Re: Brenell Purchases
Thoroughly checked out all the circuitry around the EL 84 but nothing untoward found.
Repeated tests as above and now the problem has gone away. Able to go up to 240 volts mains voltage without excess HT current or the EL 84 arcing, with typical good results as seen before.
Results at 240 volts (Playback mode) :-
Variac AC current 0.16A
DC HT voltage +332V (schematic value = 285V)
DC HT current 40mA
EL 84 Anode voltage +325V (schematic value = 270V)
EL 84 Screen grid voltage +290V (schematic value = 250V)
EL 84 Cathode voltage +9.6V (schematic value = 8.5V)
HT mains ripple 240mV p-p
Still have the very original issue of the HT voltage being too high. The value of 332 V above is 47V higher than stated value on schematic and no obvious reason found. The AC voltage across the EZ 80 full wave rectifying valve anodes is 615V which is 45V higher than stated value on schematic.
I know the values shown on the schematic are approximate but my values do seem just too high to me.
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