[AMRadio] Filament Voltage

[Dan Hall]

Well:
As usual, I've gone off half cocked. It turns out that the total voltage
drop, as measured from the PA tube filaments, using an external meter, is
only .36VAC. According to the book, +/- .5 is allowed. I have now set the
voltage at standby to 10.35VAC and let it droop to 9.99VAC.
Should be fine.

Thanks for the patience
Dan
----- Original Message -----
From: "Gary Schafer" <garyschafer at attbi.com>
To: <amradio at mailman.qth.net>
Sent: Monday, March 25, 2002 6:47 AM
Subject: Re: [AMRadio] Filament Voltage


>
>
> wwd at netheaven.com wrote:
>
> > >I have very poor filament voltage regulation on the Gates BC1-J.
> > >Dan
> > >KJ7FX
> >
> > Time for a new 30A 240v cable run to the shack. I trust the Gates does
not
> > have only 120v primary like the T-368. For my T-368 I've collected a few
> > ~20 lb 440/220<=>220/120 transformers so the T-3 will source thru both
> > legs only, and not thru the neutral. If this doesn't actually improve
> > voltage regulation it will at least balance the load.
> >
> > Otherwise, this would seem to be a perfect candidate for a modern
> > solid-state solution. But I gag on using SCR's or the like, given their
> > propensity to scatter broadband hash in all directions. Anyone have the
> > elegant fix?
> >
> > Bill        N2KQA
> >
>
> A relay and two pots. One to adjust transmit voltage and the other for
standby voltage.
>
> I don't know about the 833 but in looking at the tube manual on the 813
they recommend that if
> the standby period is less than 15 minutes, the filament voltage be
reduced to 80% of normal.
> If the standby period is greater than 15 minutes, turn it off.
>
> 73
> Gary  K4FMX
>
>
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