Amperite 3A20--Help needed.

Harold Wright · **Posted:** Oct Thu 17, 2019 11:12 pm

I found a NOS Amperite 3A20 in some tubes from an estate. I tried to research it on the web but not much help.
Any info. would be appreciated.

Harold

processhead · **Posted:** Oct Thu 17, 2019 11:36 pm

That is a current regulator ballast tube.
Not sure what its ratings are though, yet.

http://www.labguysworld.com/AMPERITE_BALLAST_TUBES.pdf

Norm Leal · **Posted:** Oct Fri 18, 2019 1:31 am

Harold

Regulates at 300 ma with voltage between 20 and 41.

processhead · **Posted:** Oct Fri 18, 2019 2:04 am

Norm Leal wrote:

Harold

Regulates at 300 ma with voltage between 20 and 41.

Norm, where did where did you locate the rating?

Norm Leal · **Posted:** Oct Fri 18, 2019 2:07 am

The Ballast Tube Handbook.

It's also in Radio Electronics Master. This is a large book which came out every year and given by Distributers.

Harold Wright · **Posted:** Oct Fri 18, 2019 2:32 am

Norm

Thanks. I do not have those books--very interesting.

Harold

Number 6 · **Posted:** Oct Sun 27, 2019 4:46 am

For someone who has a particular Jackson VTVM, a 3A20 tube is used in that unit.
viewtopic.php?f=8&t=334464&hilit=3a20
Probably nothing else requires that tube.

Jeremy S · **Posted:** Oct Tue 29, 2019 8:44 pm

Here is a PDF version of the ballast tube handbook.

https://www.americanradiohistory.com/Ar ... ok-opt.pdf

Amperite 3A20--Help needed.

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