|The picture is one of a
kind. Not so much the tower... it is a Rohn HBX 56 ft. with mast
9 foot above the tower. The two antennas are A4WS on top and a
completely refurbished TH6DXX on the bottom. The TH6 has every
clamp, plastic replaced. The aluminum was cleaned and polished. The Hy-Gain Tailtwister was refurbished at the factory. The idea was to have this installation last for my lifetime.
The A4WS is another story. There is technically no such antenna and no cooperation was obtained from Cushcraft is constructing the antenna. I was in possession of two Cushcraft rotating dipoles... one was 12/17 and one was 12/17/30. I also had a never used Hy-Gain 15 meter mono-bander and a used 20 meter Hy-Gain mono which I used for 12 & 17 meters. If you are familiar with Cushcraft antennas, you know that they made a A3 and A4 for 10/15/20. The difference was that the A4 had separate reflectors. They also made a A3WS for 12/17 with a 30 meter add-on available. So, I copied the front half of a A3WS and have trapped driven element and trapped directors. I split the reflectors without traps and used .15 spacing as does Hy-Gain on their 12/17 beam. I asked Cushcraft for measurements but they were not willing to help. Here's what I think is unique... the antenna uses Hy-Gain boom and boom clamps... both to the mast and element to boom... however, all the traps are Cushcraft. I am calling the antenna a "A4WS" since Cushcraft never made one and didn't want to talk about it. I did tell them I would discuss this with them at Dayton. BTW, I originally had two more directors on the antenna for 12 meters but it made feedpoint matching too difficult. As you know, Cushcraft does not use a matching network... they shorten the elements to offset the reduced impedance at the feedpoint caused my interaction between elements. Measured impedance was 17.5 ohms. The SWR is 1.2 to 1 on 12 and 17 and 1.5 to 1 on 30 meters. The TH6 meets all the original factory specs.
Murphy was with us every step of the way... I made every mistake that could be made... just not thinking clearly. Thankfully N4MHQ hung in here with me and we got it done. The total cost of moving the tower, increasing height 16 ft. and refurbishing everything is not something I want to put in writing... I could have bought a good amplifier.