"Gert Been" wrote in message
...

Ehh, talking about "Decent" multiplexers: decent multiplexers have
isolated
inputs, yours don't.

I just connected one of yours to a differential NMEA talker output. I can
now hear all NMEA data on my SSB!!

While trying to find out what's wrong, I found that all inputs on your
multiplexer have the B terminals connected to ground!!! NMEA inputs are
supposed to be isolated. Your grounded B terminals on the inputs
effectively
short-circuit any properly designed talker. Was it that hard to add 50
cents
worth of optocouplers?

Ouch!!!

Meindert