Re: T912 storage oscilloscope - No 2.7 KV high Voltage


Attilio
 

Hi Roger,
the CR468 heats only with the C468 condenser connected, if I disconnect it the CR468 remains cold.
I wanted to add that I measured the voltages at pin 2 and pin 7 of the T460 transformer with respect to ground and I find very high voltages (on pin 2 there are 840 Vpp at 53 kHz and on pin 7 there are 484 Vpp at 53 kHz).
From pin 2 through the CR468 diode the - 120 Vdc are generated and from pin 7 through the CR467 diode the - 220 Vdc are generated, 840 Vpp to generate the -120 Vdc seem too many! I suspect an insulation problem in the T460 transformer (?).

--Cheers
Attilio

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