[Amps] Henry 2k-4 HV inductor

Elliott L kilocharlie8 at gmail.com
Tue Dec 12 15:52:00 EST 2017


Hi All,

I recently purchased a Henry 2k-4 with a high-voltage fault. The fault has
been traced to the inductor, L201, which is located directly after the
bridge rectifier.

The value, according to the schematic (I have the same PDF that most of you
have, with K9ARZ's stamp on the cover) is 8 Henry, 700mA.

Peter Dahl lists a 2k-4 choke "exact replacement" part for this amplifier,
but the value is 10 Henry. I called up the company and they verified that
the manufacturing directions do indeed specify a 10 Henry choke, and also,
that their copy of the 2k-4 schematic shows the value should be 8 Henry.

So my questions is two-fold.

1. How critical is the value of this inductor to begin with? Is there some
intentional resonance with the parallel capacitor? Wouldn't the RF be
fairly snubbed out already from C49, C48, and L11? My intuition says that
the value is not super critical, and that 10 Henry is probably better than
8, all things considered. Looking at the wiring at this DC stage, it
doesn't look like a high-tollarance tuned circuit.

2. The original part inside the amplifier has this writing on it: "14405
 FERRODYNE 13821" Does anyone have a reference for what the intended value
actually is? Other Henry amplifiers in this line (2k-x, 2k-classic, etc)
have 8 Henry, so I am inclined to believe that 8 Henry is correct, but a
reference back to the original part would be pretty good evidence.

And more ancillary question, the original is rated for 700 mA. Would that
likely be intermittent or continuous?

Thanks very much (and great mailing list!),

--Elliott
W6EL


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