Topband: Antennas
For many years I tried every possible ground mounted short vertical with my 35' city limit. >From the base of my tower I installed about 1000' of buried radials in my >sprinkler trenches and connected to the pool steel when it was going in. I tried base, center, and top loaded verticals, loading the tower gamma style and with a slant feed. Year after year I worked the same stations in ARRL 160 and none east of the Mississippi. The first antenna that got me into the east coast was a 1/4 wave of 450 ohm ladder line shorted at the far end and fed at ground with 50 ohm coax. It was 35' up and the rest out to a tree about 25' high. Only DX for years was a few PAC, JAs and SA. My current antenna which has brought WAC, and many EU stations exceeds the city limit but they haven't bother me about it. I have my roof covered with radials and use an inverted L about 20' above ground, 33 up and the rest out to the tree but about 35' up now. There are 4 full size 160 radials snaked around and other for 80/40/30/20/15/12/10. It has HB 40m and 80m traps built to take the Alpha and my 3KW Nye can tune it to any band. The ONLY ground mounted vertical that ever worked for me was a full size "beer can" 40 M vertical with 60 full size radials. DX magnet with my AR-3, VF-1 and DX-20 hi hi Rick, N6PE == Talk is cheap... except when Congress does it. ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
Interspersed. On Wed, Dec 12, 2012 at 7:10 PM, DAVID CUTHBERT wrote: > Guy, > > here is where I believe your mysterious extra "loss" in NEC is coming > from. You are reading the "average gain" loss. NEC calculates that by > integrating the power at infinity and dividing by the power into the > antenna. This accounts for the far-far field ground losses that vertically > polarized radiation encounters. > Yes, indeed. But where do those ground losses ACTUALLY start? Why is it that what you call "far far" ground losses can vary by raising very low feed points small amounts above ground that could not possibly be pattern changing in the distance? What you call "far far" losses start at the BASE of the antenna IF the lossy dielectric of the earth is NOT effectively shielded by an opposite and equal counter-field supplied by dense radials (why proper radials are best). This is a kind of loss that Roy Lewallen terms underestimated in NEC4. If one understands that the losses to ground in the distance start at the end of a dense radial field, and beyond that point manage to lose 3.9 dB for a 1/4 wave system, then what happens to the level of loss when the radius or density of the shielding effect is reduced. What if the shielding extent and density is reduced to NOTHING by use of a ground rod as a counterpoise? When all of this was being shaken out, nobody with money was carefully calculating the Sommerfield ground estimation method for a BC tower connected to a ground rod, or ten foot radials. Gotta remember all that stuff was NOT written for hams, NOT written for us and our faint imitations of proper commercial solutions. NEC is just not calibrated for a lot of the stuff that we try over really dreadful dirt. We're just hoping that the extrapolation down into too-small attempts holds. The extrapolation seems to have some severe problems. > > But, this is not how we report the radiation efficiency of a vertical. > That is defined as the radiated energy in the far field (but not too far) > divided by the power into the antenna. > Doesn't a term such as radiated energy in the near far field have to run in lock step via formula with the EZNEC loss figure? Using mV/m figures at a mile or a kilometer is FAR, isn't it? And if it doesn't track, is the term worth anything for real application? The range of the integration is the same for both processes, and with one degree points in EZNEC the difference should be way down in the decimal points. And are you saying that the 3.9 dB out there isn't actually lost, that it's really there somehow because its not seen in something called radiation efficiency? The experience says that the loss is there, and the bulk of anecdotal material says the loss can be worse than calculated. I'm just saying that we mark as risky, possibly really bad, anything not reasonably close to full size, dense and uniform all around, or not specifically designed to operate without commercial radials with specific attention to minimization of ground induction from counterpoise and vertical radiators. Faint imitations of radials are going to cost us loss, and the really unfortunate ones can send us down toward 20 dB. The sooner we figure out exactly why the better. Denial doesn't cut it anymore. RBN is double blind. RBN is essentially verifying the anecdotes rather than contradicting them. 73, Guy. > Dave WX7G > > > On Wed, Dec 12, 2012 at 4:34 PM, Guy Olinger K2AV > wrote: > >> [I may have sent an incomplete version of something on this topic. >> Apologies] >> >> 6 dB would be someone's calculation based on currents. The sometimes >> abysmal performance of a ground rod based vertical system cannot be >> explained by 6 dB. Cutting my amp from 1500w to 375watts just doesn't get >> bad enough. Not close. >> >> Part of the problem is that we figure all the current in the vertical is >> free and clear to useful radiation and is not affected by the RF >> "appearance" of the ground. >> >> You can model a near perfect commercial grade radial field, with a radial >> system apparent series resistance of a few tenths of an ohm, and NEC4 will >> still come back with an overall loss of 3 to 4 dB. There is no >> book-keeping of that loss in the 34 ohm vertical radiator in series with >> the near zero resistance of the radials, as people typically talk about it. >> >> >> If I run my EZNEC Pro NEC4 3D all points azimuth and elevation run for a >> gold standard commercial installation, 120 1/4 wave buried radials in >> "average" ground, at the bottom of the main window I will get a rather >> typical 3.9 dB overall loss. IF we have to understand loss as only >> book-kept in the feed resistance numbers, one would have to APPORTION the >> 34 ohms resistance to account for the loss. That would be 47 percent in >> the pattern and 53 percent lost somewhere, by some means, 16 ohms >> apportioned out to the pattern with 18 ohms of loss somewhere, but not in >> the radials and not in the
Topband: GAP VERTICAL QUESTION version 2
First let me thank everyone for the responses . As constructive as they are of course they tell me that the Gap antennas will not suffice. Martin DM4IM said it best I guess "On 160m however, its just like someone pulls the plug when i switch from a 160m inv L over FCP to the Gap." Now this says a lot for the FCP Inverted L.. and tells me exactly what I needed to know... it is a direct comparison nearly instantaniously. As many have said before there is no free lunch and one of the premisis that I learned years ago (and maybe wanted to ignore) is that signal is related in part to the capture area of the antenna OR put simply longer is better. In any event my initial hope was to be able to put up a vertical for 160M and up on top of an appartment building and if it had a metal pan roof.. well that would be even better. The problem is that most appartments do not allow wire antennas in the common areas and around my area there are few appartment complexes that back up to any real woods. I just know there will not be any place to put up an inverted L let along a Beverage... HOHUM.!!! Long Live Seal Team VI http://www.qsl.net/wa3mej/index.htm - Original Message - ___ Topband reflector - topband@contesting.com
Topband: Fwd: Fw: GAP VERTICAL QUESTION
> One thing to consider (a non-Gap subject as this thread is drifting, sorry) > is to make your 80M loop into a 160 dipole when desired if a 160 aerial isn't > available. It can be done mechanically by separating the loop half-way around > (via a relay, or connecting drooping ends from the ground...done that once), > or electrically by inserting a wound coil at that point (not sure of the coil > specs, however. Just read about it being done. Might be another Amateur Urban > Legend). > > A side note. The tall GAP Voyager did serve some useful purpose during the > forest fire that burned my tree supports out in the woods. I disassembled it > before the fire arrived and used the aluminum tubing to hold several common > yard sprinklers off the ground and staked in a perimeter around the > dwellings. The sprinklers and water pumped from a nearby lake saved the > structures. > > The Titan I returned to town, but was discarded when I put up the tower and > SteppIR beam. > > 73, Gary NL7Y > > >> Personally, I use an 80 M loop - I like it especially for stateside contest >> like Sweep or FD. Nice solid signal on 40M and 80M. It does much better >> than the Titan. But the Titan is much less maintenance and I don't have to >> put it up and rebuild it each year. >> >> With two hurricanes, no guying and no maintenance work at all, the antenna >> stays up, good SWR and I can make the occasional contact. Will I ever be >> the big dog - nope. I had a much better station in the mid-west, but we all >> make compromises,. >> > ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
