[TowerTalk] 2x2 High Power Antenna Relay Boxes

jimlux jimlux at earthlink.net
Mon Jun 10 19:17:09 EDT 2019

On 6/10/19 4:02 PM, Jim Brown wrote:
> I need to trade flip two antennas between two radios. The only 
> commercial product I see is a Transco box sold by Array Solutions. Is 
> that the only choice? The application is legal limit on 80M.

at 4MHz, maybe a "reversing switch" might work for you? For large motors 
and such. Also known as a "transfer switch",  Also known as a "baseball 
switch" in waveguide, there's two basic designs - one is a conventional 
DPDT relay kind of thing where the NC and NO contacts are cross wired. 
The other has a rotating plug with two shorting bars and the "spigots" 
go "Tx 1", "ant 1", "Tx 2", "Ant 2" around the plug, which rotates 90 

The advantage of this over a conventional SPST or SPDT "relay box" is 
that it's a single device, so you don't have the "accidentally short 
transmitters together" problem.

I am sure there are (exceedingly) pricey units that do this from DowKey, 

There's a whole lore on building "safe" microwave switching networks 
with N transmitters and M antennas and L receivers with these things.

- it will take 8 kW @ 100 MHz with the right connectors...

There's a Transco on Ebay for $75 with some connector that sort of looks 
like an N, but not quite (insulating conical center conductor)

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