[Heathkit] HW-101 questions.

[Edward B Richards]

Perhaps, since the tube is mounted on the VFO sub-chassis, the seller
thought it was the oscillator tube. Who Knows?

73, Ed Richards K6UUZ
AMI member #1534


On Tue, 26 Apr 2005 13:06:49 -0700 "Kenneth G. Gordon"
<kgordon at moscow.com> writes:
> Edward Richards wrote:
> 
> > Hi Ken;
> > 
> > That is not an unusual mod. I have done it to various receivers. 
> The idea
> > is to supply the VFO with constant filament voltage, even when the 
> radio
> > is turned OFF. This keeps the oscillator tube and compartment 
> warmed up
> > to reduce frequency drift when first turned ON. Maybe he had it in 
> an
> > unheated garage or something. He probably used an unused pin in 
> the plug
> > along with one of the two that go to the switch, to supply 120 VAC 
> from
> > the power supply. Some manufacturers, Hammarlund for one, have 
> done this
> > too.
> 
> I am beginning to think you guys are right. You are the third person 
> to 
> suggest this.
> 
> Although the VFO is an FET based unit, I suppose that by keeping the 
> 
> filaments on the buffer tube V-20 the 6AU6 in question, hot, that 
> would 
> reduce what little drift there is.
> 
> I think for my uses, I will take it out, since that way I don't have 
> to run an 
> additional wire in my PS to rig cable.
> 
> Ken W7EKB
>