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Re: [Amps] 2K Classic X filament issue

Subject: Re: [Amps] 2K Classic X filament issue
From: Victor Rosenthal 4X6GP <>
Date: Tue, 3 Aug 2021 21:56:25 +0300
List-post: <>
I would have said the same, except that the filaments are in series. That implies that the same current must be flowing through both of them. If one set of contacts is dirty, then the current through both tubes would be reduced.

Victor, 4X6GP
Rehovot, Israel
CWops #5
Formerly K2VCO

On 03/08/2021 20:58, David Gow wrote:
I had the same on my 2KD-3.  Turned  out the tube socket pins on one
socket were a little dirty/corroded.  Cleaned and tightened them and
all is well now. Dave W7VM

On Tue, Aug 3, 2021 at 10:44 AM Donald Fox via Amps
<> wrote:

Gents: As you may recall, I have a soft spot for the Henry Classic
consoles. I recently acquired a 2K Classic X console from the
original owner, and want to being it back to life. It's interesting
to note that This 2KX was originally built as a domestic 2KX, with
the smaller plate xformer. The owner eventually purchased the
larger export 1171 plate xformer, and installed it. The amp was
purchased from AES in Wickliffe, Ohio,  back in the early 80's, and
used frequently until the owner left town in 1986. From then on, it
sat unused for 35 years.

After a thorough cleaning, I am seeing a brightness difference in
the 3-500z tubes. I tried swapping the tubes from front to back,
and the front tube consistently has the weaker filament. I have
also tried a second, known good set of tubes, with the same
results. A visual inspection of the underside of the RF deck
revealed no obvious problems. Filament voltage is around 11
unloaded, as the filaments are in series.

I have not enabled the HV section as of yet. The bearings in the
blower were semi frozen, such that a new motor was required. That
part is done.

Thoughts and suggestions please.


Don    N8ECH _______________________________________________ Amps
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