[Kenwood] 742 fading xmit audio

[Tom WA9WSJ]

Hello Gents,

The two meter module in my 742 has fading transmit audio when in high power.

It had this once before and I found that the pin diode D15 was bad. No so this time. I changed the S-AV17 output module but that wasn't it either.

The unit does this when it gets HOT. But even when hot, switching to medium power right away cures the problem. 

There is no problem with the power supply, it is supplying sufficient power.

Any ideas on this one?

Thanks!

Tom WA9WSJ