[Amps] Henry 2KD-5 120 Hz Hum

[W7RY]

The filaments are in series. It would take 10V @ 15 amps.


I'm not sure using DC would be a good test. You need the center tap for
the cathode return.


73
Jim W7RY


-----Original Message-----
From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]
On Behalf Of GGLL
Sent: Monday, August 07, 2006 7:32 PM
To: Amplificadores Lineales
Subject: Re: [Amps] Henry 2KD-5 120 Hz Hum

	A crude test could be to feed both filaments with DC?, at least
temporarily 
for testing purposes. A cheap power supply (although it is required to
rewire 
the filaments in parallel), would be a personal computer one, Its 5V
output in 
most cases are rated to 30A.

Best regards
Guillermo - LU8EYW.

R L Measures escribió:
> On Aug 6, 2006, at 2:09 PM, Tom W8JI wrote:
> 
> 
>>>It could be 60 Hz.  It sounds like 120 though.   A local
>>>ham with
>>>band scope said 60 Hz and not a perfect sine wave.  He
>>>said it was
>>>riding on the signal about 20 dB down.  This is an amp I
>>>acquired
>>>recently and the hum problem has existed since I started
>>>using it.
>>
>>Sounds like a filament balance problem to me.
> 
> 
> Agreed.  The 2KD-5 has seriesed filaments.
> 
>>73 Tom
>>
>>
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> 
> 
> R L MEASURES, AG6K. 805-386-3734
> r at somis.org
> 
> 
> 
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