[Amps] 800H questions

[Dinsterdog@aol.com]

I have a Ameritron 800H that I am having some problems with power output.  I 
called Ameritron this week and they helped a lot, but still not sure if my 
amp is ill.  

The problem Ameritron ID'd was that my line voltage was down.  It was showing 
a HV of 2,400V going down to 2,100V when transmitting. So they suggested I 
redo the transformer taps so that I set the amp for the highest line voltage 
at 230V vs the factory setting at 240 volts.  This worked very well and my HV 
went up to almost 2,700V going down to 2,400V when transmitting. It increased 
my over-all average power from 1,300W to 1,750W.  

But I still need the IC756Pro to drive the amp with 110 watts to get this 
power and after about 30 seconds of pulse keying, the average power decreases 
down to about 1,400 watts. .  At 65 watts of drive, I'm only averaging about 
1 KW out but I don't see a power drop using pulse keying at this decreased 
drive level. 

Can anyone suggest anything else I can trouble shoot to get the amp to put 
out a steady 1.5KW with less drive vs what I'm having to drive it with now?  
Is this a tube issue?  The tubes are only 2 years old-  Also, when I turn the 
amp on, I hear a sizzling sound for a few seconds.........any chance that my 
over all problems are related to a troubled transformer/power supply??  
Should I cut my losses now and just find a new amp or is there something 
obviously ablaze here? 

73 Paul  N0AH