Hi Eric,
The filaments are wired in parallel. You will have to take the RF deck apart
and find the bad connection on the one tube socket.
Possibly melted solder from the pin getting too hot due to large filament
current drawn through one small spot of conductivity.
When this is repaired check socket pin tension and clean/burnish pins.
This must be done from under the chassis.
73, Dan Magro W7RF, (President WARC 1999, member SCDXC, SCCC)
Manufacturers Rep & Distributor for HENRY RF Power Amplifiers.
RF Applications Power Measuring equipment, See the VFD & WinWatt!
www.radiodan.com <http://www.radiodan.com> RFpower@radiodan.com
<mailto:RFpower@radiodan.com> A trip to our web site is worth the click!
> -----Original Message-----
> From: owner-henry@contesting.com [mailto:owner-henry@contesting.com]On
> Behalf Of KA2YKC@aol.com
> Sent: Monday, October 11, 1999 9:35 AM
> To: amps@contesting.com
> Cc: henry@contesting.com
> Subject: [Henry] Henry 3KA console - tube filament problem
>
>
> Hello all;
>
> I am attempting to repair a Henry 3kA console with a pair of
> 3-500Z's for a
> friend. Only the left side tube's filament is lighting. The
> right side is
> stone-cold.
>
> Doing an A/B swap still results in the right side not lighting.
> Pulling the
> right (unlit) tube, the left tube still lights.
>
> After pulling the tubes, I inspected the tube sockets. All looks
> OK. I took
> some measurements with an ohmmeter, and pin5 of left tube has a good
> connection to pin1 of right tube. Pin1 of the left tube and Pin5
> of the right
> tube have good continuity to the filament transformer. I measured
> less than
> 10 ohms on the secondary of the filament transformer when totally
> disconnected via the jones connection. My next step is to wire
> the meter to
> each socket and take some voltage measurements with power
> applied. Stopped
> short there last night as I was getting too tired and didn't feel
> like making
> a deadly mistake due to fatigue.
>
> Before I dig deeper and pull the RF deck off the console for further
> inspection (the tube socket base assy is a bear to get to!), does
> anyone have
> any suggestions ?
>
> Is it possible for the one tube to light without the other tube in place
> (like the old christmas lights where one bulb out causes the rest
> to go out)
> ? It appears they are wired in series, but is it possible the
> transformer has
> an opening on one side of the secondary, and I am getting a
> return to ground
> via another path? (I checked the caps to ground from the fil.
> pins, and all
> are ok) Gave up last night, maybe I am missing something too obvious ??
>
>
> TIA for any suggestions.
>
> 73 Eric
> KK2ED (ex ka2ykc)
>
>
>
>
> --
> Sponsored by Radiodan W7RF and Henry Radio.
> FAQ on WWW: http://www.contesting.com/henry-faq.html
> Submissions: henry@contesting.com
> Administrative requests: henry-REQUEST@contesting.com
> Problems: owner-henry@contesting.com
> Search: http://www.contesting.com/km9p/search.htm
>
>
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|