Re: Topband: Radials help
Yes, FCP *was* originally designed to get small-lotters on top-band. My buddy Jack downsized and tore my heart out with his moaning about what he had done to his 160 results. But watch out when you say just. FCP has opened Pandora's box on the murky area of counterpoles for 160. We have the Reverse Beacon Network. And you will be hearing 160 4 squares built with FCP's, taking up less space than one conventional 1/4 wave vertical with 1/4 wave radials, eliminating the issue of what to do with crossing radials. And yes, there is a way to do this with grounded towers. There is a lot of stuff going on and gaining speed. Cat is out of the bag, boys. No going back. Short version: 1) All NEC based modeling programs have issues estimating ground losses. They are indemic, and may be unsolvable. 2) Using NEC based programs generating antenna patterns to estimate radial or counterpoise efficiency is NOT reliable. 3) Skywave comparisons using USA-wide and world-wide Reverse Beacon Network (RBN) ARE available and are increasingly pointing toward results that NEC programs currently poorly estimate. 4) Method for viewing RBN results 5) There is hope. Long version: The difficulty in comparing these antennas, comes in the weakness of either NEC2 or NEC4 based programs, including the professional version of EZNEC running the NEC4 engine, to properly estimate ground losses. The problem is that the ground method (Norton Sommerfield) can only use a monolithic completely uniform and homogenous ground material in its calculations, and cannot deal with layering or miscellaneous variations in real ground, nor with increasing water content with increasing depth, or a water table, all nearly universal components in any actual dirt beneath our feet, especially in building lots that have been graded and filled with leftover fill from other locations to provide a flat building surface or lawn area. Roy Lewallen, the author of EZNEC, finally was the source of my confirmation on this, though I suspected as much for quite a while. He simply states that the model UNDERESTIMATES the ground losses. He has real work with W8JI on this which he has not published, for whatever reason. I suspect that if he had the issues identified to his academic standards, he would publish, but that is a guess. In my mind, the original overwhelming persistent anecdotal indicator of such a modeling problem is the inability of any NEC model to predict the usually excellent success of an end-fed 80m halfwave L. In fact the models portray the EFHW as a significantly inferior choice to an inverted vee with the apex at the same height as the bend in the EFHW. Experience does not bear that out. I will rest easier when something in the modeling world shows what has gone on all my life with that antenna. In the mean time we are stuck that we don't have properly calculated losses for dirt underneath. Where there is this much smoke there is fire somewhere. Draw conclusions from NEC modeling programs embedding losses in gain figures at your own risk. We actually do have sky wave comparisons of different types of radials/counterpoises via the Reverse Beacon Network. Hard to say how many FCP based antennas are out there now, but the commercial FCP isolation transformer from Balun Designs is selling well. Last look, W0UCE's web page that describes the FCP ( http://www.w0uce.net/K2AVantennas.html) continues to average 70 hits a day from all over the world including such places as China and Indonesia. Wireman sold out all his double polyimide #14 wire used for hand-winding the transformer and had to scramble to restock. I've answered well over a hundred direct inquiries on variations on its use. It's clear that people are adapting the FCP to their own circumstances. * * If you want to see measurements, go to the reverse beacon network and look up K2AV, N1LN, N4XD, WX4G, W4KAZ for Jan 28 and 29 2012 (CQ160CW). All were QRO except W4KAZ who was running 100 watts. So adjust KAZ up 13 dB. All are in the general Raleigh area. AV and KAZ are over FCP's. XD and 4G are over radials, XD for sure a decent set of radials, not sure of WX4G's system. LN was multi-op, and has two phased verticals using ON4UN style loaded 1/8 wave elevated radials. WZ7I is the reverse beacon site which seems to have least amount of fading from our Raleigh area and is probably the best first hop RBN for measuring plain sky wave power. The poor propagation high absorbtion night of 28 Jan and WZ7I gives you a very steady all night comparison. There was almost no Europe heard by anyone in SE US Jan 28Z. Jan 29 was much better for Europe and seeing spots from here. Spots from GW8IZR are telling for transatlantic performance. To see how modest antennas stack up against the best of the best, add K3ZM to your comparisons. His contest station has a 160 meter 4 square over a salt marsh at the edge of salt water in directions north through east through south. There are some
Re: Topband: Radials help
On 02/12/2012 10:15 AM, Guy Olinger K2AV wrote: And you will be hearing 160 4 squares built with FCP's, taking up less space than one conventional 1/4 wave vertical with 1/4 wave radials, eliminating the issue of what to do with crossing radials. I plan to do a similar thing on 80m, though probably with double L antennas (vertical dipoles with the ends running horizontally). An array of 3 or 4 of those looks like it can outperform a single vertical with a good ground system (which I do not have space for), and give some directivity, for better reception. -- All rights reversed. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
New antenna models arenas ideas for them are one thing, but new laws of physics? It's great to experiment but you can only work around the fundementals. Discovering new principals is always in play, but that is very different from new configurations of metal. Even fractal antenna technology is based on all the base lines we know about RF. What would be useful is a Book of. Myths to save people lots of time and wire. Unfortunately it wouldn't be small. Sent from my iPad On Feb 10, 2012, at 20:51, Guy Olinger K2AV olin...