a defective antenna. 3- Exposure to weather has nullified your warranty. 4- There is an improved replacement product available and you may wish to upgrade at a special price. de W8CCW John On Wed, 07 Jun 2006 20:26:26 GMT, cq-dx@arrl.net (New Ham) wrote: >Did I get ripped off? John Ferrell W8CCW Article: 225086 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: I bought a large capacitance hat for my vertical, but the antenna Date: Thu, 08 Jun 2006 08:45:40 -0500 Message-ID: <128gag4l6ir25e0@corp.supernews.com> References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> <1149724604.928282.248280@u72g2000cwu.googlegroups.com> <128ercucqikj3b0@corp.supernews.com> <1149773576.391521.292660@h76g2000cwa.googlegroups.com> John S. wrote: > > > David G. Nagel wrote: > >>John S. wrote: >> >>>Or looking for a left-handed crescent wrench and fetching a bucket of >>>prop wash. >> >>The problem with this joke is that the wrench exhists. Handedness in a >>wrench is determined by which thumb closes the jaws. Right thumb right >>hand wrench, left thumb left handed wrench. >> >>I have a left handed crescent type wrench. Where was it made? >>POLAND of course. >> >>Wrench available for inspection. >> > > > You had me going there for a moment..... > > I know...one side is labeled L and the flip side is labeled R. > No. This is an honest to god left handed crescent style wrench. Hold in left hand and close the jaws using the left thumb. Dave WD9BDZ Article: 225087 of rec.radio.amateur.antenna From: wood@itd.nrl.navy.mil (J. B. Wood) Subject: Re: measurements at the antenna Date: Thu, 08 Jun 2006 12:24:05 -0400 Message-ID: References: In article , dansawyeror wrote: > Good morning, > > This question is: Taking measurements at the antenna and what they mean? > > The antenna is a loaded vertical over a set of untuned radials. The feed is 50 > Ohm coax with a 1:1 isolation transformer at the antenna. I intend to run a > separate coax for measurement purposes to the feed point, stimulate the antenna > with a 10 mw signal at the operating frequency, and measure the voltage across > the antenna feed and the ground connection. > > Will the voltages indicate the relative RF impedance of antenna (including > loading coil) versus the ground? If the ground were near perfect the voltage at > the feedpoint should be close to zero. These voltages should indicate the power > disapation difference between the antenna and the ground. > > Thanks, > Dan Hello, Dan. If we have a quarter wavelength monopole the voltage at the feedpoint is at a minimum but definitely not zero even if we had a perfectly electrically conducting (PEC) ground. If we had a PEC ground and a monopole with no resistive (ohmic) losses then the impedance seen at the feedpoint at resonance would be about 37 ohms resistive. The 37 ohms is the radiation resistance of the antenna. This is where the RF power gets "dissipated" when that power is radiated into free space. If we use an electrically short antenna and put in say, a loading coil at the feedpoint to resonate the monopole at the desired frequency, we are looking at a radiation resistance of less than 37 ohms. It could be quite small depending on how short the antenna is. If in addition we have finite losses in the monopole structure, loading coil and in the ground/radials, we are measuring a resistance that is the sum of all ohmic losses and radiation resistance. And that's a classic problem - how to separate out all these losses. Without making radiation pattern measurements (to obtain total power radiated) about all you can do is calculate the radiation resistance for a PEC monopole fed against a PEC ground (or use an electromagnetics computation program like NEC to model the structure.). The measured value less the calculated radiation resistance would reflect the ohmic losses. And you still don't know how much of this is ground loss without knowledge of the other ohmic losses. There exits another direct measurement technique (Wheeler Cap) for determing antenna efficiency that can be readily applied to antennas in the GHz range but is not practical at HF because of the scaling factor (compare the size of 2.4 GHz yagi or log-periodic with the same type at 14 MHz to put things in perspective). Sincerely, John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil Naval Research Laboratory 4555 Overlook Avenue, SW Washington, DC 20375-5337 Article: 225088 of rec.radio.amateur.antenna From: Jim - NN7K Subject: Re: sealing coax holes in outside wall References: <1149734093.836818.227270@f6g2000cwb.googlegroups.com> <82ff825hutrj9r42aked488a2faasvqahu@4ax.com> Message-ID: Date: Thu, 08 Jun 2006 16:30:08 GMT Roger wrote: > > > The various forms of expandable foam are easier to use, and to me work > far better than the putty and self vulcanizing tape. The Silastic > RTVs (TM) work well, but may be a bear to get out. > > Roger Halstead (K8RI & ARRL life member) > (N833R, S# CD-2 Worlds oldest Debonair) > www.rogerhalstead.com Altho, these may be easier to use than dux