Mods to improve Corsair transmit and receive audio: http://www.qsl.net/n1eu/Mods/Corsairaudiomod.htm I did only part of these -- put in the INRAD 2.8 kHz filter, with a bypass in one position of the second IF filters. This greatly improved transmit and receive audio and was dead simple to do. When I need more selectivity, I switch in the 2.4 kHz filter in the second IF. I highly recommend doing this modification. If you do a Google search on Ten-Tec Corsair modifications you'll find other sites. For example: http://home.planet.nl/~fhvgeerligs/Mods/Corsair/corsair.htm http://www.qsl.net/tentec/mods/560if.htm And others. I've done none of these and can't vouch for them. The Corsair AGC is bothersome. If you find a modification that improves the AGC, please post it to the reflector. A VFO rebuild wasn't necessary in my radio. Jon, K6JEK