>-- "Phil Clements" <philc@texascellnet.com> wrote:
>

<snip>

>
>Harris has been doing this for years in their amps. The RF->110, 
>(pair of 4CX1500B's) has a plate choke that is a very small ferrite 
>loaded unit that is clean from 1.8-30 mhz. This was the ideal fix 
>for adding WARC bands and 160 meters, but the amateur amp 
>manufacturers did not pick up on this.
>

<snip>

>(((73)))
>Phil Clements, K5PC


Hi Phil,
  If I recall correctly, that choke is listed on the schematic at 
115uH.

  Employing the ferrite core should place the first (parallel) 
resonance suitably above 30 MHz.

  This appears to be a valid approach because of the low plate 
impedance (circa 1000 ohms).  Though there will still be plenty of 
reactive current through that choke on the lowest bands.

  Still a compromise, albeit a less objectionable one than 
most "amateur" amps.

  I'm feeling just a bit of deja vu all over again. :-)
  To see why, start at this old link:

   http://lists.contesting.com/_amps/2000-03/msg00603.html

73 & Good evening,
  Marv WC6W

http://wc6w.50webs.com/








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