Question on TX/RX antenna ports [1 Attachment]

John Lloyd <lloyd@...>

Hi Jim,

Remember that you should also install a low pass filter or band pass cavity after the isolator to keep it off the antenna for IM reasons.

John Lloyd, K7JL

Jim Kusznir wrote:

Ack, this message got mis-filed by my mail client, sorry for the delay!

Here's my attempt at a block diagram...I'm pretty poor at diagramming...

This is what my current Mitrek on the hill is configured as. Simple intercept of the TX line to the TX/RX switch. It breaks that out externally for isolator support, then brings it back into the box and uses the stock TX/RX relay for switching.

For my purposes, it would be great if I could get a "standard" UDR, except there are two additional connectors on it (SMA is fine :) ), that breaks out the TX path (and if desired, the radio can ship with a jumper across these two ports such that it functions identically to a stock UDR). For those users who want to use seperate TX and RX antennas, I think they could just use the TX out and not send it back into the radio for their TX output, and use the "normal" antenna port for RX. That way the receiver is still protected against too much RF on transmit.

Anyway, thanks for your response! My Mitrek on the hill isn't doing so well now, so I'm leaning more and more toward replacing it with a UDR as soon as I can get one (originally I was just going to get one for personal use).

On Tue, Jan 28, 2014 at 1:31 PM, <bhhoyer@... <mailto:bhhoyer@...>> wrote:


I reviewed our setup and it requires an external switch to protect
the receive port and yes the Tx/Rx signal is available to drive it.

Please send me a block diagram of the application. I may be able
to make a slight change and use the internal switch.