0A2 0B3 replacement

[ndham]

Hello,

I have  a high voltage high amperage tube power supply.  Huge transformers and tubes.

The 0B3 and 0A2 tubes were dismally out of spec.  When I replaced them with NOS they were no better probably due to gas leakage.

I wanted to replace the with a zener and was told by retired tv repairman from tube days that they wouldn't work because of impedance differences.

Any suggestions?  The unit works well interestingly except for voltage drift.

Thank you.

[Gary Lecomte]

I Do Not Know What "NOS" is?

What Voltage do you need to Regulate too?
From My Data Book, the 0A2 regulates to 150 VDC within a Range of 5 to 40 mA., and a 6.5 volt Variation.
The 0B3 Regulates to 90 Volts, within a Range of 5 to 40 mA., and a 8 volt Variation.

Yes this can be Done with Zener's and probably more stable.
I did this one time on an old tube unit.

But you need to know the Output Currents on these.
Is the Current Draw Constantly the Same, or does it Vary a lot?

I Have 7.5 Volt, 11 Volt, 12 Volt, 36 Volt, 39 Volt, 60 Volt zeners, All rated at 5 Watt.
These can be in Series to get the Voltage you need.
And you will also need a Suitable Resistor, Based on Currents.

[ndham]

Jan 8, 2016 11:13:29 GMT -8 Gary Lecomte said:

I Do Not Know What "NOS" is?

What Voltage do you need to Regulate too?
From My Data Book, the 0A2 regulates to 150 VDC within a Range of 5 to 40 mA., and a 6.5 volt Variation.
The 0B3 Regulates to 90 Volts, within a Range of 5 to 40 mA., and a 8 volt Variation.

Yes this can be Done with Zener's and probably more stable.
I did this one time on an old tube unit.

But you need to know the Output Currents on these.
Is the Current Draw Constantly the Same, or does it Vary a lot?

I Have 7.5 Volt, 11 Volt, 12 Volt, 36 Volt, 39 Volt, 60 Volt zeners, All rated at 5 Watt.
These can be in Series to get the Voltage you need.
And you will also need a Suitable Resistor, Based on Currents.

[ndham]

It has 2 OA2's in series I have noo isea of the amperage. Would a reading off of the power transformer suffice. I am in the process of replacing the caps on the unit.
noS is new old stock. These tubes have all been contaminated by room air over the years. I am going to solid state this unit as much as I can. It has 6l6's for the regultor stages which I will preserve.

Against all advice I replaced the ballast tube on my r390a with an amplified zener and wukll replace the oa3 on it witha zener too also.

I thank you kindly. I was reading a technical article on these tubes saying not to use a zener because its impedance is too low. I haven't read this anywhere else so its the ppinion of the that person most likely.

Thank you kindly ffor your helpful response

[Gary Lecomte]

I am presently on a Holiday in Punta Arenas, in Chile.

It is Possible to use Zeners, But I need More INFO, WHEN I Get Back Home!