[Amps] Henry 2KD-5 120 Hz Hum

[R L Measures]

The Henry 2KD-5 does not use a resonant-choke filter, it has a C filter.

On Aug 6, 2006, at 5:09 PM, Leigh S. Jones, KR6X wrote:

> Henry amplifiers use resonated chokes to achieve their normal high
> attenuation of HV power supply hum rejection.   If the resonating  
> capacitor
> has broken down, or if there has been a short across the turns of the
> inductor, the hum level would increase with a few attendant  
> symptoms.  The
> symptoms might include an increase in the unloaded plate voltage  
> and reduced
> stability of the HV.
>
> ----- Original Message -----
> From: "hamguy2" <hamguy2 at fuse.net>
> To: <amps at contesting.com>
> Sent: Sunday, August 06, 2006 11:56 AM
> Subject: [Amps] Henry 2KD-5 120 Hz Hum
>
>
>> I have a Henry 2KD-5 that I am using on AM running 300 watts.
>> There is a low level but noticeable 120 Hz hum on the unmodulated
>> carrier in CW mode.  The hum is super imposed on the AM signal
>> amplitude.  Local stations can hear the hum.  I have tried two
>> exciters and they are not the source.  I have recapped the filter
>> capacitors to 250 mF without change in symptoms.
>>
>> Is there something else to check or do I just live with the hum?
>>
>> ----------------------
>> Ron Schuster N9RC
>> ----------------------
>>
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>
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R L MEASURES, AG6K. 805-386-3734
r at somis.org