-------->> ex : F6EUQ / 74 .............................................ICW............................................

Saturday, September 21, 2013

5/10KW ANTENNA COUPLER

My QRO ANTENNA COUPLER – (Z ANTENNA COUPLER).
Built in 2006 on the BBQ bench, I decided to rebuilt it today.
This coupler can work up to 15 KW SSB output from 160 m up to 10 m.
I included an integrated Bird Thruline® 7/8" Line Section wattmeter two sockets Plug-In Elements, with IN/OUT 7/16 connectors to indicates the forward and reflected transmission power,  for quick and accurate adjustment of the antenna. Tested on professional amplifier's site with 10 KW HF Amplifier  Marconi H1140 and  HF Amplifier ELCOR SW-20K



Usually, I don't like to use an antenna coupler, but I wanted to cover all HF bands (lower to upper), including WARC, and no other choice to go through a coupler.
Then, in 2006 in 9Q land (DR Congo), I built a Pi and I decided now to change with a T antenna coupler.
To be used with a 8 el. log periodic antenna (recover in a Kinshasa Embassy, (prob was observed as no linearity from 10 to 30 MHz) also for a 1,8 Mhz long wire INVERTED L 3/4 lambda with my OM2500 PA.
I was lucky to find a couple of vacuum CV in an old broadcast HF transmitter. The major problem was that these CVs have the adjustment not by rotation but by extension. How to solve it? Not easy, but I had to adapt in the 9Q land with spares parts of gearbox car !!!! with a system of rotary screw and nut fixed on the axis of the CV. Also rotary counters removed form old tape recorder.. CV support and coupling made with 1cm thick Green Teflon PTFE.

A little big, yes! But the main thing was that I could work with these CV. I used this system for more of 30.000 QSO.
Over a long period, I managed to accumulate the necessary parts to rebuild it and I found, couple of parts as dial vacuum CV.
Two models, one from Russian surplus and the other VIC as a copy of Jennings .
 CVDD-1000-15S   (25 to 1000 pF)  and CVDP 2300-15S (50 to 2300 pF)
I had to adapt the Russian model for fixing, but I preferred to use the VIC model.
I also found some vacuum relays as B2B, RJ2B-26S  and Roller Inductor in Auxerre France, Hamfest.
For the time being, I don't use the balanced antennas, I omitted  to install the balanced output in the coupler and I do not plan to spend a two-wire line in the shack. If I will use it one day, the balun will be outside the shack with a ladder line to the antenna.
So, except to find a way to make or find the shaft insulated coupling, the rest is only a matter of assembly.
So far, so good....I managed to match any combination with some antennas that I needed for max tune.
- 3 x 10 kw HF Amplifier  Marconi H1140

 
Some Pics in 2006..