Lou, I've seen that, too.
I've also seen the resonating cap short out (choke is still fine) and B+ soar
to 6kV and they just keep operating.
Something will eventually fail, but those big oil-filled caps can often handle
6kV for quite a while, and so can the tubes in many cases.
-----Original Message-----
From: Amps <amps-bounces@contesting.com> On Behalf Of gudguyham--- via Amps
Sent: Tuesday, September 5, 2023 4:24 PM
To: Rob Atkinson <ranchorobbo@gmail.com>; amps@contesting.com
Subject: Re: [Amps] Subject: Henry hum on transmitted signal
Rob, it seems as though is not “if” but “ when” the choke craps out in those
Henry amps. I’ve seen where many chokes shorted to the core and guys mounted
the choke on insulated material instead of getting a new one. Lou
Sent from the all new AOL app for iOS
On Tuesday, September 5, 2023, 7:14 AM, Rob Atkinson <ranchorobbo@gmail.com>
wrote:
I think the resonant choke design is clever by a half. It's just too finicky
and failure prone for my liking. Also, I've seen a choke Henry used in one of
their amps, I forget which one but it was supposedly rated for 700 ma. I have
a 700 ma filter choke out of a 1 KW broadcast rig intended to run continuously
and it's at least twice as big and heavy as the dinky thing Henry used. I've
seen I don't know how many RF power amplifiers designed for volatile loads like
SSB and CW and they did fine with nothing but around 40 mfd capacitance for a
filter. I would only use a choke input for power supplies serving transmission
modes that put the supply under continuous load, such as AM and RTTY. I would
rebuild that power supply for whatever xmission mode is intended and ditch that
resonant choke scheme.
73
Rob
K5UJ
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