Finally had a chance to get back to the Henry 3KA project.
After removing the RF deck and inspecting the tube sockets and their
connections, I was puzzled when all looked good, just as the ohmmeter proved
As per the original schematic, the filaments were actually wired in series.
Upon closer inspection, I found that one of the four screws holding the
socket in place was missing, and on the bottom side, this screw actually
fastened to ground a lug which had a grid resistor and bypass cap soldered
to it. Open grid pin!
Thanks to all for the suggestions and offers of sockets.
KK2ED (ex ka2ykc)
In a message dated 10/11/99 1:56:14 PM Eastern Daylight Time,
<< Hi eric, I'm not looking at the schematic now, but you confirmed parellel
pulling one tube and teh other still lights. If there was some other path
the one tube would burn VERY brightly!
RF deck must be removed to work on this properly.
Call 800 877-7979 X240 ask for Bill, he will advise you on disassembly.
(Tell him Radiodan sent you!)
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: KA2YKC@aol.com [mailto:KA2YKC@aol.com]
> Sent: Monday, October 11, 1999 10:44 AM
> To: RFpower@radiodan.com
> Subject: Re: [Henry] Henry 3KA console - tube filament problem
> In a message dated 10/11/99 1:29:07 PM Eastern Daylight Time,
> RFpower@radiodan.com writes:
> << 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 >>
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Administrative requests: amps-REQUEST@contesting.com