[HBR] HBR Tuning Cap, Coil Forms

[frank]

Good air variables are getting harder to find. 

If you are lucky enough to have a three section 365 variable, instead of
removing plates you might do better to install some capacitance in
series with the sections.  If the series caps are variable, they will
allow you to trim the main cap to get proper tracking.

In any case, I hate to see someone butcher a perfectly good cap for a
custom application.  If you don't want to fool with the series caps,
sell the triple section 365 and use the proceeds to buy a variable
closer to your needs.

Frank Kamp


Mike Feher wrote:
> 
> Removing plates from a triple 365 may not be as bad as made out to be. They
> need not be adjacent plates but could be spaced to give the required
> capacity, decreasing the effect of mechanical rigidity on capacitance. The
> one problem, if it can be seen as such,  is the physical size of the
> original 3 gang 365 would still be pretty big. I believe I have read and
> seen enough departure on this reflector from the original design that a few
> more may not be that harmful to allow one say "I have an HBR". I feel an
> easier solution may be to use a dual section and then have an antenna
> trimmer capacitor which is seperate. Most tube receivers ganged and
> therefore had to track all tuned sections, but, recently with synthesized
> oscillators and all, most receivers do have a seperate front end control.
> Doing this would require only a dual section for the main variable and would
> be easier on tracking. It is hard to believe that 40 years has gone by since
> I built my first HBR receivers. Happy Holidays & 73 - Mike
> 
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell NJ, 07731
> (732) 901-9193
> 
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