[Hammarlund] Fwd: Re: Super Pro bias supply

[Richard Knoppow]

----- Original Message ----- 
From: <ve3ajm at gmail.com>
To: "hammarlund" <hammarlund at mailman.qth.net>
Sent: Wednesday, July 25, 2012 6:45 AM
Subject: [Hammarlund] Fwd: Re: Super Pro bias supply


>
>
> Sent from my HTC
>
> ----- Forwarded message -----
> From: "ve3ajm at gmail.com" <ve3ajm at gmail.com>
> To: <wrcromwell at gmail.com>
> Subject: Re: [Hammarlund] Super Pro bias supply
> Date: Wed, Jul 25, 2012 9:43 am
>
>
> A fuse would help protect the driver transformer. Shunt 
> feeding the transformer would remove the DC from it 
> complely too.
>
> Al

      I suspect the choice of driver was made to insure a 
low impedance path for the grid current. Hammarlund may have 
chosen AB2 to increase the power available from the 
amplifier but it complicates the grid drive requirements 
since the driver must supply a small amount of power to the 
final grids.  A fuse in the B+ would probably protect the 
transformer.  Of course, one could completely replace the 
audio amplifier stage with something more modern:-)


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com