tubes age 93
DC-heated, while an AC-heated filament would be more likely to lose emission
more evenly. Barry Ornitz may have a better idea of what happens here, and I'd
be happy to hear what he has to say on the subject.
Ah! A short Google search on `"power tube" filament supply yields lots of
relevant hits. One of the more interesting ones is about the Burle S94000E
Power Tube, Its filament supply must provide 3.5 VDC at 4200 Amperes. Yes,
that's Four Thousand Two Hundred Amperes to heat the filament. This is a
_big_ tube: it weighs 325 pounds out of its crate, and 870 pounds crated. The
tube's data sheet says:
A DC filament supply is required. Filament excitation with an AC
supply may generate mechanical resonances in the filament
structure. A three-phase, full-wave rectifier supply is recommended.
The operating region on the voltage-current chart tops out at about 90 A with a
drop across the tube of 20 KV. At 30 KV, the current is reduced to "only" 65 A or
so. This is typical of large power tubes, judging by what else I found on Google.
Still, I hope Barry O. will give us the benefit of his education and experience.
--------------------------------------------------------------------------------------------------
Date: Tue, 15 Jan 2002 09:53:50 -0800
Subject: [R-390] 6DC6 Replacement
Warning Solid state devices discussed in this post. POST NOT SUITABLE FOR
ALL READERS. What ideas are there for plugging a transistor into the 6DC6
RF amp socket of the R390/A. I am looking for: equal or better sensitivity. equal
or better gain. lower device noise to produce an over all receiver improvement
in the signal to noise whatever. Good 7 pin metal relay cans exist to house
(conceal) [shield] the device. Considering the nature or the RF deck underside,
I am going for a plug and pray modification into the tube socket on the top side.
What's been kicked around and deemed undoable because it violates nature?
------------------------------------------------------------------------------------------------------------
Subject: Re: [R-390] 6DC6 Replacement
Date: Wed, 16 Jan 2002 09:25:17 -0800
Fellows, Alright! I must confess that I have had similar evil thoughts.
WARNING---SAND STATE THOUGHTS TO FOLLOW!!!!
I have found Bill Noonan W6WJN in San Francisco. He really did the tubsters.
Bryce Ringwood, wrote me with some attachments we can not get through the
reflector mail. "I made a solid-state set in the '70s that worked something like
this. It was(is) sensitive and low-noise, but really REALLY bad with nearby
strong signals." nearby strong signals is not a DX objective so we can skip over
those things. We can hang a bridge rectifier and load across the feed line. Any
(14 pages)
(10 pages)
Manymanuals.com
Manymanuals.de
Manymanuals.fr
Manymanuals.it
Manymanuals.pl
Manymanuals.cz
Manymanuals.es
Manymanuals-pt.com
Commentaires sur ces manuels