Guy, here is where I believe your mysterious extra "loss" in NEC is coming from. You are reading the "average gain" loss. NEC calculates that by integrating the power at infinity and dividing by the power into the antenna. This accounts for the far-far field ground losses that vertically polarized radiation encounters. But, this is not how we report the radiation efficiency of a vertical. That is defined as the radiated energy in the far field (but not too far) divided by the power into the antenna. Dave WX7G On Wed, Dec 12, 2012 at 4:34 PM, Guy Olinger K2AV wrote: > [I may have sent an incomplete version of something on this topic. > Apologies] > > 6 dB would be someone's calculation based on currents. The sometimes > abysmal performance of a ground rod based vertical system cannot be > explained by 6 dB. Cutting my amp from 1500w to 375watts just doesn't get > bad enough. Not close. > > Part of the problem is that we figure all the current in the vertical is > free and clear to useful radiation and is not affected by the RF > "appearance" of the ground. > > You can model a near perfect commercial grade radial field, with a radial > system apparent series resistance of a few tenths of an ohm, and NEC4 will > still come back with an overall loss of 3 to 4 dB. There is no > book-keeping of that loss in the 34 ohm vertical radiator in series with > the near zero resistance of the radials, as people typically talk about it. > > > If I run my EZNEC Pro NEC4 3D all points azimuth and elevation run for a > gold standard commercial installation, 120 1/4 wave buried radials in > "average" ground, at the bottom of the main window I will get a rather > typical 3.9 dB overall loss. IF we have to understand loss as only > book-kept in the feed resistance numbers, one would have to APPORTION the > 34 ohms resistance to account for the loss. That would be 47 percent in > the pattern and 53 percent lost somewhere, by some means, 16 ohms > apportioned out to the pattern with 18 ohms of loss somewhere, but not in > the radials and not in the vertical wire. > > Great radials. Top of the line radials. BUT there is still some > mechanism draining off 53 percent of the power. The math in NEC 4 is > doing and sensing something that explains loss not book-kept in our > all-loss-is-shown-in-the-feed Z mental picture. > > Where's the loss, loss that does not change the feed Z as it comes and > goes. How does it work? Can this non-Z-changing loss increase without the > commercial radials and a wire fed right at the ground? One could picture > my installing a really good antenna at a place looking at a fairly distant > horizon. However, I could have trucks and bulldozers built a 1000 foot > high dirt wall encircling my place a mile away, and my feed Z would not > change. The wall would just soak up RF that otherwise would be out doing > wonderful things at low angles. > > How much additional does "unshielded" dirt underneath a naked vertical > soak up in terms of dB that does not alter the feed Z? > > Persons unnamed in 1995 recommended two 1/4 wave radials on the ground. I > remember that K4CIA from the other side of town, running QRP on his well > constructed 160 vertical could often beat me out running 100 watts. What I > had was like running QRP on a good antenna. > > We don't know everything. And there are a lot of people that have awful > results with hack job radials. We need to quit recommending hack jobs > until we know exactly why they do or do not work, and can explain a FAR > greater percentage of the anecdotal material than we can now, and can > explain how in some scenarios how we can get results that ARE plainly down > 20. If we're not careful, at some point we can be blowing off the > essential majority story because we just don't want to listen. > > 73, Guy > > On Wed, Dec 12, 2012 at 3:17 PM, DAVID CUTHBERT wrote: > >> Correction, 100X the loss. >> >> The deal difference between a single ground rod and a BC station ground >> will be about 6 dB. >> >> Dave WX7G >> On Dec 12, 2012 1:13 PM, "DAVID CUTHBERT" wrote: >> >> > 20 dB implies that the ground system loss is 10X the inverted-L >> radiation >> > resistance. >> > >> > This would result in an input resistance of 250 ohms and a minimum VSWR >> if >> > 5:1. >> > >> > I don't think that is what the real deal will deliver, do you? >> > >> > Dave WX7G >> > On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" >> > wrote: >> > >> >> With the following caveat: The very sparse and short buried radial >> >> systems >> >> he is showing are FAR more lossy in practice than shown in his gain >> >> tables. >> >> Four twenty foot buried radials beneath a 1/4 wave L on 160, could >> place >> >> you down 20 dB. You really can't do that as your 160 meter counter >> poise >> >> and expect decent results. You can end feed the same wire on 80/40/30 >> >> meters (full wave worth of wire in the L on 80m) with four buried 20 >> foot >> >> radials and it will
Topband: elevated radial question
I'm finalizing the layout for a tree hung T loaded vertical for TB, about 85' to the top, two x 45' mostly horizontal loading wires, and radials elevated 10' above (much?) better than average soil, at least this time of year when I have standing water among the trees. (Redmond, WA) I'm taking W8JI's advice and going with the top loaded vertical rather than a delta loop, particularly after I determined I can squeeze seven fairly symmetrical 130' radials in (with a cooperative neighbor). I plan a switched series capacitor feed for bandwidth, with the antenna resonant at 1815KHz or so. Now two questions before stringing wire - 1. My new DXE 4 square receive array is outside the radial field, with the center of the square 82' from the radials perimeter. Does it matter if the end of one radial is about 30' from a corner 4sq antenna, or should I pitch the radials to maximize the separation? Even as much as a 90 degree (or more) segment with no radials? At 90 degree pitch the nearest radial ends would be about 80' from their nearest 4sq antenna. 2. Now the unusual circumstance - there is a 56' x 70' steel building entirely inside the radial circle, but at the perimeter. Steel roof, walls, and Ufer grounded to the perimeter footing. My thinking, not sure I'm correct, is to NOT attach any radials to the building (12' to eves, 14' to peak), but nestle it between 2 radials with about 15' feet of minimum clearance. OTOH, I can connect one or more radials to the steel, or run one or more insulated radials over the roof to a support off the perimeter end of the building. And then OTOH, the steel sure makes this part of the radial field pretty high conductivity. This one is definitely not in the handbooks or in ON4UN or in the N6LF QEX articles. btw I have a SteppIR BigIR vertical going on the center of this roof as a secondary/backup HF antenna. Inputs appreciated, Grant KZ1W ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
On 2012-12-12, at 6:28 PM, Scott MacKenzie wrote: > Personally, I use an 80 M loop - I like it especially for stateside contest > like Sweep or FD. Nice solid signal on 40M and 80M. By far, the absolute BEST DX antenna that I've ever had the pleasure of using for the low bands is the inverted Bobtail array (40-meters): no radial fields required, super-easy to feed, all-wire construction, bi-directional, "stealthy", and---for me, at least---a real band "opener" on both direct, and long path, circuits... I only wish that I had the wherewithal here to put one up for Topband! I guess it could be done by bending the three vertical elements alright, but I'd still have trouble here attaining even a 60' elevation...(sigh!). ~73~ de Eddy VE3CUI - VE3XZ ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
[I may have sent an incomplete version of something on this topic. Apologies] 6 dB would be someone's calculation based on currents. The sometimes abysmal performance of a ground rod based vertical system cannot be explained by 6 dB. Cutting my amp from 1500w to 375watts just doesn't get bad enough. Not close. Part of the problem is that we figure all the current in the vertical is free and clear to useful radiation and is not affected by the RF "appearance" of the ground. You can model a near perfect commercial grade radial field, with a radial system apparent series resistance of a few tenths of an ohm, and NEC4 will still come back with an overall loss of 3 to 4 dB. There is no book-keeping of that loss in the 34 ohm vertical radiator in series with the near zero resistance of the radials, as people typically talk about it. If I run my EZNEC Pro NEC4 3D all points azimuth and elevation run for a gold standard commercial installation, 120 1/4 wave buried radials in "average" ground, at the bottom of the main window I will get a rather typical 3.9 dB overall loss. IF we have to understand loss as only book-kept in the feed resistance numbers, one would have to APPORTION the 34 ohms resistance to account for the loss. That would be 47 percent in the pattern and 53 percent lost somewhere, by some means, 16 ohms apportioned out to the pattern with 18 ohms of loss somewhere, but