Author: Rudy Bakalov via TowerTalk <towertalk@contesting.com>
Date: Thu, 31 Aug 2017 18:22:05 +0000 (UTC)
Hi folks, I am building my 80m 4SQ. The elements are made of wire attached to 8' poles and then raised radials also about 8' above the ground. While tuning the verticals we observed an unexpected beh
Author: Rudy Bakalov via TowerTalk <towertalk@contesting.com>
Date: Thu, 31 Aug 2017 21:23:25 +0000 (UTC)
I am measuring the impedance at the very base of the vertical with a calibrated RigExpert. According to DX Engineering the vertical should be connected without any baluns, matching networks...nothing
Author: Rudy Bakalov via TowerTalk <towertalk@contesting.com>
Date: Thu, 31 Aug 2017 23:45:40 +0000 (UTC)
This is becoming a troubleshooting exercise now. I tuned all verticals to around 3,413. Each vertical has a 70' element and 68.5' single radial about 7' above the ground. RigExpert measures SWR aroun
What is the reason for making the verticals 4% long? I am far from being a 4sq guru however it would seem that you should have a choke, especially with an elevated feedpoint. It is easy to make one u
My understanding is the mutual coupling between the four 1/4 wavelength verticals tends to raise the resonant frequency by ~ 5%, (that is what I have read in numerous places), meaning that you want t
Rudy, It sounds as though you are tuning the verticals while they are coupled in the array. I always tune the individual elements in an isolated environment. Then pull up the whole array to see how i
Author: Rudy Bakalov via TowerTalk <towertalk@contesting.com>
Date: Fri, 1 Sep 2017 12:38:35 +0000 (UTC)
First and foremost thank you everybody who took the time to read my post and provide thoughtful suggestions and additional references. I also realize, based on some of the comments, that I have not f
Author: Rudy Bakalov via TowerTalk <towertalk@contesting.com>
Date: Fri, 1 Sep 2017 15:00:57 +0000 (UTC)
Correction, 70' radial and 68.5' element. Good catch! Rudy N2WQ On Friday, September 1, 2017, 10:16:24 AM EDT, Bryon Paul Veal NĜAH <bryonveal@msn.com> wrote: guys, is it jist me or do these antennas
You might like my article on a recent rebuild of the 80m wire 4sq at N6RO in the July/Aug 2017 issue of NCJ, or download it from: http://www.wb9jps.com/Gary_Johnson/Amateur_Radio_files/Four_Square_Re
your seeing changes in the FEEDPOINT impedance using a tuned raised radial, thus your SWR will move if yoy mess with them. Suggest you consider using UnUns at the feedpoints to match the coax impeden
this is why I prefer a comtek hybred coupler.....I would suggest you look into one. You will use 75 ohm coax due to velocity factors but any RF feeding back due to SWR is burned off in a dummy load.
but with a comtek hybred coupler, you will never care aboit that 3%....plus the skin effect of wet radiators cause much bigger resonant changes that again, the hybred couplers dummy load soaks up....
guys, is it jist me or do these antennas sound to long to begin with? Array resonant aside... Sent with AquaMail for Android http://www.aqua-mail.com This is becoming a troubleshooting exercise now.
Author: Dan Maguire via TowerTalk <towertalk@contesting.com>
Date: Sat, 2 Sep 2017 06:36:19 +0000 (UTC)
This is what a model of N2WQ's 4-sq might look like, with each of the four elements in the shape of an "L" (68.5 ft vertical, ~70 ft horizontal) and with a 90 ft grounded tower in the center. https:/
No, that is not correct and both of my 4-squares use the Comtek Hybrid. Of course I care about 3% at 3.5 mhz, that 3% changes the resonant freq. of the array (and minimum dumped power to the dissipat
Dans simulations and observations are spot-on as usual. So... 1. For the complete system, observe dump power vs. freq rather than SWR. 2. Frequency shift between resonance of a free element vs. that
When I first put up my array, I only cared about the CW window, and again, used bottom fed coils with and alligator clip to go from the PH band to the CW band after some revisions. I agree with Bob t
I never have heard of a successful array using raised radials ... so this has been a good exercise. Also strongly agree with tuning the verticals to the intended frequency ..... but this is all with
Dan and Gary are two fine engineers, and, as usual, their work is excellent. Gary's work was careful to study each element of the array alone, with the other elements open circuit to minimize couplin
Author: Dan Maguire via TowerTalk <towertalk@contesting.com>
Date: Mon, 4 Sep 2017 06:19:05 +0000 (UTC)
I spent some time with that question. From the DXE Transmit Four Square System (DXE-TFS4-80B) manual: "Set the resonance to the low edge of your desired operating range. This is because array perform