AC Bias tap?

Oddvar R · Post by **Oddvar R** » Mon May 13, 2019 10:34 am

I was wondering what the difference is between Ac Bias tap and pt TAP is. As you can see in the pics they are labelled differently.

I also wonder if the voltage regulator is grounded also in the places I have circled in red?

(Sorry if this is obvious to some)

martin manning · Post by **martin manning** » Mon May 13, 2019 10:53 am

AC Bias tap and PT Tap are the same thing... ~60 VAC with respect to the high voltage secondary's center tap. Yes, the regulator is actually grounded three times in that first snip.

Oddvar R · Post by **Oddvar R** » Mon May 13, 2019 11:21 am

So, what would it be on this pic then?

martin manning · Post by **martin manning** » Mon May 13, 2019 12:09 pm

Red/Blu is the bias tap.

Oddvar R · Post by **Oddvar R** » Mon May 13, 2019 12:52 pm

Thanks.

norburybrook · Post by **norburybrook** » Mon May 13, 2019 1:22 pm

Also, note that the green 6.5v heater secondaries have no centre tap so you will need to add resistors to create one

M

Oddvar R · Post by **Oddvar R** » Mon May 13, 2019 2:26 pm

norburybrook wrote: ↑Mon May 13, 2019 1:22 pm Also, note that the green 6.5v heater secondaries have no centre tap so you will need to add resistors to create one

M

Ok, thanks for that, didn't think of that, I must admit. How should I do it here? Two 100R's from pilot light to ground?

martin manning · Post by **martin manning** » Mon May 13, 2019 2:59 pm

Dumble layouts generally have the 100 ohm resistors from one output tube pin 2 and one pin 7 to ground.

Oddvar R · Post by **Oddvar R** » Mon May 13, 2019 3:03 pm

Ok, once again, thank you.

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AC Bias tap?

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