not in the radials and not in the vertical wire. Great radials. Top of the line radials. BUT there is still some mechanism draining off 53 percent of the power. The math in NEC 4 is doing and sensing something that explains loss not book-kept in our all-loss-is-shown-in-the-feed Z mental picture. Where's the loss, loss that does not change the feed Z as it comes and goes. How does it work? Can this non-Z-changing loss increase without the commercial radials and a wire fed right at the ground? One could picture my installing a really good antenna at a place looking at a fairly distant horizon. However, I could have trucks and bulldozers built a 1000 foot high dirt wall encircling my place a mile away, and my feed Z would not change. The wall would just soak up RF that otherwise would be out doing wonderful things at low angles. How much additional does "unshielded" dirt underneath a naked vertical soak up in terms of dB that does not alter the feed Z? Persons unnamed in 1995 recommended two 1/4 wave radials on the ground. I remember that K4CIA from the other side of town, running QRP on his well constructed 160 vertical could often beat me out running 100 watts. What I had was like running QRP on a good antenna. We don't know everything. And there are a lot of people that have awful results with hack job radials. We need to quit recommending hack jobs until we know exactly why they do or do not work, and can explain a FAR greater percentage of the anecdotal material than we can now, and can explain how in some scenarios how we can get results that ARE plainly down 20. If we're not careful, at some point we can be blowing off the essential majority story because we just don't want to listen. 73, Guy On Wed, Dec 12, 2012 at 3:17 PM, DAVID CUTHBERT wrote: > Correction, 100X the loss. > > The deal difference between a single ground rod and a BC station ground > will be about 6 dB. > > Dave WX7G > On Dec 12, 2012 1:13 PM, "DAVID CUTHBERT" wrote: > > > 20 dB implies that the ground system loss is 10X the inverted-L radiation > > resistance. > > > > This would result in an input resistance of 250 ohms and a minimum VSWR > if > > 5:1. > > > > I don't think that is what the real deal will deliver, do you? > > > > Dave WX7G > > On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" > > wrote: > > > >> With the following caveat: The very sparse and short buried radial > >> systems > >> he is showing are FAR more lossy in practice than shown in his gain > >> tables. > >> Four twenty foot buried radials beneath a 1/4 wave L on 160, could > place > >> you down 20 dB. You really can't do that as your 160 meter counter > poise > >> and expect decent results. You can end feed the same wire on 80/40/30 > >> meters (full wave worth of wire in the L on 80m) with four buried 20 > foot > >> radials and it will be an excellent antenna. This is due to the high Z > >> feed at the ground with current max AWAY from the feed point. > >> > >> A quarter wave L on 160 MUST deal with the counterpoise loss issues, one > >> way or another. > >> > >> 73, Guy > >> > >> On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee >> >wrote: > >> > >> > This wonderful article written by L.B.Cebic W4RNL sure can make you a > >> > believer in a simple wire inverted L. It is the last antenna > discussed. > >> > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf > >> > > >> > A $3 wire pulled up into a tree will beat just about any commercial > >> > antenna… because it is longer. So on low bands it has increased band > >> width > >> > and effic
Re: Topband: Fw: GAP VERTICAL QUESTION
Personally, I use an 80 M loop - I like it especially for stateside contest like Sweep or FD. Nice solid signal on 40M and 80M. It does much better than the Titan. But the Titan is much less maintenance and I don't have to put it up and rebuild it each year. With two hurricanes, no guying and no maintenance work at all, the antenna stays up, good SWR and I can make the occasional contact. Will I ever be the big dog - nope. I had a much better station in the mid-west, but we all make compromises,. -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary and Kathleen Pearse Sent: Wednesday, December 12, 2012 3:44 PM To: topband List Subject: Re: Topband: Fw: GAP VERTICAL QUESTION FWIW, at one point on a 5 acre remote parcel I had a GAP Voyager, GAP Titan, 80/160 parallel Inv-L over 120/125' radials, a 160M Inv-V, a F-12 C-4SXL beam at 54', and homemade vertical fan dipoles for 10-40M. Tall 70-85' trees that later burned in a forest fire held up the wires. The GAPS were just that...always at the bottom of the RF food chain. The vertical dipoles were down in strength from the F-12 beam some, yet I heard and worked everything the beam did when compared. They are a good alternative to a vert on the same band if supports are available. I had verts for 40 and 20 over a dense radial field (~60), but removed them when the vertical dipoles prevailed. The Inv-L worked all bands 10-160, with varying results depending on the other antennas and signal direction/time of day. I fed it with both coax plus RF chokes at both ends of the run, and twin-lead over the few years it was up. It was a full size vert on 80 due to a second wire parallel to the 160 L fed at the same point. The twin-lead fed Inv-V did the same for all bands, and had good gain on 10-40 off the ends. The Inv-L usually beat the Inv-V at the same height (~80') on 80-160. In my experience an Inv-L for 160 would be a good choice if one could only have one wire. Tuning is critical for multi-band ops. During this experiment I also had a 2-el horizontal loop for 80 at 55', which was excellent for NVIS and out to ~2500 miles from KL7, and a 1000' horizontal loop at 50-80', which was not worth the effort to build. Today, only the 80 loop and F-12 beam remain at that location. 73, Gary NL7Y ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
Well, Tom I operate from a small city lot, although I do have some tall trees! I've done OK on 160 and 80 with a 160 inverted L and full size 80m GP - both with elevated resonant radials. (The 160 radials did meander a bit) I've worked some really good DX on 160 - VK6, 3B8, JA and 3Y0 etc. - and some deep Russians. Biggest problem for me, in the city was not being heard, it was HEARING! Once I put up a terminated loop "Kaz" antenna, with a preamp for receiving. All that changed - a LOT! I believe that guys are missing a good bet by not trying the elevated resonant radials under their 160 and 80m antennas -even if they have to meander a bit. In my experience,the main challenge on 160 is HEARING! Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Wednesday, December 12, 2012 4:25 PM To: Guy Olinger K2AV; Ashton Lee Cc: k...@arrl.net; topband@contesting.com Subject: Re: Topband: Fw: GAP VERTICAL QUESTION With the following caveat: The very sparse and short buried radial systems he is showing are FAR more lossy in practice than shown in his gain tables. Four twenty foot buried radials beneath a 1/4 wave L on 160, could place you down 20 dB. 1% efficiency, and 99% of power dissipated in the earth with a small ground system on an inverted L antenna? I don't think that is very likely without a feedpoint in the hundreds or thousands of ohms. Even a single ground rod is likely around 50-100 ohms, and would produce signals much stronger than that. There are ways to create modest feed impedances with extreme loss. Researchers at GAP, through great effort, have found a way to combine terrible efficiency with a reasonable feedpoint impedance. Based on measurements, the GAP is somewhere around 1% efficiency on 160 and around 3% efficiency on 80 meters. Most of this loss is because the loading system (at least in large part) uses a coaxial stub, which has a Q low in the double digits, and has higher voltage applied at a poor ground system. I'm also sure much of the loss is caused by folding of current back and forth, cancelling radiation and driving radiation resistance through the floor. The bulk of the feed impedance on low bands is dissipative. It is a very high angle radiator on ten meters, but is "OK" on most other bands. This is quite an achievement, giving low SWR and mobile-antenna performance without actually using an antenna 8 feet long, and without a physical resistor. << You really can't do that as your 160 meter counter poise and expect decent results. You can end feed the same wire on 80/40/30 meters (full wave worth of wire in the L on 80m) >>> It is a half wave on 80. <<>> Four short radials on an L are really not that bad compared to an antenna engineered to have very low radiation resistance and very high internal loss. I know or knew people who were quite successful with small grounds on inverted L's. An old friend (now SK) in Toledo had an inverted L on a small city lot, probably no more than ten feet deep from the house to the fence, and he was consistently within a few dB of my full size 160 vertical in a swampy area. His only long radial ran parallel to the L and underneath the L. His radials were buried to hide them, and his L was right against his ranch style house. Other people had similar antennas. One fellow had nothing but ground rods, he had no radials at all, except the wires that connected the rods. His signal was certainly less than my 1/4 wave tower with a large radial system in wet black sandy loam, but it was probably not more than 5-10 dB less. Another station was always within an S unit on any report anywhere, even Australia, and he was on a corner city lot with less than 20 feet to the sidewalks for radials and a 30-35 ft high inverted L. My conclusion is it takes great effort, or significant incredible failure, to manage to be 10-20 dB down. I really get quite a chuckle out of anecdotal day-and-night performance reports, when I think back at some of the absolutely rubbish that ran neck and neck with a quarter wave vertical in black wet swamp soil. I wonder more about how poor the one antenna was than how good the second one was. 73 Tom ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
