I have checked signals with the scope (measured with 1:10 probe with DC coupling, 500 mv/div so 5V/div considering probe).
Ground level:
?
DC level on drains of finals without RF:
?
Voltage with RF on the drain of the first final transistor:
?
Voltage with RF on the drain of the second final transistor:
?
At the same time, the voltage on the secondary coil of the output transformer looks like below (100mV/div - 1V/div considering probe)
?
Is it possible that the transformer got broken due to overheat, or that something in the LPF filter shortens the signal?
?
73,
Wojtek