@bellsouth.net wrote: Au contraire. We HAVE been building. What is different now is that we have affordable tools that Mssrs. Brown, Lewis and Epstein would surely drool over. The photographs in the study and some other related literature outline the difficulties they went through to produce the document. What we also have is the ability now to measure relative skywave signals (Remote Beacon Network) in a way that allows real statistical comparisons of stations in many different propagation situations and locations, and get it down to an accuracy of a dB or two, even for trans-oceanic paths. Now the old topic is popping up with NEW designs to test out, and it turns out there are some new things to compare. BLE had MONEY behind them, though they did have a wire budget theyeemt exhausted (113 radials instead of 120, the story is they ran out of wire). For BLE to have been truly comprehensive, they would have needed to redo it in Hawaii, North Carolina, and a half dozen other places, to add another matrix dimension to their figures in places with altogether different soil qualities. For our part, we just need to keep after the subject. People ARE putting up new designs on Top Band, and using them, and this annoyingly (for some) repetitive topic has been the vector for the new ideas. 73, Guy. On Fri, Feb 10, 2012 at 6:04 PM, Mark van Wijk pa...@home.nl wrote: It is time to stop talking. This topic pops up every six months or so for many years now. Go to a defined and mutual agreed property and build / test all mentioned radial models. No need to keep throwing theories, agreed/non agreed standards, computer models and hardly relevant what-works-for-me stories at each other. 73 Mark, PA5MW ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Hi, Trying to get up on top band on my small lot (free of antenna 'covenants') has forced the issue for me. I will be putting up a stick as tall as I can, with some sort of loading/matching, AND, as many radials as I live long enough to put down. That for transmit. I will use separate receive antennas and all of that for 160 through 40 or 30 meters. The big chunk of too low wire I have is so close to working well that it's taunting me to make the improvements. So I have found a place in the middle of my small back yard where I can set the tall stick and have some kind of symmetrical ground radial system. There is a nice, open, space where the trees won't encroach on the stick - almost dead center in my back yard. East-west radials can be near 50 feet long while north-south will have to be less than 20 feet unless I 'bend' the ends. I will get there. 73, Bill KU8H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Bill: Why struggle with or even bother putting down radials when you can use a Folded Counterpoise? Click on the link below for details: http://www.w0uce.net/K2AVantennas.html I will be putting up a stick as tall as I can, with some sort of loading/matching, AND, as many radials as I live long enough to put down ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Hi Jack, Are you saying that the FCP works just as well as an elevated or buried radial field??? I was under the impression that the FCP was just a way to get on 160 when there wasn't room for a radial field... Thanks for any feedback. 73, Ted K2QMF On Sat, 11 Feb 2012 12:39:35 -0500 W0UCE w0...@nc.rr.com writes: Bill: Why struggle with or even bother putting down radials when you can use a Folded Counterpoise? Click on the link below for details: http://www.w0uce.net/K2AVantennas.html I will be putting up a stick as tall as I can, with some sort of loading/matching, AND, as many radials as I live long enough to put down ___ UR RST IS ... ... ..9 QSB QSB - hw? BK 60-Year-Old Mom Looks 27 Mom Reveals Free Wrinkle Trick That Has Angered Doctors! http://thirdpartyoffers.juno.com/TGL3141/4f36afefa7d1b101a5c3st01vuc ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 02/11/2012 01:12 PM, k2...@juno.com wrote: Hi Jack, Are you saying that the FCP works just as well as an elevated or buried radial field??? I was under the impression that the FCP was just a way to get on 160 when there wasn't room for a radial field... The FCP, and also the double L antenna, work as well as the (poor) radial systems that many people can put up. It will not outperform a proper radial field with many dozens of quarter wave radials. According to NEC (which I know is not very accurate), both the vertical with FCP or a double L antenna are about 6dB below the output of a vertical over perfect ground - which a vertical with 120 quarter wave radials gets fairly close to. If you cannot fit a large radial field in your yard, and would be making do with a small one anyway, it may be worthwhile to just lift the whole antenna off the ground. This may lose you 1-3 dB over a good vertical with a smaller radial field, with the benefit of coming relatively close without having to dig up your yard. If you have the space and care about your signal strength, you'll probably be better off with a full radial field. -- All rights reversed. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help (Mark van Wijk) At-a-go Herb !!
I'm with you ! The delete key on the keyboard is for deleting. But I use the mouse button (open) on this list, and devour every bit of information. I assume I am in the majority here. To often we bow to minority opinion, being the gentlemen that we are. BTW, yesterday morning I called CQ/QRP with my new radials and nine (9) stations returned with a signal report !!! Thank you ! jim / W1FMR --- On Sat, 2/11/12, Herb Schoenbohm he...@vitelcom.net wrote: From: Herb Schoenbohm he...@vitelcom.net Subject: Re: Topband: Radials help (Mark van Wijk) To: topband@contesting.com Date: Saturday, February 11, 2012, 4:04 PM I disagree completely! I can quote a Chinese sage and author, his name escapes me..A person can earn more talking to an intelligent man for an hour than by reading volumes for decades. I learn something with most of the posts and hope they continue because this is what this reflector is all about I thought, the sharing of ideas and opinions about TB related issues.. Herb Schoenbohm, KV4FZ On 2/11/2012 4:47 PM, Panos Dalakos wrote: Dear moderator Mark PA5MW said: ...It is time to stop talking I agree absolutely. Maybe it's hard but all of us have a copy of ARRL Antenna Book or Low Band DXing. I think that it's enough for the 50% of us.Read, study and act. Let's help the reflector to be helpful for everyone. There are many other channels to communicate each-other as yahoo/skype/ovo/hamsphere etc. Today I received 7 issues of TB Digest. I don't open/read none issue. I read this topic accidentally looking the preview. I don't want to attack to anyone, so please don't bring out my post. With respect 73 de Panos SV1GRD ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help (Mark van Wijk)
