[ARC5] Power Supplies for the ARC-5 Rx...and others.

[David Stinson]

----- Original Message ----- 
From: "Kenneth G. Gordon" <kgordon2006 at frontier.com>
Subject: Re: [ARC5] Power Supplies for the ARC-5 Rx...and others.


> As I remember it (this occurred some years ago) I tried regulated 150 VDC
> with a view to increasing the stability of the receiver as much as 
> possible, but
> that did not work as well as raising the B+ above that point by several 
> volts,
> to around 180 VDC.

I wonder why this would be?
When I run mine on 28 volts,  they are far more
stable than at full voltage.
Is perhaps 180 volts the "sweet spot" for thermal inertia?
And if so, perhaps a much lower voltage, like 28 volts is
below the threshold where thermal inertia is a factor.

IMHO, going all the way to 180 volts defeats
the major reason to reduce B+: Preservation.
Caps that leak badly at 250 volts
are going to leak badly at 180 volts.
At 28 volts, I rarely need to change even one cap,
and when I do it's usually the audio cathode bypass.
I recapped an RAT and that was a BIG mistake.
Compared to my stock ones, it looks like crap.
Forgive me; I was young ;).
I am very willing to sacrifice performance for
the sake of perservation.  If I want to work DX,
I wouldn't do it with a BC-455.
I have plastic radios for "performance."
One doesn't enter a Ford Model "T" into a road race.
The Model "T" is for slow, leasurely pleasure drives.

73 Dave AB5S