Guy, you make it sound like magic. See the IEEE paper RADIATION EFFICIENCY AND INPUT IMPEDANCE OF MONOPOLE ELEMENTS WITH RADIAL-WIRE GROUND PLANES IN PROXIMITY TO EARTH Dave WX7G On Dec 12, 2012 3:13 PM, "Guy Olinger K2AV" wrote: > Not all loss is visible as series resistance in the counterpoise system, > which is the tack you are taking. Note that a dummy load is 50 ohms, and > does not radiate worth a hoot. > > It takes modeling to identify some situations. One of my favorites in > NEC4 results in a max gain of -18 dBi or so. This is compared to a > commercial BC 1/4 wave of plus 1.2 dBi in the same ground. The reason for > the extreme loss is completely counter-intuitive. > > We have a lot of mental simplification devices for thinking about > antennas. In the end you need something to add up all the induced > currents, all the losses > > > > On Wed, Dec 12, 2012 at 3:13 PM, DAVID CUTHBERT wrote: > >> 20 dB implies that the ground system loss is 10X the inverted-L radiation >> resistance. >> >> This would result in an input resistance of 250 ohms and a minimum VSWR if >> 5:1. >> >> I don't think that is what the real deal will deliver, do you? >> >> Dave WX7G >> On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" >> wrote: >> >> > With the following caveat: The very sparse and short buried radial >> systems >> > he is showing are FAR more lossy in practice than shown in his gain >> tables. >> > Four twenty foot buried radials beneath a 1/4 wave L on 160, could >> place >> > you down 20 dB. You really can't do that as your 160 meter counter >> poise >> > and expect decent results. You can end feed the same wire on 80/40/30 >> > meters (full wave worth of wire in the L on 80m) with four buried 20 >> foot >> > radials and it will be an excellent antenna. This is due to the high Z >> > feed at the ground with current max AWAY from the feed point. >> > >> > A quarter wave L on 160 MUST deal with the counterpoise loss issues, one >> > way or another. >> > >> > 73, Guy >> > >> > On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee > > >wrote: >> > >> > > This wonderful article written by L.B.Cebic W4RNL sure can make you a >> > > believer in a simple wire inverted L. It is the last antenna >> discussed. >> > > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf >> > > >> > > A $3 wire pulled up into a tree will beat just about any commercial >> > > antenna… because it is longer. So on low bands it has increased band >> > width >> > > and efficiency, and on higher bands it has gain. Yes, I know , some of >> > that >> > > high band gain is horizontally polarized, but that's not all bad. Just >> > get >> > > the vertical portion 33 feet or so and you'll be happy as Larry. The >> > > article shows that an extensive radial field may not be necessary. >> > > >> > > And a wire is a lot less visible than a big hunk of aluminum. Without >> > > trees, just top load a 43 foot (or possibly even shorter) vertical. >> The >> > top >> > > loading could be a T just as easily as an L. People can argue that one >> > all >> > > day. >> > > >> > > >> > > >> > > >> > > On Dec 12, 2012, at 11:30 AM, k6xt wrote: >> > > >> > > > My first antenna, still in use, on moving to CO is a GAP Titan, >> > > advertised to load up 80 thru 10 including WARC bands. The Titan is a >> bit >> > > shorter than Voyager, 28 feet or something like it. The advertising is >> > > correct, it loads up 180 thru 10. >> > > > >> > > > But wait. Is it effective on all those bands? No. >> > > > >> > > > On 80 its a dummy load. On 40 it works extremely well after I added >> a >> > > one foot extension to the bottom wire that encircles the antenna. In >> some >> > > cases it is the equal of my shorty HyGain 40 at 70 ft - which probably >> > says >> > > more about the HyGain than the GAP. For the rest its better on the >> > > traditional bands than the WARC bands. It worked a lot of DX for me >> for >> > the >> > > couple years it was my only antenna. >> > > > >> > > > Carrying my experience to the few feet taller Voyager, and from what >> > > I've been told by Voyager users, the ant will meet its spec which is >> to >> > > load up on the low bands. Expectation wise I'd expect it to be like >> the >> > > Titan. It loads up but is otherwise a dummy load. Maybe with a batch >> of >> > > radials it could be made to work as well as any other extremely short >> > > vertical or GP. >> > > > >> > > > Not to say there's anything wrong with GAP. My brother had up an R7 >> > > which he rated about like the GAP on bands both cover. Those multiband >> > > halfwave short verticals work but you get what you pay for. >> > > > >> > > > 73 Art K6XT~~ >> > > > Success is going from failure to failure without a loss of >> enthusiasm. >> > > > ARRL, GMCC, CW OPS, NAQCC >> > > > ARRL TA >> > > > >> > > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: >> > > >> With the prospect of downsizing and moving into senior housing in >> the >> > > future >> > > >> I
Re: Topband: Fw: GAP VERTICAL QUESTION
Not all loss is visible as series resistance in the counterpoise system, which is the tack you are taking. Note that a dummy load is 50 ohms, and does not radiate worth a hoot. It takes modeling to identify some situations. One of my favorites in NEC4 results in a max gain of -18 dBi or so. This is compared to a commercial BC 1/4 wave of plus 1.2 dBi in the same ground. The reason for the extreme loss is completely counter-intuitive. We have a lot of mental simplification devices for thinking about antennas. In the end you need something to add up all the induced currents, all the losses On Wed, Dec 12, 2012 at 3:13 PM, DAVID CUTHBERT wrote: > 20 dB implies that the ground system loss is 10X the inverted-L radiation > resistance. > > This would result in an input resistance of 250 ohms and a minimum VSWR if > 5:1. > > I don't think that is what the real deal will deliver, do you? > > Dave WX7G > On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" > wrote: > > > With the following caveat: The very sparse and short buried radial > systems > > he is showing are FAR more lossy in practice than shown in his gain > tables. > > Four twenty foot buried radials beneath a 1/4 wave L on 160, could place > > you down 20 dB. You really can't do that as your 160 meter counter poise > > and expect decent results. You can end feed the same wire on 80/40/30 > > meters (full wave worth of wire in the L on 80m) with four buried 20 foot > > radials and it will be an excellent antenna. This is due to the high Z > > feed at the ground with current max AWAY from the feed point. > > > > A quarter wave L on 160 MUST deal with the counterpoise loss issues, one > > way or another. > > > > 73, Guy > > > > On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee > >wrote: > > > > > This wonderful article written by L.B.Cebic W4RNL sure can make you a > > > believer in a simple wire inverted L. It is the last antenna discussed. > > > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf > > > > > > A $3 wire pulled up into a tree will beat just about any commercial > > > antenna… because it is longer. So on low bands it has increased band > > width > > > and efficiency, and on higher bands it has gain. Yes, I know , some of > > that > > > high band gain is horizontally polarized, but that's not all bad. Just > > get > > > the vertical portion 33 feet or so and you'll be happy as Larry. The > > > article shows that an extensive radial field may not be necessary. > > > > > > And a wire is a lot less visible than a big hunk of aluminum. Without > > > trees, just top load a 43 foot (or possibly even shorter) vertical. The > > top > > > loading could be a T just as easily as an L. People can argue that one > > all > > > day. > > > > > > > > > > > > > > > On Dec 12, 2012, at 11:30 AM, k6xt wrote: > > > > > > > My first antenna, still in use, on moving to CO is a GAP Titan, > > > advertised to load up 80 thru 10 including WARC bands. The Titan is a > bit > > > shorter than Voyager, 28 feet or something like it. The advertising is > > > correct, it loads up 180 thru 10. > > > > > > > > But wait. Is it effective on all those bands? No. > > > > > > > > On 80 its a dummy load. On 40 it works extremely well after I added a > > > one foot extension to the bottom