[AMPS] 572 parasitic suppressors

km1h @ juno.com km1h@juno.com
Mon, 13 Oct 1997 17:25:16 EDT

On Mon, 13 Oct 1997 16:40:31 +0100 Peter Chadwick
<Peter.Chadwick@gpsemi.com> writes:
>> developed my own suppressor design for 572B's so they would work on 
>>as well as they do on 40M.  After that 10M was a snap!
>Would you mind sharing that design with us?

I have given that info out here many times. Hopefully this will be the

I use two 5W non-inductive (almost anyway) metal oxides for the R. The L
is a 2.5" x .25" x  .004" strap of Mu-Metal wound in a 1/2 turn loop on
the outside. 
 My experience of 572B's is
>that they are something akin to swine to sort out the parasitics on. 

Not really that hard to tame with the proper materials.

>KW1000  (a UK made linear in the same size box as a 30L1) used a pair
>with about 3 turns 3/4 inch diameter and 3 off 33ohm 2 watt carbon
>resistors in parallel, but I always felt it was a bit dodgy.

The old Hunter Bandit 2000A used 4 in the same case. Stable as a rock
with the old Globar resistors. 

73   Carl  KM1H

BTW, you ever get any more feedback on the folded monopole?  I'm still
totally confused. Some who commented on Topband said the ground R also
goes up 4x and others with impressive credentials privately told me that
only holds true without a radial system ....ground rod only. 
Bottom line...if the signal improves forget the experts...just enjoy it!

>Peter G3RZP
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