seal, beware- if the stuff smells like Vinagar (as in Ascetic acid) , you may be contaminateing your coax, as is my understanding. And, MOST RTV's have this feature (contaminateing your coax)! Not a good situation! as info, Jim NN7K Article: 225089 of rec.radio.amateur.antenna From: gene@csl.uiuc.edu (Gene Gardner) Subject: Re: measurements at the antenna Date: Thu, 8 Jun 2006 18:28:06 +0000 (UTC) Message-ID: References: ...........some "seat-of-the-pants" observations (to use an old aviator expression): To judge the performances of two similar-sized mobile installations, note the value of the shunt-C required across the feed-coax to provide good SWR 50 ohm match (or shunt-L if that option is used). The more C required (less capacitive reactance), the better [or similarly, the less L (less inductive reactance), the better]. This method of match is actually a version of the classic "L-match" where the mobile whip with its loading coil represents either R in series with Inductance, OR R in series with Capacitance at the feedpoint....depending on whether the loading coil is tuned slightly Below, or Above the resonant frequency. The shunt C (or L) is the third element in the L-Match Equation. (Many readers will already know this) Since standard antenna equations calculate the actual radiation resistance to be very small in electrically- short mobile antennas, we know that with a perfect ground, and zero-loss mast and coil, the feed-point resistance would be only the radiation resistance of a few ohms, perhaps 2 to 5 (W8JI's web page calculates a 15 ft. antenna on 1.8 MHz to be only 1.22 ohms). Therefore, if the mobile feedpoint was found to have low SWR 50 ohm match with no shunt element, that would be very bad news........it would mean that perhaps 2 parts out of 50 were radiated, and the other 48 parts were loss! And of course, here no shunt C (or L) would be required which is the worst news. Conversely, back to "seat-of-the-pants thinking", the more C (or smaller L) required, the smaller the feed-point impedance had to have been....meaning less loss resistance included at the feedpoint. Article: 225090 of rec.radio.amateur.antenna From: "Jimmie D" References: <1149734093.836818.227270@f6g2000cwb.googlegroups.com> <82ff825hutrj9r42aked488a2faasvqahu@4ax.com> Subject: Re: sealing coax holes in outside wall Message-ID: Date: Thu, 8 Jun 2006 15:58:48 -0400 "Jim - NN7K" wrote in message news:kgYhg.42344$fb2.11559@newssvr27.news.prodigy.net... > > > Roger wrote: >> >> >> The various forms of expandable foam are easier to use, and to me work >> far better than the putty and self vulcanizing tape. The Silastic >> RTVs (TM) work well, but may be a bear to get out. Roger Halstead (K8RI >> & ARRL life member) >> (N833R, S# CD-2 Worlds oldest Debonair) >> www.rogerhalstead.com > > Altho, these may be easier to use than dux seal, beware- if the stuff > smells like Vinagar (as in > Ascetic acid) , you may be contaminateing your coax, as is my > understanding. And, MOST RTV's > have this feature (contaminateing your coax)! > Not a good situation! as info, Jim NN7K Not usually a problem when going through a wall unless the outer insulation is broken, but RTV is not may favorite for this. Plain old caulk works great unless you have a big void to fill. Article: 225091 of rec.radio.amateur.antenna From: Roger Subject: Re: sealing coax holes in outside wall Message-ID: References: <1149734093.836818.227270@f6g2000cwb.googlegroups.com> <82ff825hutrj9r42aked488a2faasvqahu@4ax.com> Date: Thu, 08 Jun 2006 17:13:19 -0400 On Thu, 08 Jun 2006 16:30:08 GMT, Jim - NN7K wrote: > > >Roger wrote: >> >> >> The various forms of expandable foam are easier to use, and to me work >> far better than the putty and self vulcanizing tape. The Silastic >> RTVs (TM) work well, but may be a bear to get out. >> >> Roger Halstead (K8RI & ARRL life member) >> (N833R, S# CD-2 Worlds oldest Debonair) >> www.rogerhalstead.com > >Altho, these may be easier to use than dux seal, >beware- if the stuff smells like Vinagar (as in >Ascetic acid) , you may be contaminateing your >coax, as is my understanding. And, MOST RTV's >have this feature (contaminateing your coax)! >Not a good situation! as info, Jim NN7K Jimmie already go this one, but if the seal is pretty much out in the open it will not contaminate the coax jacket. Normally the stuff won't bother the jacket any way, just don't apply directly to copper or aluminum braid as the Copper will turn green. OTOH there are versions available in Silicon that are non-contaminating and there are also latex/water based versions. Most of the DAP (TM) ( made by DC) is water based although you can specify Silicon. Once cured there is not a great deal of difference although there are some. