Val 760 TSO Receive problem

I installed my 760 Val in my RV6 and could not get any reception. The FBO said he could hear the transmission clearly. I can hear the squelch when I check it so I reasoned it was not a headset or wiring issue. Sent the radio to Val to get checked out, they said there was nothing wrong with it and sent it back. I wanted to make sure it was not an intercom issue so I wired the jacks directly to the comm bypassing the intercom. Made sure jacks were isolated from the panel and all wires were correct. Tuned in the local AWOS and could not hear anything unless the squelch knob as pulled out. I am ready to test fly my RV6 after a major rebuild, but not without communications. Any suggestions on what to try next?

JKearns
Kearns Metal Works
N35K

Please do keep in mind that transmitting and receiving are two very different animals. Just because you've managed to get somebody nearby to indicate they are receiving your transmitted signal doesn't mean the antenna and coax are good.

The transmit signal is HUGE in comparison to the receive signal, thus you can squander a whole bunch of transmit energy in a bad antenna or coax cable and it won't make any difference to the guy receiving you a half mile away across the airport. Squander the same proportion of received signal and your poor radio receiver is left straining to hear a very faint signal indeed.

With this in mind, and since you've done a major rebuild, I'd be yanking the antenna off and giving a really good cleaning to its mounting location and hardware, buffing up the exterior of the BNC connector on the antenna, and then taking a long hard look at that coax cable. If it's old enough that you've rebuilt the airplane, you might want to consider removing the old (probably black RG-58) cable and installing new RG-400 cable.