Please do not abuse my wording. Or maybe I need to clarify. I DO welcome any discussion on exsting and new proposed antenna/ground systems. However, discussions tend to be jammed by people throwing in basic theories, papers, even laws of physics from those who seem to oppose a (valid) new idea (FCP). The next step is not to outsmart the guy via your kybd, but to built, test and compare. That's why I said stop the endless talking and start building. 73 Mark, PA5MW On 11 feb. 2012, at 21:47, Panos Dalakos pd...@tee.gr wrote: Dear moderator Mark PA5MW said: ...It is time to stop talking I agree absolutely. Maybe it's hard but all of us have a copy of ARRL Antenna Book or Low Band DXing. I think that it's enough for the 50% of us.Read, study and act. Let's help the reflector to be helpful for everyone. There are many other channels to communicate each-other as yahoo/skype/ovo/hamsphere etc. Today I received 7 issues of TB Digest. I don't open/read none issue. I read this topic accidentally looking the preview. I don't want to attack to anyone, so please don't bring out my post. With respect 73 de Panos SV1GRD ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help (Mark van Wijk)
Herb, Radio Antenna Engineering, published in 1952. It was written by Edmund Laport. It is available from Lulu Enterprises 3101 Hillsborough Street Raleigh, NC 27607 73 Price W0RI Mark, With all due respect to your comments.I want to know what I am building and why it is worth the effort before I commence. Accordingly discussion on this reflector is invaluable digesting the pros and cons of any ideas. I can learn so much here without digging into Maxwells Equations. Long ago I had a wonderful book Radio Antenna Engineering by Kraus and Terman published in 1952 but it was lost in Hurricane Hugo in 1989. Hopefully I can get another copy on eBay soon. Herb Schoenbohm, KV4FZ On 2/11/2012 7:06 PM, Mark van Wijk wrote: Please do not abuse my wording. Or maybe I need to clarify. I DO welcome any discussion on exsting and new proposed antenna/ground systems. However, discussions tend to be jammed by people throwing in basic theories, papers, even laws of physics from those who seem to oppose a (valid) new idea (FCP). The next step is not to outsmart the guy via your kybd, but to built, test and compare. That's why I said stop the endless talking and start building. 73 Mark, PA5MW ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help (Mark van Wijk)
Public domain edition also available in downloadable Format: http://snulbug.mtview.ca.us/books/RadioAntennaEngineering/ 73 Gary NL7Y Herb, Radio Antenna Engineering, published in 1952. It was written by Edmund Laport. It is available from Lulu Enterprises 3101 Hillsborough Street Raleigh, NC 27607 73 Price W0RI ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 2012-02-10, at 11:34 AM, Herb Schoenbohm wrote: One advantage of using insulate wire is that the velocity factor of the wire on ground or (ROG) allows for shorter lengths. This is important if you have limited yard space. Hi Herb, Interesting point...! According to either the ARRL ANTENNA HANDBOOK, or ON4UN's LOW-BAND DX HANDBOOK, the velocity factor of insulated wire placed atop the ground is 50%... I take that to mean that a 1/8-wave PHYSICALLY long wire radial has the ELECTRICAL equivalency of a wire radial that is 1/4-wave long... Maybe THAT'S the reason why I employ a total of 24 insulated radial wires, 65' long (each) beneath my L elements...it may not be an exact science, but hope springs eternal...! (Besides, have you seen the price of copper wire lately...?!). : ) ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 2/10/2012 12:48 PM, Eddy Swynar wrote: On 2012-02-10, at 11:34 AM, Herb Schoenbohm wrote: One advantage of using insulate wire is that the velocity factor of the wire on ground or (ROG) allows for shorter lengths. This is important if you have limited yard space. */Hi Herb,/* Interesting point...! According to either the ARRL */ANTENNA HANDBOOK/*, or ON4UN's */LOW-BAND DX HANDBOOK/*, the velocity factor of insulated wire placed atop the ground is *50%*... I take that to mean that a 1/8-wave /PHYSICALLY/long wire radial has the /ELECTRICAL/equivalency of a wire radial that is 1/4-wave long... Maybe /THAT'S/the reason why I employ a total of 24 insulated radial wires, 65' long (each) beneath my L elements...it may not be an exact science, but hope springs eternal...! (Besides, have you seen the price of copper wire lately...?!). *: )* */~73~ de Eddy VE3CUI - VE3XZ/* Eddy, The insulated rabbit wire ground screen laying on the ground...may provide a very adequate solution to those with limited space. The price of this material is very reasonable compared to the area it will cover...and will most likely last and perform better than bare plain chicken wire. Herb Schoenbohm, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
HM If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Inquiring minds want to know where this conversation is going. I understand that when you are doing radials, with a few they are part of the resonance factor for the vertical. However, after a dozen or so radials are installed the length does NOT necessarily determine resonance as the FIELD of radials becomes a composite Ground Plane. Bigger Ground Planes are Better!! Think salt water. So, IMHO, the 1/4 WL radius from the vertical is most likely at the break point for return vs cost. And the more Ground Plane you can place in that 1/2 WL diameter circle, the more efficient your vertical will be. If I was installing insulated radials I would make them full 1/4 WL regardless of the VF. It just makes good engineering sense. I am still learning, so if I am incorrect in any of these items please enlighten me. Mis dos centavos. 73 de Milt, N5IA -Original Message- From: Eddy Swynar Sent: Friday, February 10, 2012 9:48 AM To: he...@vitelcom.net Cc: topband@contesting.com Subject: Re: Topband: Radials help On 2012-02-10, at 11:34 AM, Herb Schoenbohm wrote: One advantage of using insulate wire is that the velocity factor of the wire on ground or (ROG) allows for shorter lengths. This is important if you have limited yard space. Hi Herb, Interesting point...! According to either the ARRL ANTENNA HANDBOOK, or ON4UN's LOW-BAND DX HANDBOOK, the velocity factor of insulated wire placed atop the ground is 50%... I take that to mean that a 1/8-wave PHYSICALLY long wire radial has the ELECTRICAL equivalency of a wire radial that is 1/4-wave long... Maybe THAT'S the reason why I employ a total of 24 insulated radial wires, 65' long (each) beneath my L elements...it may not be an exact science, but hope springs eternal...! (Besides, have you seen the price of copper wire lately...?!). : ) ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4801 - Release Date: 02/10/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Mis tres centavos: I think you are right on! There is confusion what is radial - as part of resonant antenna radiator vs. ground (plane) One has to look at the current distribution curves in EZNEC and se what current is in what, what is radiating and what is eaten up by the loses. One thing is, for the antenna hardware to form the radiation pattern. Another thing is contribution of the ground (plane) to forming that pattern (reflections, interaction). Oh, and the polarization thing. Mis quatro centavos: The best vertical monopole? 