wire that encircles the antenna. In > some > > > cases it is the equal of my shorty HyGain 40 at 70 ft - which probably > > says > > > more about the HyGain than the GAP. For the rest its better on the > > > traditional bands than the WARC bands. It worked a lot of DX for me for > > the > > > couple years it was my only antenna. > > > > > > > > Carrying my experience to the few feet taller Voyager, and from what > > > I've been told by Voyager users, the ant will meet its spec which is to > > > load up on the low bands. Expectation wise I'd expect it to be like the > > > Titan. It loads up but is otherwise a dummy load. Maybe with a batch of > > > radials it could be made to work as well as any other extremely short > > > vertical or GP. > > > > > > > > Not to say there's anything wrong with GAP. My brother had up an R7 > > > which he rated about like the GAP on bands both cover. Those multiband > > > halfwave short verticals work but you get what you pay for. > > > > > > > > 73 Art K6XT~~ > > > > Success is going from failure to failure without a loss of > enthusiasm. > > > > ARRL, GMCC, CW OPS, NAQCC > > > > ARRL TA > > > > > > > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: > > > >> With the prospect of downsizing and moving into senior housing in > the > > > future > > > >> I am starting to look at vertical antennas that will allow me to > > > continue > > > >> this wonderful hobby.? I have heard "some" good things about the GAP > > > series > > > >> of antennas but the company says they do not need radials on most of > > > them > > > >> and that worries me.? Over the years I have become very skeptical > > about > > > >> claims and the other BS put out by m
Re: Topband: Fw: GAP VERTICAL QUESTION
With the following caveat: The very sparse and short buried radial systems he is showing are FAR more lossy in practice than shown in his gain tables. Four twenty foot buried radials beneath a 1/4 wave L on 160, could place you down 20 dB. 1% efficiency, and 99% of power dissipated in the earth with a small ground system on an inverted L antenna? I don't think that is very likely without a feedpoint in the hundreds or thousands of ohms. Even a single ground rod is likely around 50-100 ohms, and would produce signals much stronger than that. There are ways to create modest feed impedances with extreme loss. Researchers at GAP, through great effort, have found a way to combine terrible efficiency with a reasonable feedpoint impedance. Based on measurements, the GAP is somewhere around 1% efficiency on 160 and around 3% efficiency on 80 meters. Most of this loss is because the loading system (at least in large part) uses a coaxial stub, which has a Q low in the double digits, and has higher voltage applied at a poor ground system. I'm also sure much of the loss is caused by folding of current back and forth, cancelling radiation and driving radiation resistance through the floor. The bulk of the feed impedance on low bands is dissipative. It is a very high angle radiator on ten meters, but is "OK" on most other bands. This is quite an achievement, giving low SWR and mobile-antenna performance without actually using an antenna 8 feet long, and without a physical resistor. << You really can't do that as your 160 meter counter poise and expect decent results. You can end feed the same wire on 80/40/30 meters (full wave worth of wire in the L on 80m) >>> It is a half wave on 80. <<>> Four short radials on an L are really not that bad compared to an antenna engineered to have very low radiation resistance and very high internal loss. I know or knew people who were quite successful with small grounds on inverted L's. An old friend (now SK) in Toledo had an inverted L on a small city lot, probably no more than ten feet deep from the house to the fence, and he was consistently within a few dB of my full size 160 vertical in a swampy area. His only long radial ran parallel to the L and underneath the L. His radials were buried to hide them, and his L was right against his ranch style house. Other people had similar antennas. One fellow had nothing but ground rods, he had no radials at all, except the wires that connected the rods. His signal was certainly less than my 1/4 wave tower with a large radial system in wet black sandy loam, but it was probably not more than 5-10 dB less. Another station was always within an S unit on any report anywhere, even Australia, and he was on a corner city lot with less than 20 feet to the sidewalks for radials and a 30-35 ft high inverted L. My conclusion is it takes great effort, or significant incredible failure, to manage to be 10-20 dB down. I really get quite a chuckle out of anecdotal day-and-night performance reports, when I think back at some of the absolutely rubbish that ran neck and neck with a quarter wave vertical in black wet swamp soil. I wonder more about how poor the one antenna was than how good the second one was. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
FWIW, at one point on a 5 acre remote parcel I had a GAP Voyager, GAP Titan, 80/160 parallel Inv-L over 120/125' radials, a 160M Inv-V, a F-12 C-4SXL beam at 54', and homemade vertical fan dipoles for 10-40M. Tall 70-85' trees that later burned in a forest fire held up the wires. The GAPS were just that...always at the bottom of the RF food chain. The vertical dipoles were down in strength from the F-12 beam some, yet I heard and worked everything the beam did when compared. They are a good alternative to a vert on the same band if supports are available. I had verts for 40 and 20 over a dense radial field (~60), but removed them when the vertical dipoles prevailed. The Inv-L worked all bands 10-160, with varying results depending on the other antennas and signal direction/time of day. I fed it with both coax plus RF chokes at both ends of the run, and twin-lead over the few years it was up. It was a full size vert on 80 due to a second wire parallel to the 160 L fed at the same point. The twin-lead fed Inv-V did the same for all bands, and had good gain on 10-40 off the ends. The Inv-L usually beat the Inv-V at the same height (~80') on 80-160. In my experience an Inv-L for 160 would be a good choice if one could only have one wire. Tuning is critical for multi-band ops. During this experiment I also had a 2-el horizontal loop for 80 at 55', which was excellent for NVIS and out to ~2500 miles from KL7, and a 1000' horizontal loop at 50-80', which was not worth the effort to build. Today, only the 80 loop and F-12 beam remain at that location. 73, Gary NL7Y ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
Correction, 100X the loss. The deal difference between a single ground rod and a BC station ground will be about 6 dB. Dave WX7G On Dec 12, 2012 1:13 PM, "DAVID CUTHBERT" wrote: > 20 dB implies that the ground system loss is 10X the inverted-L radiation > resistance. > > This would result in an input resistance of 250 ohms and a minimum VSWR if > 5:1. > > I don't think that is what the real deal will deliver, do you? > > Dave WX7G > On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" > wrote: > >> With the following caveat: The very sparse and short buried radial >> systems >> he is showing are FAR more lossy in practice than shown in his gain >> tables. >> Four twenty foot buried radials beneath a 1/4 wave L on 160, could place >> you down 20 dB. You really can't do that as your 160 meter counter poise >> and expect decent results. You can end feed the same wire on 80/40/30 >> meters (full wave worth of wire in the L on 80m) with four buried 20 foot >> radials and it will be an excellent antenna. This is due to the high Z >> feed at the ground with current max AWAY from the feed point. >> >> A quarter wave L on 160 MUST deal with the counterpoise loss issues, one >> way or another. >> >> 73, Guy >> >> On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee > >wrote: >> >> > This wonderful article written by L.B.Cebic W4RNL sure can make you a >> > believer in a simple wire inverted L. It is the last antenna discussed. >> > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf >> > >> > A $3 wire pulled up into a tree will beat just about any commercial >> > antenna… because it is longer. So on low bands it has increased band >> width >> > and efficiency, and on higher bands it has gain. Yes, I know , some of >> that >> > high band gain is horizontally polarized, but that's not all bad. Just >> get >> > the vertical portion 33 feet or so and you'll be happy as Larry. The >> > article shows that an extensive radial field may not be necessary. >> > >> > And a wire is a lot less visible than a big hunk of aluminum. Without >> > trees, just top load a 43 foot (or possibly even shorter) vertical. The >> top >> > loading could be a T just as easily as an L. People can argue that one >> all >> > day. >> > >> > >> > >> > >> > On Dec 12, 2012, at 11:30 AM, k6xt wrote: >> > >> > > My first antenna, still in use, on moving to CO is a GAP Titan, >> > advertised to load up 80 thru 10 including WARC bands. The Titan is a >> bit >> > shorter than Voyager, 28 feet or something like it. The advertising is >> > correct, it loads up 180 thru 