I have a problem with my IC-738. I will try to describe it as best as I can. I have found NOTHING related to this problem ANYWHERE on the web.
After transmitting, for instance either blipping the morse key or softly blowing into the mike (in SSB), after unkeying I get a weird noise in the RX audio. To make the noise go away I just softly and quickly blow into the mike again, or blip the key. Merely keying the mike and unkeying won't work to cause the problem or make it go away UNLESS it's in AM mode.
The problem only occurs (or is audible) on the entire 40 meter band. It is a buzzing noise that registers on the S meter at a solid S9 in USB and LSB. It does not drown out the white noise completely, and signals stronger than S9 can still be heard. The noise is present on AM mode also, at S9+10. In FM mode, the noise is not there but the S meter goes to +20, and drops back to...a lower value after keying the mike 1 or 2 times.
I have tried different patch cables, antennas, etc. I have checked the station grounds (or at lest the mechanical integrity) and have tried different power sources. I have removed the amp from the station, changed all sorts of things and this has not affected the problem.
The only guess I've heard from others who have listened to me complain is a possible faulty changeover (RX/TX) relay, but I would expect this to affect all the bands and not require RF to cause the problem?
What do yall think?
Thanks, Tim KD0JHT