[1000mp] MPV Driving SB220

[Jan Erik Holm]

Yes yes, I should have know, I´ve also worked on
them a lot, thats why I was so sure, I can not
explain, I was just "dead wrong".

73 SM2EKM
---------------------------
Mike Schatzberg wrote:
> Hello Jim:
> 
> Heathkit part number 69-55, is a TPDT relay, with a 110 VDC coil.  It is
> indeed driven by switched DC voltage from the simple half wave power supply
> circuit off of one of the transformer windings.
> 
> Perhaps Heathkit produced more than one version of the switching, which
> handles both antenna transfer duties and bias switching.
> 
> I have changed many of these amps to QSK using vacuum and reed relays, and
> usually have several pulls in the junk box here.  They are all DC relays.
> 
> 73 and Happy DXing,
> 
> Mike
> W2AJI