Topband: Fwd: Re: Suggestion for RX Antenna control box/switching box

[Herbert Schoenbohm]

Ray,  I have found on Ebay some push button video switchers that have
both UHF and BNC connectors. One nice thing about these units, apart
from the low priced as TV station surplus throw aways, is the fact that
they all terminate in 75 ohms on every unused port. I have several 6X1,
a 3X1, and even a 12X1 unit  Some have illumination for the selected
button which is a feature I do not use. Even though they are designed
for video they have excellent isolation on 160 meters.  I bought both
rack mount units and non-rack mount boxes and use them to route and
switch the RX antennas to several units including an MFJ 1026 Noise
Cancellation box. The only drawback is that there is in shack (not in
the RX) an audible pop they make when a selection is made.  This on VOX
operation is sharp enough to trigger the VOX.  I hope that some day I
can find a similar switch that works with multiple miniature relays with
termination of unused ports. Ever better would be an on screen computer
controlled remote switch that could be mounted outside where all the
feedlines shields  are individual grounded via several 2.5 inch
toroids.  This termination is suggested since I use  two wire Beverages
and the RG-6 feedlines are cut for multiples of half waves so the
termination in the shack appears at the Beverage feed point.



Herb Schoenbohm, KV4FZ


On 10/18/2014 5:24 AM, Ray Benny wrote:
> I'm trying to figure out in my mind how to build a box that will allow me
> to select a HiZ 4 square, two beverages, an RX loop, and switch in an MFJ
> 1026 Noise Cancelling device using the listed RX antennas - to two radios
> using their external RX antenna jack. I know that I need to be concerned
> with isolation and grounding. Can I use several older ceramic rotary
> switches, relays or what?
>
> How do some of you do it? Can you share a block diagram, a schematic and
> maybe some construction notes?
>
> I appreciate your input!
>
> Ray,
> N6VR
> _________________
> Topband Reflector Archives - http://www.contesting.com/_topband