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com Article: 225092 of rec.radio.amateur.antenna From: cq-dx@arrl.net (New Ham) Subject: Re: I bought a large capacitance hat for my vertical, but the antenna still gets wet when it rains. Message-ID: References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> <448767E7.4040009@fuse.net> <1149774341.518961.129650@i40g2000cwc.googlegroups.com> Date: Thu, 08 Jun 2006 21:18:31 GMT In article <1149774341.518961.129650@i40g2000cwc.googlegroups.com>, "John S." wrote: > >jawod wrote: >> John S. wrote: >> > New Ham wrote: >> > >> >>Did I get ripped off? >> > >> > >> > You might try a Stetson. >> > >> Try a Dunce Cap (low capacitance) attached to your screwdriver and >> manually adjust until your dip meter reads moron :) > >Uh oh...feeling a bit testy today??? What good's a hat if it don't keep the antenna dry? I think I'll keep it though, for some odd reason my SWR's are better. Article: 225093 of rec.radio.amateur.antenna Message-ID: <44889424.5070305@fuse.net> Date: Thu, 08 Jun 2006 17:18:28 -0400 From: jawod Subject: Re: I bought a large capacitance hat for my vertical, but the antenna References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> <448767E7.4040009@fuse.net> <1149774341.518961.129650@i40g2000cwc.googlegroups.com> John S. wrote: > jawod wrote: > >>John S. wrote: >> >>>New Ham wrote: >>> >>> >>>>Did I get ripped off? >>> >>> >>>You might try a Stetson. >>> >> >>Try a Dunce Cap (low capacitance) attached to your screwdriver and >>manually adjust until your dip meter reads moron :) > > > Uh oh...feeling a bit testy today??? > Not, not at all...didn't you see my :) ? No offense intended. Article: 225094 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: measurements at the antenna Message-ID: <3t4h82p7805tv1vqaq7hqcbturep8s49hc@4ax.com> References: Date: Thu, 08 Jun 2006 21:26:48 GMT On Thu, 08 Jun 2006 07:03:05 -0700, dansawyeror wrote: >Ohm coax with a 1:1 isolation transformer at the antenna. I intend to run a >separate coax for measurement purposes to the feed point, stimulate the antenna >with a 10 mw signal at the operating frequency, and measure the voltage across >the antenna feed and the ground connection. You seem to be implying more than one measurement, and that with those measurements you can separately determine (radiation resistance + loss resistance in the vertical and coil) and loss resistance in the ground system. Can you elaborate? Perhaps a block diagram of your measurement setup might reveal what you are thinking. (If you need a tool for drawing schematics in ascii text, Google for AACircuit. Alternatively, sketch it, scan it and publish it on a web site somewhere... DON'T attach it to your news post.) Owen -- Article: 225095 of rec.radio.amateur.antenna From: "W.Henry" Subject: 3 Killed in Fall From Iowa TV Tower Message-ID: Date: Thu, 08 Jun 2006 21:38:16 GMT 3 Killed in Fall From Iowa TV Tower Jun 01 http://www.breitbart.com/news/2006/06/01/D8HV79B00.html OAKLAND, Iowa Three workers fell 1,100 feet Wednesday from an Iowa Public Television tower and died, officials said. Bill Hayes, director for engineering at IPTV, said the crew was replacing strobe lights when the accident happened. "They were up fairly high when something went wrong and all three members of the crew fell," Hayes said. "We don't know what the actual cause was." He said a fourth member of the crew was working on the ground, operating a winch, hoisting parts to the crew. "We can only assume that the safety equipment failed," said Pottawattamie County Sheriff Jeff Danker. The men _ ages 57, 27 and 19 _ were pronounced dead at the scene. They worked for Deter Tower Service, of Grimes. Their names weren't immediately released. A woman answering the phone at Deters said no one was available to talk about the accident. She declined further comment. -- Humble to the humble , inflexible to the arrogant . begin 666 dot_clear.gif K1TE&.#EA`0`!`( ``/___P```"'Y! $`````+ `````!``$```("1 $`.P`` ` end Article: 225096 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: I bought a large capacitance hat for my vertical, but the antenna Date: Thu, 08 Jun 2006 16:46:03 -0500 Message-ID: <128h6krkcmme48c@corp.supernews.com> References: <1149714609.565540.160300@c74g2000cwc.googlegroups.com> <1149724604.928282.248280@u72g2000cwu.googlegroups.com> <128ercucqikj3b0@corp.supernews.com> <1149774179.543305.288650@f6g2000cwb.googlegroups.com> John S. wrote: > Brian Denley wrote: > >>David G. Nagel wrote: >> >>>John S. wrote: >>> >>>>Or looking for a left-handed crescent wrench and fetching a bucket of >>>>prop wash. >>> >>>The problem with this joke is that the wrench exhists. Handedness in a >>>wrench is determined by which thumb closes the jaws. Right thumb right >>>hand wrench, left thumb left handed wrench. >>> >>>I have a left handed crescent type wrench. Where was it made? >>>POLAND of course. >>> >>>Wrench available for inspection. >>> >>>Dave WD9BDZ >>> >>> >> >>At 23, I took a job as a young engineer at a place that had previously been >>a gyroscope manufacturer. As the new guy, they asked my to deliver a >>briefcase to the boss' office and (you guessed it) there was a spinning gryo >>in the briefcase. I got a big surprise when I tried to turn a corner in the >>corrider and the briefcase kept going