[Elecraft] XV432 low output power

[Steve Bunting]

Hi Folks,

I wonder if I can pick the collective brain about my XV432 which has low 
power output.

I am driving the transverter with my K2 and the XV60. This is all fine 
as my XV144 performs perfectly. The problem is in my XV432.  Key down I 
get about 7W output for the first second or so then as they key is held 
down the output drops along a pseudo logarithmic curve. The K2 indicates 
that the drive power is falling (this does not happen with my XV144).

The typical voltages at active devices are OK (except for those which 
are cited for 20W output of course). The RX side seems OK, but I don't 
really have any serious test gear to run it against.

R22, the input attenuator is fully CW, i.e. least attenuation. This 
suggests that there is not enough drive, but the tx voltage at output 
pin of U6 is fine. Could I have I partially toasted the factory 
installed amplifier (U6 - I hope not). Perhaps the drop in output power 
could imply a filter problem?

I have checked all of the jumpers several times to see if is this an 
RTFM issue, but I am now stuck. Any suggestions?

73
Steve
M0BPQ