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

[Mark Donaldson]

Steve,

I would like to see those pictures you took of the WJ antenna.

73s

Mark WA1QHQ


--- On Wed, 9/10/08, Stephous <stephous at att.net> wrote:

> From: Stephous <stephous at att.net>
> Subject: [Premium-Rx] WJ-34903-2 HF Dual Loop for OFAS
> To: premium-rx at mailman.qth.net
> Date: Wednesday, September 10, 2008, 6:30 PM
> 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
> 
> 
> 
> 
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