straight ahead! A great 'new guy' >>trick. >>-- > > > > Or send the new guy in engineering to supply for a pressurized > container of Dihydrogen Monoxide. > Careful that stuff is extremely deadly if inhaled. > Or send the new finance guy to get the difference finder. > Article: 225097 of rec.radio.amateur.antenna From: "David G. Nagel" Subject: Re: I bought a large capacitance hat for my vertical, but the antenna Date: Thu, 08 Jun 2006 16:47:11 -0500 Message-ID: <128h6n0a56nj295@corp.supernews.com> References: <9LWhg.13749$523.13324@trnddc07> Reloader wrote: > John - KD5YI Wrote: > >>New Ham wrote: >>Did I get ripped off? >> >> >> >>Old Office supply joke. Goo get the paper stetcher. But I answered, >>you want the one in the maintenance shop or the one in Mr. Anderaon's >>(the owner's) Office. They VERY QUICKLY told me it was a joke. I told >>them, "I know." Hated me ever since. > > > Why do you hate yourself? Article: 225098 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Buyer Beware - Cobra Ultralight Message-ID: References: <1149770557.629987.141180@i40g2000cwc.googlegroups.com> Date: Thu, 08 Jun 2006 22:25:41 GMT On 8 Jun 2006 05:42:37 -0700, Mystery.DXer@yahoo.com wrote: >Buyer Beware Hmmm. >same antenna I purchased. I bought the Cobra junior antenna and >followed the directions for installation. The antenna is 50ft in the >air in a flat top configuration. When I hooked it up to my radio, it >would not tune on segments of certain bands, most noticeably 75/80. I >called Joe to get some help and was told that my radio, which has a >built in tuner would not accept more than a certain level of SWR and >was told to trim the twinlead back 19 feet. I did and while some of the >problem was solved, I continued to have problems on 75/80. I emailed >Joe to ask for further assistance and was told that the next step was >to buy a tuner extender (price $60). Not the answer I wanted to hear. >If in fact this kind of problem exists with radios that have built in >tuners, prospective buyers should know that in advance. For the cost of >the antenna and now the tuner extender, I could have bought a better >antenna, which is what I intend to do. I am not pleased with this >antenna and would not recommend it especially to someone who has a >radio with a built in tuner and intends to use it. Additionaly, the >performance on 40 seems to be very good. It seems to under perform on >20. Can't tell on 75/80 because I can't tune the band. That all seems pretty reasonable though the explanation that the "built in tuner would not accept more than a certain level of SWR" is not a good way to express the limits of internal tuners, but it is an explanation that would appeal to those with lesser knowledge. Well, it looks like you have learned something that many of us know, that the internal tuner in most radios has quite limited range and is really for minor trimming of loads to enable the radio to develop rated power (not to mention poor efficiency on the lowest bands). Joe advertises honestly that the antenna will need a tuner for operation on any frequency, perhaps he needs to spell out that what manufacturers fit into a corner of a transceiver may not be up to the task. Frankly, I am wondering why your beef isn't equally with the transceiver manufacturer for deceiving you with a tuner that isn't up to the task. I wonder what "better antenna" you have in mind? The short multiband HF antenna that has low SWR(50) on all bands (since you have an issue with tuners) and good performance is the holy grail of HF amateurs that will provide you with challenge for the years ahead. To some extent, the residual technical content in amateur radio is mating up system components that are compatible to form a working station. Owen -- Article: 225099 of rec.radio.amateur.antenna From: Bill Turner Subject: Re: Give up CB for ham? Date: Thu, 08 Jun 2006 15:43:18 -0700 Message-ID: References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> ORIGINAL MESSAGE: On Tue, 6 Jun 2006 09:36:21 -0400, "clfe" wrote: >I am of the opinion that a 5 WPM at least - should be kept on as a >requirement - as someday - it may be needed. Think not? Say you're in the >midst of an attack - of terrorism, a war on our homefront OR a large scale >natural disaster, a microphone isn't working or available. You can key the >radio but don't know code - now what? With code, even at 5 WPM - you could >get some very important information to those needing it to help save you - >to them. You could tell them WITH code, what is needed, exact whereabouts, >how many people involved, etc........ Just clicking a mic pin with a wire >won't tell anyone anything and could delay any help or a response big enough >to do much good. In these times with the large scale disasters as we've seen >and attacks - even for any said to be planned, NOW is a good time to WANT to >know code. IT may save you........ It is one of those skills you learn - >just like CPR or whatever - you hope you never have to use, but you're glad >you have it - when you need it. *********** REPLY SEPARATOR *********** Your priorities are skewed. Since there are only so many hours allotted to us, what would be a better way to spend your spare time: 1. Learning morse code for the above mike-failure scenario? 2. Stocking up food, water and ammo for the above mike-failure scenario? You have been reading too many stories of the valiant radio op on the Titanic. Ain't gonna happen. Bill, W6WRT 20 wpm Extra, but realistic about it Article: 225100 of rec.radio.amateur.antenna From: Bill Turner Subject: Re: Give up CB for ham? Date: Thu, 08 Jun 2006 15:45:28 -0700 Message-ID: References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <44858906$0$3702$ecde5a14@news.coretel.net> ORIGINAL MESSAGE: On Tue, 6 Jun 2006 09:54:14 -0400, "clfe" wrote: >One other thing........ I cut my teeth on CB back when the FCC was busting >CBers regularly for violations. I then got into Ham and Electronics. *********** REPLY SEPARATOR *********** Your CB origin is showing. "Ham" is an adjective, not a noun. One does not "get into ham", one "gets into ham radio". 10-4? Bill, W6WRT Article: 225101 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> Message-ID: Date: Thu, 08 Jun 2006 23:07:25 GMT Bill Turner wrote: > You have been reading too many stories of the valiant radio op on the > Titanic. Ain't gonna happen. Seems the bullies are not all on SSB after all. Didn't the Titanic's CW operator bully the California's CW operator to such an extent that he turned off, turned in, and the rest is history? -- 73, Cecil http://www.qsl.net/w5dxp Article: 225102 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <44858906$0$3702$ecde5a14@news.coretel.net> Message-ID: Date: Thu, 08 Jun 2006 23:08:38 GMT Bill Turner wrote: > "Ham" is an adjective, not a noun. Are you a ham? :-) -- 73, Cecil http://www.qsl.net/w5dxp Article: 225103 of rec.radio.amateur.antenna Message-ID: <4488B7B0.2000303@fuse.net> Date: Thu, 08 Jun 2006 19:50:08 -0400 From: jawod Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <44858906$0$3702$ecde5a14@news.coretel.net> > > Your CB origin is showing. "Ham" is an adjective, not a noun. One does > not "get into ham", one "gets into ham radio". > > 10-4? > > Bill, W6WRT > Gee, Bill. That's mighty specific. But since you brought it up. "Ham" can be used as a proper noun: "I'm a Ham". Not everyone goes to the trouble of saying "ham radio operator". It's also a sandwich. Article: 225104 of rec.radio.amateur.antenna Message-ID: <4488B859.1050108@fuse.net> Date: Thu, 08 Jun 2006 19:52:57 -0400 From: jawod Subject: Re: Have any of you mailed this to your ARRL Division directors and References: <6i2ig.3313$o4.2436@newsread2.news.pas.earthlink.net> > > I just knew none of you would take this serious and help. I bet you're > all democrats. > > sc Nope, Communist. Every damn one of us. Join us, comrade! Article: 225105 of rec.radio.amateur.antenna From: Owen Duffy Subject: Re: Buyer Beware - Cobra Ultralight Message-ID: References: <1149770557.629987.141180@i40g2000cwc.googlegroups.com> Date: Fri, 09 Jun 2006 00:59:53 GMT On Thu, 08 Jun 2006 20:33:12 -0400, Mike Coslo wrote: > I'd buy a tuner that will handle open wire feed, lose the 4:1 balun, >and get on the air. Mike, did you notice "Mystery's" comment re spending more money on a "tuner extender": "Not the answer I wanted to hear". She/he may be even less interested in the spend on the tuner you describe. I agree with you that antenna looks worth a try / perseverance, but it will probably need a wider range tuner than commonly fitted internal to transceivers unless you experiment (what's that!) to find a feedline length that the rig/runer accommodates on all bands, or switch feedline lengths. Owen -- Article: 225106 of rec.radio.amateur.antenna From: "clfe" References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> Subject: Re: Give up CB for ham? Date: Thu, 8 Jun 2006 21:29:02 -0400 Message-ID: <4488ced6$0$3683$ecde5a14@news.coretel.net> "Bill Turner" wrote in message news:co9h82d7fejjh7ac87n63pe9lgkcuu1120@4ax.com... > ORIGINAL MESSAGE: > > On Tue, 6 Jun 2006 09:36:21 -0400, "clfe" wrote: > > >>I am of the opinion that a 5 WPM at least - should be kept on as a >>requirement - as someday - it may be needed. Think not? Say you're in the >>midst of an attack - of terrorism, a war on our homefront OR a large scale >>natural disaster, a microphone isn't working or available. You can key the >>radio but don't know code - now what? With code, even at 5 WPM - you could >>get some very important information to those needing it to help save you - >>to them. You could tell them WITH code, what is needed, exact whereabouts, >>how many people involved, etc........ Just clicking a mic pin with a wire >>won't tell anyone anything and could delay any help or a response big >>enough >>to do much good. In these times with the large scale disasters as we've >>seen >>and attacks - even for any said to be planned, NOW is a good time to WANT >>to >>know code. IT may save you........ It is one of those skills you learn - >>just like CPR or whatever - you hope you never have to use, but you're >>glad >>you have it - when you need it. > > *********** REPLY SEPARATOR *********** > > Your priorities are skewed. Since there are only so many hours > allotted to us, what would be a better way to spend your spare time: > > 1. Learning morse code for the above mike-failure scenario? > 2. Stocking up food, water and ammo for the above mike-failure > scenario? > > You have been reading too many stories of the valiant radio op on the > Titanic. Ain't gonna happen. > > Bill, W6WRT > 20 wpm Extra, but realistic about it > > Not really, but I'm not in a mood to argue about stupid shit - anymore. Actually, I could care less. My ham days are few and far in between due to all the ass holes on there ruining it for the rest of us. Maybe you're right.......... the code really didn't keep the crud off the radios. Hell, why even have a test at all. Article: 225107 of rec.radio.amateur.antenna From: "clfe" References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <44858906$0$3702$ecde5a14@news.coretel.net> Subject: Re: Give up CB for ham? Date: Thu, 8 Jun 2006 21:30:17 -0400 Message-ID: <4488cf20$0$3686$ecde5a14@news.coretel.net> "Bill Turner" wrote in message news:i1ah82tjdddgjjvcsknsdnajpf5qmg40cs@4ax.com... > ORIGINAL MESSAGE: > > On Tue, 6 Jun 2006 09:54:14 -0400, "clfe" wrote: > > >>One other thing........ I cut my teeth on CB back when the FCC was busting >>CBers regularly for violations. I then got into Ham and Electronics. > > *********** REPLY SEPARATOR *********** > > Your CB origin is showing. "Ham" is an adjective, not a noun. One does > not "get into ham", one "gets into ham radio". > > 10-4? > > Bill, W6WRT > For christ's sakes - a misuse of words - so what........ I'm not an English Major. If that is all you can find to run off at the mouth about, why bother? Article: 225108 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: Buyer Beware - Cobra Ultralight References: <1149770557.629987.141180@i40g2000cwc.googlegroups.com> <1149817448.339895.295850@u72g2000cwu.googlegroups.com> Message-ID: <3G4ig.48095$Lm5.9297@newssvr12.news.prodigy.com> Date: Fri, 09 Jun 2006 02:03:43 GMT w8ji@akorn.net wrote: > The problem is that antenna is advertised to work all bands. > Unfortunately it doesn't do very well on many bands. Sounds like a G5RV. -- 73, Cecil http://www.qsl.net/w5dxp Article: 225109 of rec.radio.amateur.antenna From: dplatt@radagast.org (Dave Platt) Subject: Re: Buyer Beware - Cobra Ultralight Date: Fri, 09 Jun 2006 02:15:36 -0000 Message-ID: <128hme8sbfdeoe6@corp.supernews.com> References: <1149770557.629987.141180@i40g2000cwc.googlegroups.com> <1149817448.339895.295850@u72g2000cwu.googlegroups.com> >> >same antenna I purchased. I bought the Cobra junior antenna and >> >followed the directions for installation. The antenna is 50ft in the >> >air in a flat top configuration. When I hooked it up to my radio, it >> >would not tune on segments of certain bands, most noticeably 75/80. I > >> That all seems pretty reasonable though the explanation that the >> "built in tuner would not accept more than a certain level of SWR" is >> not a good way to express the limits of internal tuners, but it is an >> explanation that would appeal to those with lesser knowledge. > >The problem is that antenna is advertised to work all bands. >Unfortunately it doesn't do very well on many bands. > >The SWR is "off the scale" on many bands. The same would be true of almost any other doublet-style antenna, I think. Such antennas are often usable on a large number of bands if you have a wide-range transmatch/tuner, but I don't think I know of any which are usable in this way with the limited-matching-range "line flattener" ATUs built into modern solid-state transceivers. The Cobra Ultralight is only about 60% as long as a normal resonant near-half-wave dipole for 75/80 meters. It's shortened by linear loading. I imagine it has a narrower SWR bandwidth than a simple dipole. The manufacturer states that a tuner _is_ required. The wording is perhaps somewhat more optimistic about using a transceiver's built-in ATU than is justified, though. I wouldn't plan to use an antenna of this sort without a good external tuner with balanced-output capability (whether intrinsic or via a good current balun). The original poster might want to consider making a multi-wire (or "fan") dipole. With several sets of wires it'd surely be possible to make one which would tune on 80, 75, 40, and 20 well enough to not need an external tuner... although fitting it into under 80 feet of linear space might prove to be a challenge. