[Elecraft] OT: Advice re: blocking RF from rx-only antenna

[David Herring]

Well, these certainly are compelling solutions, even though they are designed for separate transmitter and receiver, rather than separate transmit & receive antennas.  I suppose one could just "use it backwards" so to speak, and it would work.  More money than I'd hoped to pay, but not out of the question.  Not a bad suggestion really, and I'm not sure how I missed these when I was searching.

Thing that I find myself wondering now is what would happen when the receive coax gets shorted to ground, as both these units do when in transmit mode...probably nothing, but that's a question for the antenna manufacturer. 

Thanks, 73 & Aloha,

Dave, AH6TD


On Apr 22, 2012, at 10:11 AM, amsctalx at comcast.net wrote:

> I used, until recently, a ELAD transmit/receiver switch to protect the front end of my auxiliary receiver. I know that MFJ makes at one model as well (MFJ-1708), perhaps two. The ELAD switch isn't normally available in the US, but is frequently available used and can be ordered from Europe.
> 
> 73,
> 
> Mike Alexander - N8MSA
> 
> amsctalx at comcast.net
> 
> From: "David Herring" <dave at ah6td.com>
> To: elecraft at mailman.qth.net
> Sent: Sunday, April 22, 2012 4:03:14 PM
> Subject: [Elecraft] OT: Advice re: blocking RF from rx-only antenna
> 
> Hi Everyone,
> 
> Yes, this is off-topic a bit, but I know there are some of you here who will be able to get me going in the right direction.
> 
> I have a PixelSatRadio RF Pro 1A receive-only moebius loop antenna.  It is being used with a Kenwood TS-440S that does not have the provisions for a receive antenna like the K3 does.  In order to make sure one doesn't fry the antenna's pre-amp, I need a fool-proof way to ensure that no one ever accidentally sends RF down the coax to that antenna.
> 
> I have thought about maybe some kind of a PTT enabled antenna switch.
> 
> I have thought about some kind black box with a circuit one could build that would act as a gatekeeper to allow RF in from the antenna but block any going out.
> 
> I have searched the 'net and have not yet found anything along those lines that I could implement.
> 
> So my question to you is, can anyone here recommend such a switch or such a black box circuit?  Or maybe propose something else that I'm not even thinking of?  Any ideas, suggestions, recommendations?  
> 
> 
> 
> I need this to be on-the-cheap and I'm not opposed to homebrewing something here, though I only have modest-at-best skills in homebrewing.
> 
> 
> Many many thanks,
> 
> Dave, AH6TD
> 
> 
> I now return this reflector to normal programming, already in progress.  ;-)
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