10. >> > > >> > > But wait. Is it effective on all those bands? No. >> > > >> > > On 80 its a dummy load. On 40 it works extremely well after I added a >> > one foot extension to the bottom wire that encircles the antenna. In >> some >> > cases it is the equal of my shorty HyGain 40 at 70 ft - which probably >> says >> > more about the HyGain than the GAP. For the rest its better on the >> > traditional bands than the WARC bands. It worked a lot of DX for me for >> the >> > couple years it was my only antenna. >> > > >> > > Carrying my experience to the few feet taller Voyager, and from what >> > I've been told by Voyager users, the ant will meet its spec which is to >> > load up on the low bands. Expectation wise I'd expect it to be like the >> > Titan. It loads up but is otherwise a dummy load. Maybe with a batch of >> > radials it could be made to work as well as any other extremely short >> > vertical or GP. >> > > >> > > Not to say there's anything wrong with GAP. My brother had up an R7 >> > which he rated about like the GAP on bands both cover. Those multiband >> > halfwave short verticals work but you get what you pay for. >> > > >> > > 73 Art K6XT~~ >> > > Success is going from failure to failure without a loss of enthusiasm. >> > > ARRL, GMCC, CW OPS, NAQCC >> > > ARRL TA >> > > >> > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: >> > >> With the prospect of downsizing and moving into senior housing in the >> > future >> > >> I am starting to look at vertical antennas that will allow me to >> > continue >> > >> this wonderful hobby.? I have heard "some" good things about the GAP >> > series >> > >> of antennas but the company says they do not need radials on most of >> > them >> > >> and that worries me.? Over the years I have become very skeptical >> about >> > >> claims and the other BS put out by most companies ( maybe it is a >> > function >> > >> of age I dunno) so I wonder if these antennas really work.? The two >> > antennas >> > >> that I am interested are the Voyager DX for 160/80/40? and the Eagle >> DX >> > for >> > >> the rest of the bands. >> > >> >> > >> So my question is does anyone have actual experience with these >> > antennas >> > >> (especially the voyager) as compared to other antennas for a specific >> > >> frequency.? Now guys .. I know you cant really compare a 6 element >> beam >> > to a >> > >> vertical of this kind but I am t
Re: Topband: Fw: GAP VERTICAL QUESTION
20 dB implies that the ground system loss is 10X the inverted-L radiation resistance. This would result in an input resistance of 250 ohms and a minimum VSWR if 5:1. I don't think that is what the real deal will deliver, do you? Dave WX7G On Dec 12, 2012 12:54 PM, "Guy Olinger K2AV" wrote: > With the following caveat: The very sparse and short buried radial systems > he is showing are FAR more lossy in practice than shown in his gain tables. > Four twenty foot buried radials beneath a 1/4 wave L on 160, could place > you down 20 dB. You really can't do that as your 160 meter counter poise > and expect decent results. You can end feed the same wire on 80/40/30 > meters (full wave worth of wire in the L on 80m) with four buried 20 foot > radials and it will be an excellent antenna. This is due to the high Z > feed at the ground with current max AWAY from the feed point. > > A quarter wave L on 160 MUST deal with the counterpoise loss issues, one > way or another. > > 73, Guy > > On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee >wrote: > > > This wonderful article written by L.B.Cebic W4RNL sure can make you a > > believer in a simple wire inverted L. It is the last antenna discussed. > > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf > > > > A $3 wire pulled up into a tree will beat just about any commercial > > antenna… because it is longer. So on low bands it has increased band > width > > and efficiency, and on higher bands it has gain. Yes, I know , some of > that > > high band gain is horizontally polarized, but that's not all bad. Just > get > > the vertical portion 33 feet or so and you'll be happy as Larry. The > > article shows that an extensive radial field may not be necessary. > > > > And a wire is a lot less visible than a big hunk of aluminum. Without > > trees, just top load a 43 foot (or possibly even shorter) vertical. The > top > > loading could be a T just as easily as an L. People can argue that one > all > > day. > > > > > > > > > > On Dec 12, 2012, at 11:30 AM, k6xt wrote: > > > > > My first antenna, still in use, on moving to CO is a GAP Titan, > > advertised to load up 80 thru 10 including WARC bands. The Titan is a bit > > shorter than Voyager, 28 feet or something like it. The advertising is > > correct, it loads up 180 thru 10. > > > > > > But wait. Is it effective on all those bands? No. > > > > > > On 80 its a dummy load. On 40 it works extremely well after I added a > > one foot extension to the bottom wire that encircles the antenna. In some > > cases it is the equal of my shorty HyGain 40 at 70 ft - which probably > says > > more about the HyGain than the GAP. For the rest its better on the > > traditional bands than the WARC bands. It worked a lot of DX for me for > the > > couple years it was my only antenna. > > > > > > Carrying my experience to the few feet taller Voyager, and from what > > I've been told by Voyager users, the ant will meet its spec which is to > > load up on the low bands. Expectation wise I'd expect it to be like the > > Titan. It loads up but is otherwise a dummy load. Maybe with a batch of > > radials it could be made to work as well as any other extremely short > > vertical or GP. > > > > > > Not to say there's anything wrong with GAP. My brother had up an R7 > > which he rated about like the GAP on bands both cover. Those multiband > > halfwave short verticals work but you get what you pay for. > > > > > > 73 Art K6XT~~ > > > Success is going from failure to failure without a loss of enthusiasm. > > > ARRL, GMCC, CW OPS, NAQCC > > > ARRL TA > > > > > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: > > >> With the prospect of downsizing and moving into senior housing in the > > future > > >> I am starting to look at vertical antennas that will allow me to > > continue > > >> this wonderful hobby.? I have heard "some" good things about the GAP > > series > > >> of antennas but the company says they do not need radials on most of > > them > > >> and that worries me.? Over the years I have become very skeptical > about > > >> claims and the other BS put out by most companies ( maybe it is a > > function > > >> of age I dunno) so I wonder if these antennas really work.? The two > > antennas > > >> that I am interested are the Voyager DX for 160/80/40? and the Eagle > DX > > for > > >> the rest of the bands. > > >> > > >> So my question is does anyone have actual experience with these > > antennas > > >> (especially the voyager) as compared to other antennas for a specific > > >> frequency.? Now guys .. I know you cant really compare a 6 element > beam > > to a > > >> vertical of this kind but I am talking about a comparison that is > > >> realistic.. like how does it hear, tune, match & get out compared to > > >> something like another vertical or a dipole up some reasonable > distance. > > >> > > >> I sure hope this has not opend another can of worms.. some how I seem > > to do > > >> that .. private emails
Re: Topband: Fw: GAP VERTICAL QUESTION
The question is not "How would you set up a contest station?"… it is "What is practical to keep on air in a Senior Living situation?" Now if you have a bunch of grand kids you can talk into installing radials all the better. Or if you have a fence along which you could install an elevated counterpoise all the better. But my central contention is that wire is going to outperform a GAP below 40 meters. On Dec 12, 2012, at 12:54 PM, Guy Olinger K2AV wrote: > With the following caveat: The very sparse and short buried radial systems > he is showing are FAR more lossy in practice than shown in his gain tables. > Four twenty foot buried radials beneath a 1/4 wave L on 160, could place you > down 20 dB. You really can't do that as your 160 meter counter poise and > expect decent results. You can end feed the same wire on 80/40/30 meters > (full wave worth of wire in the L on 80m) with four buried 20 foot radials > and it will be an excellent antenna. This is due to the high Z feed at the > ground with current max AWAY from the feed point. > > A quarter wave L on 160 MUST deal with the counterpoise loss issues, one way > or another. > > 73, Guy > > On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee wrote: > This wonderful article written by L.B.Cebic W4RNL sure can make you a > believer in a simple wire inverted L. It is the last antenna discussed. > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf > > A $3 wire pulled up into a tree will beat just about any commercial antenna… > because it is longer. So on low bands it has increased band width and > efficiency, and on higher bands it has gain. Yes, I know , some of that high > band gain is horizontally polarized, but that's not all bad. Just get the > vertical portion 