3/8 wave radiator, with 1/8 one (for some horizontal component) or two (for max vertical pol.) elevated radials over salt water mud or the biggest mother of ground screen/radials you can get. You will get most efficient radiator with most efficient mirror for most of RF down to the horizon. Proven by those on salty marshes, K6SE/K6ND stint from the Salt Lake, W8LRL with 360 radials 200 ft long, Team Vertical beach adventures, W3YOF, et al. (worth about 10 - 15 dB) Mis cinco centavo: Took me some 45 years to realize what makes antenna efficient: the area under the current distribution curve along the element. Thanks to the controversy about current in the loading coils please see http://www.k3bu.us/loadingcoils.htm This is also important in the controversy with Linear Loading vs. coil. Coil wins, current just drops along the coil, it is inline with element. LL superimposes currents (subtracts) especially when folded along the element, not welcome in multielement arrays. Sooo, if one thinks that radial is just ground that is not significant for antenna performance, go ahead. No mo' centavos 73 Yuri, K3BU.us who needs sunspots on 160 - Original Message - From: Milt -- N5IA Date: Friday, February 10, 2012 12:11 pm Subject: Re: Topband: Radials help To: Eddy Swynar , he...@vitelcom.net Cc: topband@contesting.com HM If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Inquiring minds want to know where this conversation is going. I understand that when you are doing radials, with a few they are part of the resonance factor for the vertical. However, after a dozen or so radials are installed the length does NOT necessarily determine resonance as the FIELD of radials becomes a composite Ground Plane. Bigger Ground Planes are Better!! Think salt water. So, IMHO, the 1/4 WL radius from the vertical is most likely at the break point for return vs cost. And the more Ground Plane you can place in that 1/2 WL diameter circle, the more efficient your vertical will be. If I was installing insulated radials I would make them full 1/4 WL regardless of the VF. It just makes good engineering sense. I am still learning, so if I am incorrect in any of these items please enlighten me. Mis dos centavos. 73 de Milt, N5IA -Original Message- From: Eddy Swynar Sent: Friday, February 10, 2012 9:48 AM To: he...@vitelcom.net Cc: topband@contesting.com Subject: Re: Topband: Radials help On 2012-02-10, at 11:34 AM, Herb Schoenbohm wrote: One advantage of using insulate wire is that the velocity factor of the wire on ground or (ROG) allows for shorter lengths. This is important if you have limited yard space. Hi Herb, Interesting point...! According to either the ARRL ANTENNA HANDBOOK, or ON4UN's LOW- BAND DX HANDBOOK, the velocity factor of insulated wire placed atop the ground is 50%... I take that to mean that a 1/8-wave PHYSICALLY long wire radial has the ELECTRICAL equivalency of a wire radial that is 1/4-wave long... Maybe THAT'S the reason why I employ a total of 24 insulated radial wires, 65' long (each) beneath my L elements...it may not be an exact science, but hope springs eternal...! (Besides, have you seen the price of copper wire lately...?!). : ) ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4801 - Release Date: 02/10/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
According to either the ARRL ANTENNA HANDBOOK, or ON4UN's LOW-BAND DX HANDBOOK, the velocity factor of insulated wire placed atop the ground is 50%... Unfortunately, and inconveniently, not to cast aspersions on anyone, BUT actual measurements in the Raleigh area showed that velocity factor of a wire laying on the ground and used for 160 meters was nothing like a uniform 50%. Measurements were taken with a 151' (46m) dipole on ground, with an analyzer to find primary resonance (and therefore velocity factor with a formula) and RF resistance at zero reactance, half of this being the effective series resistance of an electrical 1/4 wave radial identically installed in that spot. The measured velocity factor ranged from 45% to 80%, with the effective series resistance ranging from 30 to over a hundred ohms. There were wild variations both in velocity factor and effective series resistance on the same property, often had just by reorienting the DOG 90 degrees. These measurements were extremely dependent on the actual height above the dirt. Notching the wire down just into the dirt (not waiting for the grass to gradually bury it) produced the most repeatable measurements. If the end was not specifically insulated (like dipping in liquid tape, etc), the ends had to be bent up to get a measurement, because the ends are voltage nodes, even at the tiny antenna analyzer output voltages. Having an uninsulated end down just down in the damp botched the measurement. If any of you think an insulated radial field can just plopped down based on a formula on just any plot of land and be efficient, think again. All that is necessary to be abysmally INefficient is for the construction ground fill underneath your sod to be variable in composition, or contain metallic pipes or buried wires or a septic system. In this case your radials are no longer ELECTRICALLY dense and uniform, current distribution becomes wacky, effectively removing radials from the system, and the radial system has become an unbalanced ground heater, and quite inferior to an elevated counterpoise. (Sound familiar?) Have a read on W7ADC's (the excellent Mr. Archibald Doty) work in NCJ on radials. 1983 and 2011. Note the variability in the SAME dense radial field, and his conclusions. Largely ignored, and price paid for ignoring. Measurements made out in the convenient middle of a plowed and disc'd Iowa cornfield are idyllic because the dirt is uniform and wonderfully conductive, and UNAVAILABLE to the tortured topbanders trying to get anything to work on the only and the MF-dreadful plot of land they own. The starting presumption on a given plot of land should be that on/in-ground radials will NOT work well unless PROVEN otherwise. The odds are simply dreadful against it. I doubt they are even as good as one in a hundred that they could beat a well-designed elevated counterpoise. If one is stuck with in/on ground, then DEAL with the variability and INDIVIDUALLY PRUNE radials, notched into the dirt to their final resting place, to equal effective series resistance to FORCE the UNIFORM in dense and uniform. And if you're not willing to bother with dense, you're going to need an amp to compete with barefoot and QRP using efficient antennas. 73, Guy. