Good advices for a newbie (threading tools lathe)

[rendoman]

bad news today

I tried to measure both first stage gain and second one. I switched between pentode and triode connection, I changed from resistor load for pentode to output transformer.

summing:

- first stage voltage amp (little triode of pcl82 tube) imput 820mV for maximum voltage gain of 50v




- output stage triode connection , imput from generator (I will measure this a 3rd probe even from first stage) max 360mV for 114v output




- output stage pentode connection , 244mV for 136v output



Clean limits, after this threshold curve become bad.

I tried also measure with output transformer and speaker - 9,1 ohm resistor ( I didin't have 8ohm at home ), output voltage is really low, under half watt in "clean" curve, I settled tek scope to ch1-2 rms voltage. Anode voltage is 310v, I'm thinking about something happened to catode resistor. I need to focus and think what happened inside circuit.

I put x10 probe (x10 key on tek display) on pentode point, 1x on low voltage signal
I think I'll check every component, cap, resistor, socket. I will be ignorant, but the p-p power should be max voltage output (undistorted) / load resistor in ohm, maybe something near 0,2w, Who has eaten the other watts?
I will find an answer!

funny picture with ear protection



Here a small noisy video, at the end you can see the sine changing

Little edit, I missed one part of formula, power is 1,5w in triode, not 0,2. power is V2/r or R*I2 or V*i