[Hammarlund] Super Pro bias supply

[Brian Harris]

If one installed a relay in the power supply which is energized by the bias supply and whose contacts, when closed, allow B+ to flow, would solve the scorched driver transformer.  Seems simple enough to me.

 
Brian Harris
cell 214-763-5977
email cosmophone at yahoo.com


________________________________
 From: Bill Cromwell <wrcromwell at gmail.com>
To: Al Santangelo <ve3ajm at gmail.com> 
Cc: hammarlund <hammarlund at mailman.qth.net> 
Sent: Wednesday, July 25, 2012 6:37 AM
Subject: Re: [Hammarlund] Super Pro bias supply
 
On Wed, 2012-07-25 at 07:16 -0400, Al Santangelo wrote:
> OK on the further information.
> So then, what is the connection between the failure of the
> -50v bias supply and the failure of the audio driver transformer that
> I've read about?
> This bias supply is not connected at all to the audio driver
> transformer ie.T7 in the SP-400X receiver. Thanks.
> 
> Al Santangelo
> ______________________________________________________________

Hi Al,

I went to BAMA and snagged a copy of the manual. If the bias supply
fails the audio driver will turn full on (zero volts at the control
grid) and it gets it's plate voltage through that transformer. The
transformer will be ruinated. You can't stuff tens pounds of baloney in
a one pound sack.

73,

Bill  KU8H

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