Re: Topband: What ever happened to the 160 meter "Z" antenna?
I seem to remember that ant and another person who claimed to get a goo match with a sloper fed with a i think 1/4w of wire conected at abt 2` from base of tower .I have lost them notes . I put up a vertical abt 50 ` high with top bottom capacity hats, 120` long.Now this was suspended in a tree 80` high, and with 100 watts was heard, and nearly got a contact with a US station, but he had local qrm. But worked Cape Verde Isles and the Azores as a consolation prize. thanks.. EI7BA And Mr Stevens. Roll on the first or March. 73`s G8CCL On 17 February 2015 at 12:16, Stan Stockton wrote: > A good analysis of all this can be found from IV3PRK as he planned his > antenna for his new QTH in HC land. > > http://www.iv3prk.it/user/image/site2-inverted-l-vs-vertical-t.pdf > > 73...Stan, K5GO > > Sent from my iPad > > On Feb 16, 2015, at 6:14 AM, Tom W8JI wrote: > > >> Tom, Thanks for the details on the "Z" for TB. On a related matter I > have been looking for comparisons between a "L" and a "T" firmly believing > that a "T" would be better as in 65' up and 135' horizontal fed in the > exact center. However there are so many TB'ers using "L" rather than "T"s > which begs the questionwhy? You need two supports for the "L" but how > much do you gain by converting this to a "T" with even a modest ground > plain of 6-12 radials? Or is it just a matter of convenience and lot size? > > > > There is almost no difference between the T and L. It is mostly a matter > of what someone can fit. > > > > When I lived on a city lot, I had restricted antenna room. I installed a > "G5RV" between two tall pines. I dropped the feedline vertically to the > ground. I fed the entire thing as T on 160, and I managed to work many > JA's, VU, UA0's, VS6, and even a JT on 160. An L I tried was no different, > but too many wires cluttered an area and makes an RF mess out of things. > The G5RV gave me a good 160 antenna (fed as a T) and a pretty good 80-10 > antenna, with just one wire and one feedline, using a tuner right where the > feeder came to ground level. > > > > I installed a 100 ft vertical later, and it was no better than the G5RV > "T". As a matter of fact I just phased the 100ft tower against the G5RV to > make a two element 160 vertical array with four patterns. > > > >> Again my question: How much better is a "T" over an "L" on 160? > > > > No one would notice, it is not even worth one dB. We are actually lucky > to notice 6 dB unless we A B test something. > > > > You would likely notice the out and up and out half wave, though. It is > far more like a messed up dipole than a good vertical. The one I tried > lost several dB on groundwave over a base loaded vertical. It kept getting > better and better as I made it more and more like an "inverted L". > > _ > > Topband Reflector Archives - http://www.contesting.com/_topband > _ > Topband Reflector Archives - http://www.contesting.com/_topband > _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: What ever happened to the 160 meter "Z" antenna?
A good analysis of all this can be found from IV3PRK as he planned his antenna for his new QTH in HC land. http://www.iv3prk.it/user/image/site2-inverted-l-vs-vertical-t.pdf 73...Stan, K5GO Sent from my iPad On Feb 16, 2015, at 6:14 AM, Tom W8JI wrote: >> Tom, Thanks for the details on the "Z" for TB. On a related matter I have >> been looking for comparisons between a "L" and a "T" firmly believing that a >> "T" would be better as in 65' up and 135' horizontal fed in the exact >> center. However there are so many TB'ers using "L" rather than "T"s which >> begs the questionwhy? You need two supports for the "L" but how much do >> you gain by converting this to a "T" with even a modest ground plain of 6-12 >> radials? Or is it just a matter of convenience and lot size? > > There is almost no difference between the T and L. It is mostly a matter of > what someone can fit. > > When I lived on a city lot, I had restricted antenna room. I installed a > "G5RV" between two tall pines. I dropped the feedline vertically to the > ground. I fed the entire thing as T on 160, and I managed to work many JA's, > VU, UA0's, VS6, and even a JT on 160. An L I tried was no different, but too > many wires cluttered an area and makes an RF mess out of things. The G5RV > gave me a good 160 antenna (fed as a T) and a pretty good 80-10 antenna, with > just one wire and one feedline, using a tuner right where the feeder came to > ground level. > > I installed a 100 ft vertical later, and it was no better than the G5RV "T". > As a matter of fact I just phased the 100ft tower against the G5RV to make a > two element 160 vertical array with four patterns. > >> Again my question: How much better is a "T" over an "L" on 160? > > No one would notice, it is not even worth one dB. We are actually lucky to > notice 6 dB unless we A B test something. > > You would likely notice the out and up and out half wave, though. It is far > more like a messed up dipole than a good vertical. The one I tried lost > several dB on groundwave over a base loaded vertical. It kept getting better > and better as I made it more and more like an "inverted L". > _ > Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: What ever happened to the 160 meter "Z" antenna?