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Pardon the dyslexia. Mr. Doty is W7ACD not W7ADC. On Fri, Feb 10, 2012 at 1:21 PM, Guy Olinger K2AV olin...@bellsouth.netwrote: Have a read on W7ADC's (the excellent Mr. Archibald Doty) work in NCJ on radials. 1983 and 2011. Note the variability in the SAME dense radial field, and his conclusions. Largely ignored, and price paid for ignoring. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 2012-02-10, at 1:21 PM, Guy Olinger K2AV wrote: If any of you think an insulated radial field can just plopped down based on a formula on just any plot of land and be efficient, think again. All that is necessary to be abysmally INefficient is for the construction ground fill underneath your sod to be variable in composition, or contain metallic pipes or buried wires or a septic system. In this case your radials are no longer ELECTRICALLY dense and uniform, current distribution becomes wacky, effectively removing radials from the system, and the radial system has become an unbalanced ground heater, and quite inferior to an elevated counterpoise. (Sound familiar?) Hi Guy, All this talk about idealized radial systems, vs. compromised radial fields, hearkens me back to the words of an old Rolling Stones song, to whit: You can't always get what you want, but if you try sometimes you just might find you get what you need. I'll never have the proverbial 120 full-length radials here (what I may want), so I'll just have to make do with my 24 one-eighth wave compromises (what I need---certainly better than no radials at all! Hi). ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Not enough room for towers and radials? Antennas aren't big enough? Here's an employment opportunity to work on ELF antennas at the 2 megawatt U.S. Navy NAA transmitter in sunny, warm Cutler, Maine. https://applicationmanager.gov/Questionnaire.aspx?ID=4313317PreviewType=Questionnaire http://www.navy-radio.com/commsta/cutler.htm 73 Frank W3LPL Original message Date: Fri, 10 Feb 2012 13:34:05 -0500 From: Eddy Swynar deswy...@xplornet.ca Subject: Re: Topband: Radials help To: Guy Olinger K2AV olin...@bellsouth.net Cc: topband@contesting.com, he...@vitelcom.net On 2012-02-10, at 1:21 PM, Guy Olinger K2AV wrote: If any of you think an insulated radial field can just plopped down based on a formula on just any plot of land and be efficient, think again. All that is necessary to be abysmally INefficient is for the construction ground fill underneath your sod to be variable in composition, or contain metallic pipes or buried wires or a septic system. In this case your radials are no longer ELECTRICALLY dense and uniform, current distribution becomes wacky, effectively removing radials from the system, and the radial system has become an unbalanced ground heater, and quite inferior to an elevated counterpoise. (Sound familiar?) Hi Guy, All this talk about idealized radial systems, vs. compromised radial fields, hearkens me back to the words of an old Rolling Stones song, to whit: You can't always get what you want, but if you try sometimes you just might find you get what you need. I'll never have the proverbial 120 full-length radials here (what I may want), so I'll just have to make do with my 24 one-eighth wave compromises (what I need---certainly better than no radials at all! Hi). ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 2012-02-10, at 1:52 PM, Guy Olinger K2AV wrote: It's not to not try anything. It's to try something that you know will work, once you *know* what you have to work with. The ARRL and ON4UN material presume uniformity. That, unfortunately, is only true where it's true, and it's not true often enough. Hi Guy, I thought that was exactly what I was doing here at my QTH, i.e. not NOT trying anything, but at least doing something. Far too many words of advice / tribal knowledge that I've seen over the years in the matter of radial fields amounted to simply ...lay down as many wires as you can. PERIOD. That's neither enlightening, nor encouraging. The guidelines presented in the ARRL's John's book, flawed though they may be when presented with an imperfect world, at least offer a place to start, in the absence of knowing exactly what might lie immediately below one's sod... I guess one can analyze some things to death. There are trade-offs between qualitative realities vs. quantitative ones---that's just a fact of life! ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On Fri, 2012-02-10 at 14:09 -0500, Eddy Swynar wrote: On 2012-02-10, at 1:52 PM, Guy Olinger K2AV wrote: It's not to not try anything. It's to try something that you know will work, once you *know* what you have to work with. The ARRL and ON4UN material presume uniformity. That, unfortunately, is only true where it's true, and it's not true often enough. Hi Guy, I thought that was exactly what I was doing here at my QTH, i.e. not NOT trying anything, but at least doing something. Far too many words of advice / tribal knowledge that I've seen over the years in the matter of radial fields amounted to simply ...lay down as many wires as you can. PERIOD. That's neither enlightening, nor encouraging. The guidelines presented in the ARRL's John's book, flawed though they may be when presented with an imperfect world, at least offer a place to start, in the absence of knowing exactly what might lie immediately below one's sod... I guess one can analyze some things to death. There are trade-offs between qualitative realities vs. quantitative ones---that's just a fact of life! ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK When I made engine parts we sometimes shot the engineers and went into full production. 73, Bill KU8H ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 2/10/2012 1:11 PM, Milt -- N5IA wrote: If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Answer: Because the FCC requires it as part of your AM application. Some stations that were required to protect a distant station on the same channel but away from the area they wanted to cover, even applied for a waivers with a deliberately poor ground system in the protected direction ...but the FCC said no way Jose. Another consulting engineer when modeling a slant wire shunt fed and running test FSM noticed some cancellation in the opposite direction of the slant wire shunt fed tower. This appeared a sensible solution to enhanced protection without the addition of another tower and expensive pahser, not to mention the cost of additional real estate. Again the boys at 1919 M Street said no. (The Portals today) With the price of copper skyrocketing the amount of theft in some parts of the country is unbelievable. AM stations are immediate targets as thieves just pull up the systems with a winch or just hook it to the bumper and drive off into seclusion and roll it up in the back of a truck. Some station owners in PR have opted to plow in barbed wire as a lower cost alternative to bare copper. So far none of the barbed wire buried ground systems have not been touched. Herb Schoenbohm, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