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! Article: 225110 of rec.radio.amateur.antenna From: "Jerry" References: <1149770557.629987.141180@i40g2000cwc.googlegroups.com> Subject: Re: Buyer Beware - Cobra Ultralight Message-ID: Date: Thu, 8 Jun 2006 22:38:40 -0400 wrote in message news:1149770557.629987.141180@i40g2000cwc.googlegroups.com... > Buyer Beware > I have read all the reviews and I am wondering if they are about the > same antenna I purchased. I bought the Cobra junior antenna and > followed the directions for installation. The antenna is 50ft in the > air in a flat top configuration. When I hooked it up to my radio, it > would not tune on segments of certain bands, most noticeably 75/80. I > called Joe to get some help and was told that my radio, which has a > built in tuner would not accept more than a certain level of SWR and > was told to trim the twinlead back 19 feet. I did and while some of the > problem was solved, I continued to have problems on 75/80. I emailed > Joe to ask for further assistance and was told that the next step was > to buy a tuner extender (price $60). Not the answer I wanted to hear. > If in fact this kind of problem exists with radios that have built in > tuners, prospective buyers should know that in advance. For the cost of > the antenna and now the tuner extender, I could have bought a better > antenna, which is what I intend to do. I am not pleased with this > antenna and would not recommend it especially to someone who has a > radio with a built in tuner and intends to use it. Additionaly, the > performance on 40 seems to be very good. It seems to under perform on > 20. Can't tell on 75/80 because I can't tune the band. > > KC2GWK Lots could be wrong here including trying to kibbutz the problem from afar. But it *sounds* like it is a combination of not enough tuner and a "bit" of operator error. The internal tuners simply do not have enough capacity to meet the demands of all-band operation in some cases. I have the Ultralite Senior using the LDG Pro 100 tuner and I simply LOVE this antenna! I know that there is loss on some bands, but any so-called "all-band" antenna is going to be a compromise when compared to a dedicated, resonant antenna. I don't even LIKE tuners, but I have some requirements beyond the Amateur bands including US gov't SHARES and FEMA. I have to quickly move from one band to the other and, in order to do so, I have to accept some loss. However, I am VERY happy and surprised at the overall performance of *my* antenna. Actually, I'm told that it is unusually loud for a 100 watt station on a number of bands and quite readable on others (I don't HAVE to be the loudest thing going to be effective). I would guess----and that is what it is, a guess------that your internal tuner doesn't have the ability to match this antenna-----AND probably a number of others as well in multi-band service. Or you simply may have overlooked something in the installation---like location or height above ground. For every 10 users of a product, there's going to be one, perhaps, that is dissatisfied. With the Cobra, the reviews I have read are decidedly in favor of both the Junior AND the Senior Ultralight. You can't win 'em all! 73 K4KWH > Article: 225111 of rec.radio.amateur.antenna Date: Thu, 08 Jun 2006 22:30:01 -0500 From: Tom Ring Subject: Re: Have any of you mailed this to your ARRL Division directors and References: <6i2ig.3313$o4.2436@newsread2.news.pas.earthlink.net> Message-ID: <4488eb3a$0$1006$39cecf19@news.twtelecom.net> Slow Code wrote: > > > > I just knew none of you would take this serious and help. I bet you're > all democrats. > > sc Wrongo smart guy. And I only take things seriously that deserve it. tom K0TAR Article: 225112 of rec.radio.amateur.antenna Date: Thu, 08 Jun 2006 22:34:42 -0500 From: Tom Ring Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <4488ced6$0$3683$ecde5a14@news.coretel.net> Message-ID: <4488ec52$0$6141$39cecf19@news.twtelecom.net> clfe wrote: > Not really, but I'm not in a mood to argue about stupid shit - anymore. > Actually, I could care less. My ham days are few and far in between due to > all the ass holes on there ruining it for the rest of us. Maybe you're > right.......... the code really didn't keep the crud off the radios. Hell, > why even have a test at all. > > > Time to hang up your ticket I guess. We are all assholes, and you are the only "true ham radio operator" left. Go play with yourself. tom K0TAR Article: 225113 of rec.radio.amateur.antenna Date: Thu, 08 Jun 2006 22:37:14 -0500 From: Tom Ring Subject: Re: Give up CB for ham? References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> <4488ced6$0$3683$ecde5a14@news.coretel.net> Message-ID: <4488ecea$0$6141$39cecf19@news.twtelecom.net> clfe wrote: > Not really, but I'm not in a mood to argue about stupid shit - anymore. > Actually, I could care less. My ham days are few and far in between due to > all the ass holes on there ruining it for the rest of us. Maybe you're > right.......... the code really didn't keep the crud off the radios. Hell, > why even have a test at all. > And at least we admit who we are. You, on the other hand, are hiding. You are likely just a frigging troll that isn't even licensed. tom K0TAR Article: 225114 of rec.radio.amateur.antenna From: Buck Subject: Re: Buyer Beware - Cobra Ultralight Message-ID: References: <1149770557.629987.141180@i40g2000cwc.googlegroups.com> Date: Fri, 09 Jun 2006 00:05:47 -0400 On Fri, 09 Jun 2006 00:59:53 GMT, Owen Duffy wrote: >On Thu, 08 Jun 2006 20:33:12 -0400, Mike Coslo > wrote: > > >> I'd buy a tuner that will handle open wire feed, lose the 4:1 balun, >>and get on the air. > >Mike, did you notice "Mystery's" comment re spending more money on a >"tuner extender": "Not the answer I wanted to hear". She/he may be >even less interested in the spend on the tuner you describe. > >I agree with you that antenna looks worth a try / perseverance, but it >will probably need a wider range tuner than commonly fitted internal >to transceivers unless you experiment (what's that!) to find a >feedline length that the rig/runer accommodates on all bands, or >switch feedline lengths. > >Owen There really isn't a lot of information on the antenna on the page I saw: http://www.k1jek.com/. Many antennas have a spectrum of frequencies and their associated SWR. Knowing my internal tuner can only handle 8:1 but the antenna shows places I am interested in using with 12:1, would help me in my decision to choose the antenna or another. the OP didn't have that information. I know that internal antenna tuners are basically 'fine-tuners' and are very limited compared to external tuners. (at least Kenwood is clear about that in their instruction guides. ) I am not pointing a finger at either party, Mystery for not posting the information or some warning nor the OP for not asking. The Mystery page isn't very Corporate looking so one would have to assume some give and take in the purchase by both parties. Is there any reason the antenna can't be returned for a refund? If not, can it be sold to someone else who is interested? This is one of life's lessons learned. I just looked at the review of the antenna from eHam.com: =============== WA1BSB Rating: 5/5 Apr 24, 2006 14:29 Homemade Ultrilite Senior Time owned: 0 to 3 months Hi I went and made a homemade Ultrilite I too 3 conductor tv rotor cable 70 ft each side and mounted it to a modified 450 ohm ladderloc at the center I then ran about 50 ft of ladder line down to a 4.1 balun I know the plan calls for 100 ft but I just dint have the spot to coil it up The antenna is in a flat top configuration up between 2 trees about 80 ft up from the balun I ran about 70 ft of RG8X 50 ohm to my 746 Pro it tunes perfect on all bands 10-160 using the radios tuner 1.1 swr Anyhow it works with good signal reports so far on 40 and 20 meter Im looking forward to trying in 75 and 160 Anyhow bottom line whether you make one or buy it its quite the antenna I glad I got one 73s ================== There are many other reviews about the antennas, both jr and sr. Maybe there is a better configuration that will work, or he may need the tuner or tuner extender. Good luck Buck -- 73 for now Buck N4PGW Article: 225115 of rec.radio.amateur.antenna From: Cecil Moore Subject: Re: H FIELD ANTENNAS? References: <1149531001.503023.220830@g10g2000cwb.googlegroups.com> <1149542340.997313.268380@h76g2000cwa.googlegroups.com> <128bhjj6t6a6jb9@corp.supernews.com> <1149626355_40043@sp6iad.superfeed.net> <1149628313.756125.321140@j55g2000cwa.googlegroups.com> <1149640742_42035@sp6iad.superfeed.net> <1149675056.576658.92120@c74g2000cwc.googlegroups.com> <128dh45bejvrd5d@corp.supernews.com> <1149721730.564878.262550@j55g2000cwa.googlegroups.com> <128f0bfir75r9ec@corp.supernews.com> <1149737733.436349.216110@f6g2000cwb.googlegroups.com> <1149769611.319099.279910@j55g2000cwa.googlegroups.com> <1149819131.652479.124510@j55g2000cwa.googlegroups.com> Message-ID: Date: Fri, 09 Jun 2006 04:06:36 GMT w8ji@akorn.net wrote: > Now I'm not saying wind, dust, and moisture blowing across a > well-insulated antenna won't charge it faster, and make an antenna > without a ground path leak arc over some close gap more rapidly. I cured the problem by going to 1000v insulation on the antenna wire. 600v insulation didn't cure the problem. > I'm only saying I never have seen the noise pitch of what people > commonly call P-static track the actual number of droplets or dust > hitting the antenna, ... Uhhhh Tom, it doesn't happen in Georgia just as it doesn't happen in East Texas. If I had never lived in Queen Creek, Arizona, I never would have seen it either. -- 73, Cecil http://www.qsl.net/w5dxp Article: 225116 of rec.radio.amateur.antenna From: "Ed" References: <1149534276.955122.310050@i40g2000cwc.googlegroups.com> <4484dc50$0$1013$39cecf19@news.twtelecom.net> <128a2tq2vmeil53@corp.supernews.com> <5isa8294s7h2n8qtlpe39amh3qna7oa4hk@4ax.com> <4485851f$0$3708$ecde5a14@news.coretel.net> Subject: Re: Give up CB for ham? Message-ID: Date: Fri, 09 Jun 2006 04:55:44 GMT Give up CB for Ham.....what the hell would you be giving up? "Bill Turner" wrote in message news:co9h82d7fejjh7ac87n63pe9lgkcuu1120@4ax.com... > ORIGINAL MESSAGE: > > On Tue, 6 Jun 2006 09:36:21 -0400, "clfe" wrote: > > >>I am of the opinion that a 5 WPM at least - should be kept on as a >>requirement - as someday - it may be needed. Think not? Say you're in the >>m