Tom, Thanks for the details on the "Z" for TB. On a related matter I have been looking for comparisons between a "L" and a "T" firmly believing that a "T" would be better as in 65' up and 135' horizontal fed in the exact center. However there are so many TB'ers using "L" rather than "T"s which begs the questionwhy? You need two supports for the "L" but how much do you gain by converting this to a "T" with even a modest ground plain of 6-12 radials? Or is it just a matter of convenience and lot size? There is almost no difference between the T and L. It is mostly a matter of what someone can fit. When I lived on a city lot, I had restricted antenna room. I installed a "G5RV" between two tall pines. I dropped the feedline vertically to the ground. I fed the entire thing as T on 160, and I managed to work many JA's, VU, UA0's, VS6, and even a JT on 160. An L I tried was no different, but too many wires cluttered an area and makes an RF mess out of things. The G5RV gave me a good 160 antenna (fed as a T) and a pretty good 80-10 antenna, with just one wire and one feedline, using a tuner right where the feeder came to ground level. I installed a 100 ft vertical later, and it was no better than the G5RV "T". As a matter of fact I just phased the 100ft tower against the G5RV to make a two element 160 vertical array with four patterns. Again my question: How much better is a "T" over an "L" on 160? No one would notice, it is not even worth one dB. We are actually lucky to notice 6 dB unless we A B test something. You would likely notice the out and up and out half wave, though. It is far more like a messed up dipole than a good vertical. The one I tried lost several dB on groundwave over a base loaded vertical. It kept getting better and better as I made it more and more like an "inverted L". _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: What ever happened to the 160 meter "Z" antenna?
Tom, Thanks for the details on the "Z" for TB. On a related matter I have been looking for comparisons between a "L" and a "T" firmly believing that a "T" would be better as in 65' up and 135' horizontal fed in the exact center. However there are so many TB'ers using "L" rather than "T"s which begs the questionwhy? You need two supports for the "L" but how much do you gain by converting this to a "T" with even a modest ground plain of 6-12 radials? Or is it just a matter of convenience and lot size? Here on 80 meters I use a "T" with a 50' drop wire and a 20 foot center fed top wire. Sloping off to one side of the top is a 34' drop wire separated with some Dacron rope so the 40 meter section meets the same feed point. And this makes for a very good performing 80/40 meter vertical. At times on some DX it outperforms my 80/40 meter dipole at 70 feet. The ground system is 20 radials made from Cat 5 cable laying on the ground with the feed point and ground rod next to the the septic system tank. Again my question: How much better is a "T" over an "L" on 160? Herb Schoenbophm, KV4FZ On 2/16/2015 6:23 AM, Tom W8JI wrote: Rick, I think it had more to do with getting something out of the shack window with the tuner inside. I also think it had more to getting the current maximum at the top of the pole. The OT's used to tell me they just taped a #47 bulb and a small loop of wire at the top and fed some power 20 watts or so at night and then trimmed the far end for maximum brilliance to try and get the current maximum at the top of the slant wire. With some vertical component and horizontal cancellation I can not see how this was a *bad* antenna for beginners on TB. That was an antenna popular in the early 1960's, I tried one myself back then. It appeared everywhere as an improvement to a vertical or inverted L antenna. It was ideally out 65 horizontally, up 65 vertically, and out 130 horizontally. If the vertical section was lower height, the low horizontal was extended. The idea was to get current at the top of the vertical section, and enough length on a horizontal single wire feed to make it a 1/2 wave, but it was a bad idea. Mine was way down in signal strength locally on groundwave over a base loaded vertical. It improved greatly when turned into an inverted L with current maximum at the base. As Rick says, it acted more like a bent dipole with one end 6 feet off the ground for 70 feet or more. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: What ever happened to the 160 meter "Z" antenna?
