[hpsdr] TR isolation

[Ken]

>>I can measure -15dbm on 80M up to +10dbm on 10M coming from the PA

I looked up the relays that are on the Alex board - they have 55-60 dB of isolation on HF, if everything is just right.
With other impedances than they used for the test, it could easily be 40 dB. I sometimes work people on the "wrong" UHF band through 2 open relays in my transverter switch.

100 w out is +50 dBm 
If you wanted to keep the radio down to -15 dBm you need 65 dB isolation so I think some people might run into this problem with the Alex board when it comes out - I guess it could be solved by switching in the attenuator (30 dB) automatically when ever you went to transmit - under software control of course.

Ken
KE2N

PS - I am interested in the Alex; can you remind me out how to sign up for that?
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