The 120 comes from the watershed 1937 Brown Lewis and Eppstein study now found in the IEEE journals. There were distinct characteristics to 120 times 0.4 wl (actually 115) that improved results even vs. 60. That a deficient radial system on one side has any significant reduction in that direction alone VS THE OTHER DIRECTIONS is a fairly well debunked idea. That the missing radials reduce radiation in all directions, due to diminished efficiency, is not disputed. 73, Guy. On Fri, Feb 10, 2012 at 2:54 PM, Herb Schoenbohm he...@vitelcom.net wrote: On 2/10/2012 1:11 PM, Milt -- N5IA wrote: If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Answer: Because the FCC requires it as part of your AM application. Some stations that were required to protect a distant station on the same channel but away from the area they wanted to cover, even applied for a waivers with a deliberately poor ground system in the protected direction ...but the FCC said no way Jose. Another consulting engineer when modeling a slant wire shunt fed and running test FSM noticed some cancellation in the opposite direction of the slant wire shunt fed tower. This appeared a sensible solution to enhanced protection without the addition of another tower and expensive pahser, not to mention the cost of additional real estate. Again the boys at 1919 M Street said no. (The Portals today) With the price of copper skyrocketing the amount of theft in some parts of the country is unbelievable. AM stations are immediate targets as thieves just pull up the systems with a winch or just hook it to the bumper and drive off into seclusion and roll it up in the back of a truck. Some station owners in PR have opted to plow in barbed wire as a lower cost alternative to bare copper. So far none of the barbed wire buried ground systems have not been touched. Herb Schoenbohm, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 2/10/2012 5:03 PM, Guy Olinger K2AV wrote: The 120 comes from the watershed 1937 Brown Lewis and Eppstein study now found in the IEEE journals. There were distinct characteristics to 120 times 0.4 wl (actually 115) that improved results even vs. 60. That a deficient radial system on one side has any significant reduction in that direction alone VS THE OTHER DIRECTIONS is a fairly well debunked idea. That the missing radials reduce radiation in all directions, due to diminished efficiency, is not disputed. 73, Guy. Guy, What about the slant wire cause at least some directive component in the direction of the slant wire? Herb, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
What radial length does the FCC requirement stipulate for the 120 radials? Quarter, half or a full wavelength? How did they come to this decision since Brown, Lewis and Eppstein used 0.4wl? Mike N2MS - Original Message - From: Guy Olinger K2AV olin...@bellsouth.net To: he...@vitelcom.net Cc: topband@contesting.com Sent: Fri, 10 Feb 2012 21:03:26 - (UTC) Subject: Re: Topband: Radials help The 120 comes from the watershed 1937 Brown Lewis and Eppstein study now found in the IEEE journals. There were distinct characteristics to 120 times 0.4 wl (actually 115) that improved results even vs. 60. That a deficient radial system on one side has any significant reduction in that direction alone VS THE OTHER DIRECTIONS is a fairly well debunked idea. That the missing radials reduce radiation in all directions, due to diminished efficiency, is not disputed. 73, Guy. On Fri, Feb 10, 2012 at 2:54 PM, Herb Schoenbohm wrote: On 2/10/2012 1:11 PM, Milt -- N5IA wrote: If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Answer: Because the FCC requires it as part of your AM application. Some stations that were required to protect a distant station on the same channel but away from the area they wanted to cover, even applied for a waivers with a deliberately poor ground system in the protected direction ...but the FCC said no way Jose. snip ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Off top my head, it would seem the slant wire would work to create a directional effect of one sort or other, depending on the specifics, but I have no clue why the FCC dissed that one. They usually attach some technical explanation to rulings. You have access to the specific proceedings? I could come up with a dozen speculations about it, but that's all they'd be. -- Guy. On Fri, Feb 10, 2012 at 5:13 PM, Herb Schoenbohm he...@vitelcom.net wrote: On 2/10/2012 5:03 PM, Guy Olinger K2AV wrote: The 120 comes from the watershed 1937 Brown Lewis and Eppstein study now found in the IEEE journals. There were distinct characteristics to 120 times 0.4 wl (actually 115) that improved results even vs. 60. That a deficient radial system on one side has any significant reduction in that direction alone VS THE OTHER DIRECTIONS is a fairly well debunked idea. That the missing radials reduce radiation in all directions, due to diminished efficiency, is not disputed. 73, Guy. Guy, What about the slant wire cause at least some directive component in the direction of the slant wire? Herb, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
They have stray radiation that the FCC's computer can not model. On 2/10/12 5:43 PM, Guy Olinger K2AV wrote: Off top my head, it would seem the slant wire would work to create a directional effect of one sort or other, depending on the specifics, but I have no clue why the FCC dissed that one. They usually attach some technical explanation to rulings. You have access to the specific proceedings? I could come up with a dozen speculations about it, but that's all they'd be. -- Guy. On Fri, Feb 10, 2012 at 5:13 PM, Herb Schoenbohmhe...@vitelcom.net wrote: On 2/10/2012 5:03 PM, Guy Olinger K2AV wrote: The 120 comes from the watershed 1937 Brown Lewis and Eppstein study now found in the IEEE journals. There were distinct characteristics to 120 times 0.4 wl (actually 115) that improved results even vs. 60. That a deficient radial system on one side has any significant reduction in that direction alone VS THE OTHER DIRECTIONS is a fairly well debunked idea. That the missing radials reduce radiation in all directions, due to diminished efficiency, is not disputed. 73, Guy. Guy, What about the slant wire cause at least some directive component in the direction of the slant wire? Herb, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
