[R-390] Role of the 3TF7 in PTO frequency changes

[Heinz Breuer DH2FA]

I don't see it that way. Kurt confirms Dallas' observation, that a 
change of the mains voltage will cause a variation in pto frequency due 
to variation of the pto tube's filament supply which is regulated by the 
3TF7.
A 12Hz jump for a 9% mains voltage change is probably nothing serious to 
worry about and the 3TF7 might have been the best regulator available in 
the mid 50s to achieve this. Nevertheless a solid state regulator can 
even avoid this 12HZ jump.

I am not into digital modes, a 12 Hz jump doesn't bother me.

vy 73 de Heinz DH2FA, KM5VT


Shoppa, Tim schrieb:
>> I can document that the current regulator 3TF7 is the main cause for
>> the observed PTO frequency changes.
> 
> I think something gets lost in the translation from German to English.
> This is like saying that fire trucks cause fires.
> 
> Tim.
> 
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