[AMPS] Chokes

[measures]

>
>>The highest L  choke that has no resonances below 30MHz is c. 65uH.
>
>A data point for the choke discussion:
>
>   An article by Bill Deane in "73 Magazine", September 1969, p. 147
>describes a 90 uH choke with a (first) resonance at 43 Mhz.
>
  With an air core, a 90uH choke resonates in the neighborhood of 20MHz.  
Ferrite cores have a well-deserved reputation for saturating in actual 
use.  .  

>   The cogent details, to save everyone a trip to the library, are sixty
>turns of #20 wire, space wound 4" long on a 3/4" diameter form with a 3"
>x .33" ferrite rod mounted in the center of the form.
>
The Collins antenna tuner used in the B-52 had a roller coil with a 
ferrite core at one end of the coil.  .   The core only came into play at 
low frequencies.  I have never heard of a ferrite core being successfully 
used in a hv rfc.  

later,  Marv

-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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