The paper by Rudy Severns, EXPERIMENTAL DETERMINATION OF GROUND SYSTEM PERFORMANCE FOR HF VERTICALS PART 7 GROUND SYSTEMS WITH MISSING SECTORS is illuminating. WX7G On Feb 10, 2012 2:03 PM, Guy Olinger K2AV olin...@bellsouth.net wrote: The 120 comes from the watershed 1937 Brown Lewis and Eppstein study now found in the IEEE journals. There were distinct characteristics to 120 times 0.4 wl (actually 115) that improved results even vs. 60. That a deficient radial system on one side has any significant reduction in that direction alone VS THE OTHER DIRECTIONS is a fairly well debunked idea. That the missing radials reduce radiation in all directions, due to diminished efficiency, is not disputed. 73, Guy. On Fri, Feb 10, 2012 at 2:54 PM, Herb Schoenbohm he...@vitelcom.net wrote: On 2/10/2012 1:11 PM, Milt -- N5IA wrote: If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Answer: Because the FCC requires it as part of your AM application. Some stations that were required to protect a distant station on the same channel but away from the area they wanted to cover, even applied for a waivers with a deliberately poor ground system in the protected direction ...but the FCC said no way Jose. Another consulting engineer when modeling a slant wire shunt fed and running test FSM noticed some cancellation in the opposite direction of the slant wire shunt fed tower. This appeared a sensible solution to enhanced protection without the addition of another tower and expensive pahser, not to mention the cost of additional real estate. Again the boys at 1919 M Street said no. (The Portals today) With the price of copper skyrocketing the amount of theft in some parts of the country is unbelievable. AM stations are immediate targets as thieves just pull up the systems with a winch or just hook it to the bumper and drive off into seclusion and roll it up in the back of a truck. Some station owners in PR have opted to plow in barbed wire as a lower cost alternative to bare copper. So far none of the barbed wire buried ground systems have not been touched. Herb Schoenbohm, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
It is time to stop talking. This topic pops up every six months or so for many years now. Go to a defined and mutual agreed property and build / test all mentioned radial models. No need to keep throwing theories, agreed/non agreed standards, computer models and hardly relevant what-works-for-me stories at each other. 73 Mark, PA5MW ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Here is a link to that paper. It is easy see what field a radiator of X height will produce with varying number of radials from 2 to 113. From the graphs 15 radials and a 45 deg tower gets reasonably close to the ideal. It also shows a 45 deg tower with 113 radials is almost as good as a 90 deg. http://rfry.org/Software%20Download/Ground%20Systems%20-%20Brown,%20Lewis%20and%20Epstein%201937.pdf On 2/10/12 4:03 PM, Guy Olinger K2AV wrote: The 120 comes from the watershed 1937 Brown Lewis and Eppstein study now found in the IEEE journals. There were distinct characteristics to 120 times 0.4 wl (actually 115) that improved results even vs. 60. That a deficient radial system on one side has any significant reduction in that direction alone VS THE OTHER DIRECTIONS is a fairly well debunked idea. That the missing radials reduce radiation in all directions, due to diminished efficiency, is not disputed. 73, Guy. On Fri, Feb 10, 2012 at 2:54 PM, Herb Schoenbohmhe...@vitelcom.net wrote: On 2/10/2012 1:11 PM, Milt -- N5IA wrote: If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Answer: Because the FCC requires it as part of your AM application. Some stations that were required to protect a distant station on the same channel but away from the area they wanted to cover, even applied for a waivers with a deliberately poor ground system in the protected direction ...but the FCC said no way Jose. Another consulting engineer when modeling a slant wire shunt fed and running test FSM noticed some cancellation in the opposite direction of the slant wire shunt fed tower. This appeared a sensible solution to enhanced protection without the addition of another tower and expensive pahser, not to mention the cost of additional real estate. Again the boys at 1919 M Street said no. (The Portals today) With the price of copper skyrocketing the amount of theft in some parts of the country is unbelievable. AM stations are immediate targets as thieves just pull up the systems with a winch or just hook it to the bumper and drive off into seclusion and roll it up in the back of a truck. Some station owners in PR have opted to plow in barbed wire as a lower cost alternative to bare copper. So far none of the barbed wire buried ground systems have not been touched. Herb Schoenbohm, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On 2/10/2012 6:43 PM, Guy Olinger K2AV wrote: Off top my head, it would seem the slant wire would work to create a directional effect of one sort or other, depending on the specifics, but I have no clue why the FCC dissed that one. They usually attach some technical explanation to rulings. You have access to the specific proceedings? I could come up with a dozen speculations about it, but that's all they'd be. -- Guy. On Fri, Feb 10, 2012 at 5:13 PM, Herb Schoenbohmhe...@vitelcom.net wrote: No papers that I know of Guy, just the word of a consulting engineer who said he applied in the 60's and said it would not be considered as a solution for even a slight pattern control to protect another station. He finally had to go to a two tower array, another ground system, a phaser, a day night switching control and a lot of bucks for the owner. Station now are allowed lowering power to accomplish protection but back then it was 250w, 500w, or 1KW, etc. Nothing in between for a single tower set up. Now they permit single tower daytimers to operate at night with very low power levels as low as a few watts to keep their station on at night. I am sort of certain that some ham has modeled the pros and cons of a slant wire feed for a grounded tower but I have never seen such results published. Some hams tell me they do this to bring the feed wire into the shack so they can use the tuner there to get a decent match across the band. Herb, KV4FZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
