Doug wrote:
Hi Doug:
I've got a few friends who use the 4-400's in place of the
more expensive 3-500Z's. In fact one who just prefers them.
They are a rugged tube, and will work well in GG service.
If you can find it, look for W6SAI's info on the 4- series
tubes and how to set them up in GG service. I've got one
copy here and wont let go of it, but could run some copies
of it if you needed it. Title is "Care and Feeding of Power
Tetrodes". Lots of good info in it, how to run 'em, how to
destroy 'em. I'm sure it's out there in the world somewhere.

That paper is available on the Eimac website, in something like 8
sections, and is Well Worth The Download.

Google for it and it should show up.

The 4- series of tubes was built for broadcast and military
use, designed to run bright red and will take a lot of abuse.
I use a 4-1000A here on CW (when I need it) and have had no
trouble. 3rd order is down 34 DB, output power is 1450
watts at 4 kv. It was a beast to tame for parasitics, but
some of AG6K's nichrome chokes and it came right into specs.

Great bottles!

Yes, indeed. They were viewed -- rightly -- as very innovative and
brilliantly designed when they were introduced, and I've seen nothing
to contradict that evaluation.

--
Mike Andrews

Tired old sysadmin

Mike Andrews wrote:
Doug wrote:
Hi Doug:
I've got a few friends who use the 4-400's in place of the
more expensive 3-500Z's. In fact one who just prefers them.
They are a rugged tube, and will work well in GG service.
If you can find it, look for W6SAI's info on the 4- series
tubes and how to set them up in GG service. I've got one
copy here and wont let go of it, but could run some copies
of it if you needed it. Title is "Care and Feeding of Power
Tetrodes". Lots of good info in it, how to run 'em, how to
destroy 'em. I'm sure it's out there in the world somewhere.

That paper is available on the Eimac website, in something like 8
sections, and is Well Worth The Download.

Google for it and it should show up.

Oops! The Eimac paper is at http://www.cpii.com/eimac/index.html,
in 6 sections. It's a classic.

Which doesn't say that W6SAI's work isn't. I'll look for it.

--
Mike Andrews

Tired old sysadmin