[Premium-Rx] WJ-34903-2 HF Dual Loop for OFAS

[Stephous]

For those who are interested I took pictures of my WJ-34903-2 HF Dual Loop.
I can email them to anyone who is interested in seeing what one looks like
inside and out. I also have a -1 that I'm restoring. I intend to put both
antennas into service as time permits.

The WJ-34903 is an extremely compact drum (16" tall x 13" diameter). They
were used in harsh environments and connectors often suffered. Salt often
built up in the internal BNC fittings. The primary mission of OFAS (Overseas
Flight Assistance Service) was to establish temporary HF control areas for
medical flights. The user could drop the compact antennas in quickly and
create a CP.

 There were three versions made:
-1: Receive / Receive
-2: Receive / Transmit
-3: Transmit / Transmit

The -2 has a directional coupler and heavy field by pass to keep the
transmitted signal out of the receiving path. The receive amplifier is
turned off during transmit. The effective T/R range was 2 to 12 MHz. The
transmitter / receiver pairs could be almost any USB commercial type. I'm
guessing that the maximum transmit power was < 150W PEP.

The antenna physically consists of 2 pairs of bar antennas phased at 90
degrees, Baluns, Quad Directional Coupler, 10 db receive amplifier, and a
PVC case. The amplifier runs on +15VDC and is connected to the power source
by a locking weather proof Bendix connector. Two N connectors provide
separate receive and transmit paths. All hardware is either stainless steel
or gold plated.

Best Regards,
Steve