[Heathkit] SB-220

[wb8jkr at juno.com]

26 ohms sounds high, I would think those chokes
should only have maybe 4-5 ohms max. Make
sure you have continuity between the supply B+
output and the actual plate caps of the 3-500's
you might have an open plate choke, although
I would seriously doubt it.
Also, make sure the grid current measuring
circuitry is ok, any open in the DC path of
the grid circuit would bias the amp off.

Mark  WB8JKR


On Thu, 25 Nov 2004 12:08:29 -0500 "Don Flenner" <w4ych at earthlink.net>
writes:
> Mark,
> 
> The voltages are switching  when the relay is energized measured at 
> pin 8 of 
> the relay. Also measured from grid to ground and I get about 26 
> ohms. The 
> original 1mh chokes are still installed on the 3-500z's.
> 
> 73,
> Don, W4YCH
> http://www.home.earthlink.net/~w4ych
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> ----- Original Message ----- 
> From: <wb8jkr at juno.com>
> To: <w4ych at earthlink.net>
> Cc: <heathkit at mailman.qth.net>
> Sent: Thursday, November 25, 2004 11:20 AM
> Subject: Re: [Heathkit] SB-220
> 
> 
> >  Probably a dirty relay contact. The bias should
> > switch between about -100 volts and -5 volts
> > between rec & xmit.
> >
> > Mark  WB8JKR
> >
> 
> 
> 
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