[Amps] A question about SB-200/SB-201

[Vic Rosenthal]

Bob Green wrote:
> 
> Hi all --
> 
> Does anyone have info about the type/size wire used in Heathkit p/n 45-61, a
> 50 uH RF Choke in the HV path of the SB-201? It may be the same part used in
> the SB-200. It looks like about 28-30 gauge enamel wire.
> 
> Mine looks like it has been VERY hot, so hot that the enamel is burned off,
> but still works. 

I suggest that you temporarily short-circuit the choke and (with the amplifier
off) look for resonances with a dipmeter, particularly near 17 meters.  It's
possible that the choke has a series self-resonance near a frequency on which it
was operated and this caused the heating.  If this is the case, you may be able
to move the self-resonance by removing a few turns.

73
Vic K2VCO