Hello N1BUG,

Just to add things were MUCH worst using a X2 multiplier circuit
(Jay's). I now use an exciter frequency of X2 direct both from the
U3S, and as of late X2 from the TS-590 into a simple squarer and use
WSPR in the "Advanced" X2 mode to correct the WSPR tones. No issues at
all with either. OPERA is a no no as of this time, it is a FET killer
:)  Don't  know  why though. It would be great to get to the bottom of
all this!

Tuesday, February 26, 2019, 11:05:15 AM, you wrote:

> Jay,

> I was using an HF transceiver in CW mode through a down converter.

> Other FETs were lost at end of envelope while running JT9 with the
> transceiver in USB being fed audio from a sound card. The latest was
> with audio from a different sound card into the new phasing exciter.

> I have never lost a FET while running with the U3S.

> 73,
> Paul




-- 
Best regards,
 Chris                            mailto:[email protected]