Voltage check, all good, Terminal 2 & 4.. meh?

trickyricky123 · 1371

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Offline trickyricky123

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on: September 01, 2022, 05:37:00 AM
Heya,

Doing a final voltage check - looks OK - but depending on the 9 pin tube I'm using the T2 & T4 values can go out of 10% range? (190V) Is this something to worry about?

With the stock tube I am coming up with:

T1: 84V
T2: 183V
T3: 0V
T4: 183V
T5: 82V

T6: 0V
T7: 99V
T8: 0V
T9: 99V
T10: 0V

Thank you!



Offline Paul Birkeland

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Reply #1 on: September 01, 2022, 08:02:30 AM
What is your incoming AC line voltage?  I would guess you have something close to 125V and you are wired for 120V, but making an incorrect selection here can also lead to higher voltages.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline trickyricky123

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Reply #2 on: September 01, 2022, 08:55:47 AM
Input AC 229V, sometimes up to 234V. I went and soldered according to "IF your voltage is GREATER than 225V AC and LESS than 235V AC:"



Offline trickyricky123

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Reply #3 on: September 02, 2022, 06:50:32 AM
Would it be worth a shot connecting terminal 15 & 16 instead of 14 & 16 on the power transformer to lower these values?



Offline Paul Birkeland

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Reply #4 on: September 02, 2022, 11:51:08 AM
You could certainly move that wire and give it a shot.  Things being a little high at 235V isn't all that surprising, but if your line voltage wanders down to 229V, I would leave it as-is.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline trickyricky123

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Reply #5 on: September 02, 2022, 08:57:21 PM
Thank you!

Any risks involved either with the current situation of 190V being reached or when dropping too low after a change?



Offline Paul Birkeland

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Reply #6 on: September 03, 2022, 12:40:27 PM
The high voltage isn't really a huge issue, and you have to be pretty far off to start stressing the 250V power supply caps.  What can be concerning is if the 6.3V heater winding is running way over or under spec, as that can be detrimental to tube life.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man