[TMC] another TMC station on the air! Tube tester?

[H A Layer]

Nick:

Congratulations!  That is great news.  TMC forever!

If possible, how about a photo portrait of you with microphone next to 
this classic TMC beast?

My latest news is a bit sad.  My PAL-500 linear amplifier has become 
anemic and I am not sure why--probably one (or both)
of  the PA tubes (4CX350A) has gone flat.  On 75m, I now can achieve no 
more than 50W carrier at 300mA plate current.

Also, with a dummy load, I just tried to determine the optimum PA 
tuning/loading settings for each ham band.
Only 75m worked.  On 15m, these controls did nothing at any setting, and 
all of a sudden, I heard a big "bang"
in the power supply, and the HV line switch flipped to off position by 
itself (safety feature?).  With fingers crossed
I reset everything to 75m, and turned it back on.  Everything 
works--apparently no damage.  But, still anemic--and
now restricted to 75 meters!

I wish there were a way of adapting a standard tube tester to check 
these tubes.  It would be easy to construct
an outboard tube socket and patch to the tester's octal socket. the 
grid, cathode, and plate connections.
Filament voltage would be supplied only to the outboard socket by an 
outboard filament transformer that can
handle 6.0V at 2.9A. And the tube tester could be set for testing a 
heavy-duty tube, such as a 6146.  The readings
would be arbitrary, but useful in comparing new and old tubes.

73 Hal KK6HY

P.S. I successfully used the small FLEX-1500 as a one-watt exciter for 
the PAL-500.  Very good audio reports!