[AMPS] Amps in Sept QST

[km1h @ juno.com]

On Wed, 27 Aug 1997 08:57:31 +0008 "George T. Daughters"
<gdaught6@pobox2.stanford.edu> writes:
>
>hi tom,
>
>> Are you sure? Why does a HF PA have a 4:1 transformer in the tank?
>> That seems non-conventional.
>
>pretty non-conventional, but the plate tank (pi circuit) matches from 
>the anode level down to 200 ohms, then the transformer gets you down 
>to 50, nominal.  at the very leaset, it means you don't need an rfc to 
>ground 
>for safety.  i haven't done the calculations, but it might end up 
>looking like a 
>pi-L output network.  
>
>what i'd really like to know is what sort of troubles with the 
>transformer can be causing IMD ratings to change?

Once overheated beyond a certain point the cores become permanently
non-linear. This is particularly true with ferrite. Powdered iron can
develop fractures which result in similar problems. I do not know what
materials QRO and Command use for their 4:1.

73....Carl  KM1H


>
>73,
>George T. Daughters, K6GT
>
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