33 feet or so and you'll be happy as Larry. The article > shows that an extensive radial field may not be necessary. > > And a wire is a lot less visible than a big hunk of aluminum. Without trees, > just top load a 43 foot (or possibly even shorter) vertical. The top loading > could be a T just as easily as an L. People can argue that one all day. > > > > > On Dec 12, 2012, at 11:30 AM, k6xt wrote: > > > My first antenna, still in use, on moving to CO is a GAP Titan, advertised > > to load up 80 thru 10 including WARC bands. The Titan is a bit shorter than > > Voyager, 28 feet or something like it. The advertising is correct, it loads > > up 180 thru 10. > > > > But wait. Is it effective on all those bands? No. > > > > On 80 its a dummy load. On 40 it works extremely well after I added a one > > foot extension to the bottom wire that encircles the antenna. In some cases > > it is the equal of my shorty HyGain 40 at 70 ft - which probably says more > > about the HyGain than the GAP. For the rest its better on the traditional > > bands than the WARC bands. It worked a lot of DX for me for the couple > > years it was my only antenna. > > > > Carrying my experience to the few feet taller Voyager, and from what I've > > been told by Voyager users, the ant will meet its spec which is to load up > > on the low bands. Expectation wise I'd expect it to be like the Titan. It > > loads up but is otherwise a dummy load. Maybe with a batch of radials it > > could be made to work as well as any other extremely short vertical or GP. > > > > Not to say there's anything wrong with GAP. My brother had up an R7 which > > he rated about like the GAP on bands both cover. Those multiband halfwave > > short verticals work but you get what you pay for. > > > > 73 Art K6XT~~ > > Success is going from failure to failure without a loss of enthusiasm. > > ARRL, GMCC, CW OPS, NAQCC > > ARRL TA > > > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: > >> With the prospect of downsizing and moving into senior housing in the > >> future > >> I am starting to look at vertical antennas that will allow me to continue > >> this wonderful hobby.? I have heard "some" good things about the GAP series > >> of antennas but the company says they do not need radials on most of them > >> and that worries me.? Over the years I have become very skeptical about > >> claims and the other BS put out by most companies ( maybe it is a function > >> of age I dunno) so I wonder if these antennas really work.? The two > >> antennas > >> that I am interested are the Voyager DX for 160/80/40? and the Eagle DX for > >> the rest of the bands. > >> > >> So my question is does anyone have actual experience with these > >> antennas > >> (especially the voyager) as compared to other antennas for a specific > >> frequency.? Now guys .. I know you cant really compare a 6 element beam to > >> a > >> vertical of this kind but I am talking about a comparison that is > >> realistic.. like how does it hear, tune, match & get out compared to > >> something like another vertical or a dipole up some reasonable distance. > >> > >> I sure hope this has not opend another can o
Re: Topband: Fw: GAP VERTICAL QUESTION
With the following caveat: The very sparse and short buried radial systems he is showing are FAR more lossy in practice than shown in his gain tables. Four twenty foot buried radials beneath a 1/4 wave L on 160, could place you down 20 dB. You really can't do that as your 160 meter counter poise and expect decent results. You can end feed the same wire on 80/40/30 meters (full wave worth of wire in the L on 80m) with four buried 20 foot radials and it will be an excellent antenna. This is due to the high Z feed at the ground with current max AWAY from the feed point. A quarter wave L on 160 MUST deal with the counterpoise loss issues, one way or another. 73, Guy On Wed, Dec 12, 2012 at 2:07 PM, Ashton Lee wrote: > This wonderful article written by L.B.Cebic W4RNL sure can make you a > believer in a simple wire inverted L. It is the last antenna discussed. > http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf > > A $3 wire pulled up into a tree will beat just about any commercial > antenna… because it is longer. So on low bands it has increased band width > and efficiency, and on higher bands it has gain. Yes, I know , some of that > high band gain is horizontally polarized, but that's not all bad. Just get > the vertical portion 33 feet or so and you'll be happy as Larry. The > article shows that an extensive radial field may not be necessary. > > And a wire is a lot less visible than a big hunk of aluminum. Without > trees, just top load a 43 foot (or possibly even shorter) vertical. The top > loading could be a T just as easily as an L. People can argue that one all > day. > > > > > On Dec 12, 2012, at 11:30 AM, k6xt wrote: > > > My first antenna, still in use, on moving to CO is a GAP Titan, > advertised to load up 80 thru 10 including WARC bands. The Titan is a bit > shorter than Voyager, 28 feet or something like it. The advertising is > correct, it loads up 180 thru 10. > > > > But wait. Is it effective on all those bands? No. > > > > On 80 its a dummy load. On 40 it works extremely well after I added a > one foot extension to the bottom wire that encircles the antenna. In some > cases it is the equal of my shorty HyGain 40 at 70 ft - which probably says > more about the HyGain than the GAP. For the rest its better on the > traditional bands than the WARC bands. It worked a lot of DX for me for the > couple years it was my only antenna. > > > > Carrying my experience to the few feet taller Voyager, and from what > I've been told by Voyager users, the ant will meet its spec which is to > load up on the low bands. Expectation wise I'd expect it to be like the > Titan. It loads up but is otherwise a dummy load. Maybe with a batch of > radials it could be made to work as well as any other extremely short > vertical or GP. > > > > Not to say there's anything wrong with GAP. My brother had up an R7 > which he rated about like the GAP on bands both cover. Those multiband > halfwave short verticals work but you get what you pay for. > > > > 73 Art K6XT~~ > > Success is going from failure to failure without a loss of enthusiasm. > > ARRL, GMCC, CW OPS, NAQCC > > ARRL TA > > > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: > >> With the prospect of downsizing and moving into senior housing in the > future > >> I am starting to look at vertical antennas that will allow me to > continue > >> this wonderful hobby.? I have heard "some" good things about the GAP > series > >> of antennas but the company says they do not need radials on most of > them > >> and that worries me.? Over the years I have become very skeptical about > >> claims and the other BS put out by most companies ( maybe it is a > function > >> of age I dunno) so I wonder if these antennas really work.? The two > antennas > >> that I am interested are the Voyager DX for 160/80/40? and the Eagle DX > for > >> the rest of the bands. > >> > >> So my question is does anyone have actual experience with these > antennas > >> (especially the voyager) as compared to other antennas for a specific > >> frequency.? Now guys .. I know you cant really compare a 6 element beam > to a > >> vertical of this kind but I am talking about a comparison that is > >> realistic.. like how does it hear, tune, match & get out compared to > >> something like another vertical or a dipole up some reasonable distance. > >> > >> I sure hope this has not opend another can of worms.. some how I seem > to do > >> that .. private emails are ok..especially it the topic gets out of hand > and > >> we get a large volume of comments (Tree please dont shoot me before > >> Christmas my wife will miss me.) > > > > ___ > > Topband reflector - topband@contesting.com > > > > ___ > Topband reflector - topband@contesting.com > ___ Topband reflector - topband@contesting.com
Re: Topband: Fw: GAP VERTICAL QUESTION
