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Old 31st Oct 2019, 3:10 pm   #32
Join Date: Nov 2016
Location: Budapest, Hungary
Posts: 323
Default Re: Vintage Radio and Phonograph cutter schematic

Thanks Lawrence,

Disconnected the Y2 capacitor and connected the chassis to the mains earth. No AC voltages can be measure in the chassy (does this mean that the brand new Y2 cap from Farnell was failing?)

Before i go further, I am feeding this turntable with 110VAC not 117VAC due to my step down converter, I assume some voltages will be a bit lower.

V1 has heater voltage of 6VAC.

Junction C10 and R19 is 172 V.

I found some discrepancies what I see in the unit and what I see on the schematic and what is in the component list...I hope I see this correctly...

the R39 on the schematic is 10kOhm but the R39 in the components list is 100Kohm

Also, the V3 and V4, the pin 3 i think it is the grid and the grid resistors both were 500kohm in the unit, but on the schematic V3 has 500kOhm and V4 has 100 Kohm. ....I did try to follow the schematic and when I did that the V4 anode pin 8 voltage went up to 137Volts. I put both resistors back how it was, both 500kOhms...

what would you advise Lawrence ? arent those anode and g2 voltages to high? nearly double compared to that chart...

with regards the mains cable, do i need to simply change the two prong to 3 prong? Many thanks for your help, as always.
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