The broadcasters also dont fall for the resonance bit either; very few radiators plus radials have anything to do with an actual resonance. All of this was explained back in the 30's. Carl KM1H - Original Message - From: Milt -- N5IA n...@zia-connection.com To: Eddy Swynar deswy...@xplornet.ca; he...@vitelcom.net Cc: topband@contesting.com Sent: Friday, February 10, 2012 12:11 PM Subject: Re: Topband: Radials help HM If that is the case, WHY do the pro broadcasters install all 120 radials at full length; even bare wire buried a couple of inches underground? Inquiring minds want to know where this conversation is going. I understand that when you are doing radials, with a few they are part of the resonance factor for the vertical. However, after a dozen or so radials are installed the length does NOT necessarily determine resonance as the FIELD of radials becomes a composite Ground Plane. Bigger Ground Planes are Better!! Think salt water. So, IMHO, the 1/4 WL radius from the vertical is most likely at the break point for return vs cost. And the more Ground Plane you can place in that 1/2 WL diameter circle, the more efficient your vertical will be. If I was installing insulated radials I would make them full 1/4 WL regardless of the VF. It just makes good engineering sense. I am still learning, so if I am incorrect in any of these items please enlighten me. Mis dos centavos. 73 de Milt, N5IA -Original Message- From: Eddy Swynar Sent: Friday, February 10, 2012 9:48 AM To: he...@vitelcom.net Cc: topband@contesting.com Subject: Re: Topband: Radials help On 2012-02-10, at 11:34 AM, Herb Schoenbohm wrote: One advantage of using insulate wire is that the velocity factor of the wire on ground or (ROG) allows for shorter lengths. This is important if you have limited yard space. Hi Herb, Interesting point...! According to either the ARRL ANTENNA HANDBOOK, or ON4UN's LOW-BAND DX HANDBOOK, the velocity factor of insulated wire placed atop the ground is 50%... I take that to mean that a 1/8-wave PHYSICALLY long wire radial has the ELECTRICAL equivalency of a wire radial that is 1/4-wave long... Maybe THAT'S the reason why I employ a total of 24 insulated radial wires, 65' long (each) beneath my L elements...it may not be an exact science, but hope springs eternal...! (Besides, have you seen the price of copper wire lately...?!). : ) ~73~ de Eddy VE3CUI - VE3XZ ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.1913 / Virus Database: 2112/4801 - Release Date: 02/10/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1424 / Virus Database: 2112/4801 - Release Date: 02/10/12 ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
Buzz, Instead of 500-foot rolls of insulated wire, I found it more cost effective to buy a 1,000-foot roll of 14-2 with ground wire from Home Depot. I stretched about 200 feet at a time along my property. From an electrical supply house I bought an inexpensive tool that zips easily through the outer jacket. I then pulled the kraft paper from the bare copper ground wire. Use the bare copper wire and the white insulated wire to cross your driveway. The white insulation will get dirty soon and blend in with the soil, and the bare copper will quickly tarnish and be less conspicuous. 73, Charles, W2SH From: b...@logi.us Date: Wed, 9 Nov 2011 20:49:57 + To: topband@contesting.com Subject: Topband: Radials help Installing 80 and 160 verticals and was going to use 14 gauge uninsulated solid copper wire for radials. Little dirt here, mostly limestone and caliche. Is there any reason to use insulated wire? No one seems to sell bare wire anymore (Lowes, Home Depot), but it would hide better than colored insulated wire. I have lots of deer, squirrels, porcupines, possums, skunks, but no hogs. Half the radials will cross the caliche driveway. We have only had 3 of rain all year, so the ground is essentially cement. Radials will just be laying on top held in by steel staples. Grass may cover in years to come! Was going to start with 16 1/4 wave 160 meter radials. Any ideas, suggestions on where to buy radial wire or how to install greatly appreciated off reflector. Thanks Buzz N5UR Bandera Texas, Cowboy Capital of the World ___ UR RST IS ... ... ..9 QSB QSB - hw? BK ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Radials help
There are definitive studies which show that for a few radials making them long does not do as much as making them half as long and doubling the number... i.e. twice the number of radials for the same total wire length improves your far field strength.. I know it seems counter intuitive, but physics often is... You need a dense mat close in at the feed point to gather the return currents so for the first 30 radials 1/8 wave is sufficient... Once you hit the 30 radial mark, then you can go back and start adding longer radials in-between the short radials you started with... Then if you get sufficient radials down, 60+, there will be a further, but small, increase in efficiency by adding on to the end of the shorter radials... There is no need in a ham antenna installation for all the radials to be the same length... And you can spread the installation out over time... Your first 30 short radials will be the most bang for your buck... Also, there is nothing magical about 1/4 or 1/2 wave for radials... As soon as you lay a reasonant length of wire on the ground it is no longer resonant at the frequency you thought it was... Read the writings of Rudy, N6LP and you will be well ahead of the game... http://www.antennasbyn6lf.com/ denny / k8do ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Re: Topband: Radials help
On Thu, Nov 10, 2011 at 6:41 AM, Dennis OConnor ad4hk2...@yahoo.com wrote: There is no need in a ham antenna installation for all the radials to be the same length... This is only true to any degree if you are talking about buried, BARE radials. If also uniformly spaced, elevated or insulated radials make use of uniformity to achieve a degree of loss-avoiding field cancellation underneath the antenna. Current in elevated or insulated radials shorter than an electrical quarter wavelength will tend toward a longer radial, due to its lower individual impedance. In a non-uniform collection of radials, the least reactive lengths at the operating frequency will carry more current. 73, Guy. ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
Topband: Radials help
Installing 80 and 160 verticals and was going to use 14 gauge uninsulated solid copper wire for radials. Little dirt here, mostly limestone and caliche. Is there any reason to use insulated wire? No one seems to sell bare wire anymore (Lowes, Home Depot), but it would hide better than colored insulated wire. I have lots of deer, squirrels, porcupines, possums, skunks, but no hogs. Half the radials will cross the caliche driveway. We have only had 3 of rain all year, so the ground is essentially cement. Radials will just be laying on top held in by steel staples. Grass may cover in years to come! Was going to start with 16 1/4 wave 160 meter radials. Any ideas, suggestions on where to buy radial wire or how to install greatly appreciated off reflector. Thanks Buzz N5UR Bandera Texas, Cowboy Capital of the World ___ UR RST IS ... ... ..9 QSB QSB - hw? BK