This wonderful article written by L.B.Cebic W4RNL sure can make you a believer in a simple wire inverted L. It is the last antenna discussed. http://www.users.on.net/~bcr/files/backyard%20wire%20antennaes.pdf A $3 wire pulled up into a tree will beat just about any commercial antenna… because it is longer. So on low bands it has increased band width and efficiency, and on higher bands it has gain. Yes, I know , some of that high band gain is horizontally polarized, but that's not all bad. Just get the vertical portion 33 feet or so and you'll be happy as Larry. The article shows that an extensive radial field may not be necessary. And a wire is a lot less visible than a big hunk of aluminum. Without trees, just top load a 43 foot (or possibly even shorter) vertical. The top loading could be a T just as easily as an L. People can argue that one all day. On Dec 12, 2012, at 11:30 AM, k6xt wrote: > My first antenna, still in use, on moving to CO is a GAP Titan, advertised to > load up 80 thru 10 including WARC bands. The Titan is a bit shorter than > Voyager, 28 feet or something like it. The advertising is correct, it loads > up 180 thru 10. > > But wait. Is it effective on all those bands? No. > > On 80 its a dummy load. On 40 it works extremely well after I added a one > foot extension to the bottom wire that encircles the antenna. In some cases > it is the equal of my shorty HyGain 40 at 70 ft - which probably says more > about the HyGain than the GAP. For the rest its better on the traditional > bands than the WARC bands. It worked a lot of DX for me for the couple years > it was my only antenna. > > Carrying my experience to the few feet taller Voyager, and from what I've > been told by Voyager users, the ant will meet its spec which is to load up on > the low bands. Expectation wise I'd expect it to be like the Titan. It loads > up but is otherwise a dummy load. Maybe with a batch of radials it could be > made to work as well as any other extremely short vertical or GP. > > Not to say there's anything wrong with GAP. My brother had up an R7 which he > rated about like the GAP on bands both cover. Those multiband halfwave short > verticals work but you get what you pay for. > > 73 Art K6XT~~ > Success is going from failure to failure without a loss of enthusiasm. > ARRL, GMCC, CW OPS, NAQCC > ARRL TA > > On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: >> With the prospect of downsizing and moving into senior housing in the future >> I am starting to look at vertical antennas that will allow me to continue >> this wonderful hobby.? I have heard "some" good things about the GAP series >> of antennas but the company says they do not need radials on most of them >> and that worries me.? Over the years I have become very skeptical about >> claims and the other BS put out by most companies ( maybe it is a function >> of age I dunno) so I wonder if these antennas really work.? The two antennas >> that I am interested are the Voyager DX for 160/80/40? and the Eagle DX for >> the rest of the bands. >> >> So my question is does anyone have actual experience with these antennas >> (especially the voyager) as compared to other antennas for a specific >> frequency.? Now guys .. I know you cant really compare a 6 element beam to a >> vertical of this kind but I am talking about a comparison that is >> realistic.. like how does it hear, tune, match & get out compared to >> something like another vertical or a dipole up some reasonable distance. >> >> I sure hope this has not opend another can of worms.. some how I seem to do >> that .. private emails are ok..especially it the topic gets out of hand and >> we get a large volume of comments (Tree please dont shoot me before >> Christmas my wife will miss me.) > > ___ > Topband reflector - topband@contesting.com > ___ Topband reflector - topband@contesting.com
Topband: Fw: GAP VERTICAL QUESTION
My first antenna, still in use, on moving to CO is a GAP Titan, advertised to load up 80 thru 10 including WARC bands. The Titan is a bit shorter than Voyager, 28 feet or something like it. The advertising is correct, it loads up 180 thru 10. But wait. Is it effective on all those bands? No. On 80 its a dummy load. On 40 it works extremely well after I added a one foot extension to the bottom wire that encircles the antenna. In some cases it is the equal of my shorty HyGain 40 at 70 ft - which probably says more about the HyGain than the GAP. For the rest its better on the traditional bands than the WARC bands. It worked a lot of DX for me for the couple years it was my only antenna. Carrying my experience to the few feet taller Voyager, and from what I've been told by Voyager users, the ant will meet its spec which is to load up on the low bands. Expectation wise I'd expect it to be like the Titan. It loads up but is otherwise a dummy load. Maybe with a batch of radials it could be made to work as well as any other extremely short vertical or GP. Not to say there's anything wrong with GAP. My brother had up an R7 which he rated about like the GAP on bands both cover. Those multiband halfwave short verticals work but you get what you pay for. 73 Art K6XT~~ Success is going from failure to failure without a loss of enthusiasm. ARRL, GMCC, CW OPS, NAQCC ARRL TA On 12/12/2012 10:00 AM, topband-requ...@contesting.com wrote: With the prospect of downsizing and moving into senior housing in the future I am starting to look at vertical antennas that will allow me to continue this wonderful hobby.? I have heard "some" good things about the GAP series of antennas but the company says they do not need radials on most of them and that worries me.? Over the years I have become very skeptical about claims and the other BS put out by most companies ( maybe it is a function of age I dunno) so I wonder if these antennas really work.? The two antennas that I am interested are the Voyager DX for 160/80/40? and the Eagle DX for the rest of the bands. So my question is does anyone have actual experience with these antennas (especially the voyager) as compared to other antennas for a specific frequency.? Now guys .. I know you cant really compare a 6 element beam to a vertical of this kind but I am talking about a comparison that is realistic.. like how does it hear, tune, match & get out compared to something like another vertical or a dipole up some reasonable distance. I sure hope this has not opend another can of worms.. some how I seem to do that .. private emails are ok..especially it the topic gets out of hand and we get a large volume of comments (Tree please dont shoot me before Christmas my wife will miss me.) ___ Topband reflector - topband@contesting.com
Topband: Russian 160 m contest
Starting this year, RUSSIAN 160 METER CONTEST are sponsored jointly by the Radio Magazine and the Top Band DX Club. In general, new rules of the contest are close to the RUSSIAN DX CONTEST rules (exchange, scoring, QSO points, mults). Results are scored separately for the three groups: European Russia, Asiatic Russia (see WAC rules for continent definition), and the rest of the world. This year, the contest will take place on December 14, 2012, from 20 to 24 UTC, CW and SSB. There will be only MIX entries for both SO and MS (one TX) entrants. 10 minutes rule for MS stations is to be applied for mode change. Dupes are allowed in different modes. Foreign hams send RS(T) and QSO serial number starting 001. Russian hams send RS(T) and oblast ID. Points for Russian stations: QSO with a Russian station in your own continent is 2 points; QSO with a Russian station from another continent is 5 points. Points for foreign stations: QSO with a Russian station (any continent) is 10 points; QSO with your own territory is 2 points; QSO with another territory in your own continent is 3 points; QSO with another continent is 5 points. See DXCC rules for entity definition. Kaliningrad (UA2F) counts as separate DXCC entity and separate oblast for multiplier, and as EU Russia for QSO points. Total multiplier for all entrants is a sum of entities (DXCC list), plus Russian oblast number. Each entity and oblast count once only, regardless mode. Logs shall be sent in Cabrillo format. Log-file shall be named as YOUR_CALL.log, or YOUR_CALL.cbr. Your call shall be shown in subject line of the message. Log shall be attached to the message and sent to cont...@radio.ru or downloaded via WEB interface at http://ua9qcq.com/contests/robot.php . Paper logs will still be accepted in 2012. These shall be sent to: Radio Magazine, Seliverstov Pereulok 10, Moscow, 107045, Russia. You can use RDXC logging program in this contest; just replace contest name in the log file with RADIO-160. Logs shall be sent until December 30, 2012 (including). Winners in groups shall be awarded with commemorative prizes. 2nd and 3rd winners will be awarded with RADIO Magazine Contest certificates. Complete rules of the contest may be found at ftp://ftp.radio.ru/pub/2012/11/55.pdf See English version at http://www.radio.ru/cq/contest/rule-results/index2012.shtml Everybody is welcome for the Contest! 73! -- С уважением, Vlad / R7LV mailto:r...@dx.ru ___ Topband reflector - topband@contesting.com
Re: Topband: 2011 Stew Perry Plaques
The plaques are very nice. My plaque arrived earlier this week. Really looking forward participating in this year's event. Gregg W6IZT -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Steven Raas Sent: Wednesday, December 12, 2012 1:32 AM To: topband@contesting.com Subject: Re: Topband: 2011 Stew Perry Plaques I'de like to make an addition to this post of mine, and Thank N0TT - Charles for the Youngest op with 100+ QSO's award , that Plaque arrived today, & another very deep thank you for the organizers & all whom took part. I'm really going to try and be on this year, its just been very hectic with the non-radio stuff, and minor Murphy visits. 73 to all and great TBDX tu -Steve Raas N2JDQ On Tue, Dec 11, 2012 at 7:41 AM, Steven Raas wrote: > I just rcvd one of these beauties in the mail, they look great. A big > thank you to Lew W7EW, Bob AA6VB ( Donor ), & every one that was > patient in working my Lil Pistol signal last running of this fine > event. With luck, I'll be on again this year too, but Murphy may get > the upper hand. > > 73's Everyone > Steve Raas > N2JDQ > ___ > Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