Rick, I think it had more to do with getting something out of the shack window with the tuner inside. I also think it had more to getting the current maximum at the top of the pole. The OT's used to tell me they just taped a #47 bulb and a small loop of wire at the top and fed some power 20 watts or so at night and then trimmed the far end for maximum brilliance to try and get the current maximum at the top of the slant wire. With some vertical component and horizontal cancellation I can not see how this was a *bad* antenna for beginners on TB. That was an antenna popular in the early 1960's, I tried one myself back then. It appeared everywhere as an improvement to a vertical or inverted L antenna. It was ideally out 65 horizontally, up 65 vertically, and out 130 horizontally. If the vertical section was lower height, the low horizontal was extended. The idea was to get current at the top of the vertical section, and enough length on a horizontal single wire feed to make it a 1/2 wave, but it was a bad idea. Mine was way down in signal strength locally on groundwave over a base loaded vertical. It improved greatly when turned into an inverted L with current maximum at the base. As Rick says, it acted more like a bent dipole with one end 6 feet off the ground for 70 feet or more. 73 Tom _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: What ever happened to the 160 meter "Z" antenna?
Rick, I think it had more to do with getting something out of the shack window with the tuner inside. I also think it had more to getting the current maximum at the top of the pole. The OT's used to tell me they just taped a #47 bulb and a small loop of wire at the top and fed some power 20 watts or so at night and then trimmed the far end for maximum brilliance to try and get the current maximum at the top of the slant wire. With some vertical component and horizontal cancellation I can not see how this was a *bad* antenna for beginners on TB. Herb, KV4FZ On 2/15/2015 7:53 PM, Richard (Rick) Karlquist wrote: On 2/15/2015 3:15 PM, Herbert Schoenbohm wrote: Many years ago when topbanders were looking for better efficiency and something thart would radiate with limited space lots there was the "Z" which was essentially a way of feeding a 1/2 wave sloper from a tapped coil L/C circuit at the shack end by running the first 1/4 wave of wire close to the ground (were it was claimed to do minimum radiation since it was voltage rather than current fed) and then sloping it upward to a tree or pole with the top portion doubled back horizontal to the ground Herb Schoenbohm, KV4FZ This is a fallacy. Where you feed the antenna doesn't affect where it radiates. You would get the same results if you fed it as a bent dipole at the junction between the first 1/4 wave and the upward sloping portion. Which is to say poor results. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: What ever happened to the 160 meter "Z" antenna?
On 2/15/2015 3:15 PM, Herbert Schoenbohm wrote: Many years ago when topbanders were looking for better efficiency and something thart would radiate with limited space lots there was the "Z" which was essentially a way of feeding a 1/2 wave sloper from a tapped coil L/C circuit at the shack end by running the first 1/4 wave of wire close to the ground (were it was claimed to do minimum radiation since it was voltage rather than current fed) and then sloping it upward to a tree or pole with the top portion doubled back horizontal to the ground Herb Schoenbohm, KV4FZ This is a fallacy. Where you feed the antenna doesn't affect where it radiates. You would get the same results if you fed it as a bent dipole at the junction between the first 1/4 wave and the upward sloping portion. Which is to say poor results. Rick N6RK _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: What ever happened to the 160 meter "Z" antenna?
Many years ago when topbanders were looking for better efficiency and
something thart would radiate with limited space lots there was the "Z"
which was essentially a way of feeding a 1/2 wave sloper from a tapped
coil L/C circuit at the shack end by running the first 1/4 wave of wire
close to the ground (were it was claimed to do minimum radiation since
it was voltage rather than current fed) and then sloping it upward to a
tree or pole with the top portion doubled back horizontal to the ground
below. It has been many years since I heard of this antenna that was
supposed to minimize ground connection loss and provide some vertical
radiation (DX) component. Nor am I aware that anyone has model this
design as there were even some folded back version to save space.
Herb Schoenbohm, KV4FZ
I have modeled it and the results are predictable. About
half your power goes into likely useless horizontally
polarized radiation. If you instead make a top loaded
("T" type) vertical where the sum of the height and half
the top wire is a half wave, then you get a "voltage fed"
vertical that behaves pretty much like a half wave
vertical. Since the drive impedance is high, you MIGHT
get away with a much less extensive counterpoise.
There is some controversy about this.
Rick N6RK
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