[ARC5] BC453 on 24V - screen voltage

[D C _Mac_ Macdonald]

The 6SN7GT dual triode (regen detect + audio amp) of the Walter Ashe Novice station used 150 VDC regulated.  I found that little receiver to be MUCH better than the S-38 I borrowed when the 6SN7GT went dead and I didn't have the money to buy a replacement tube back in 1954.

73 de Mac, K2GKK/5​
Since 30 Nov 1953​
Oklahoma City, OK​
USAF, Retired ('61-'81)​
FAA, Retired ('94-'10)​

________________________________
From: arc5-bounces at mailman.qth.net <arc5-bounces at mailman.qth.net> on behalf of Kenneth G. Gordon <kgordon2006 at frontier.com>
Sent: Tuesday, December 10, 2019 18:45
To: ARC-5 Maillist <arc5 at mailman.qth.net>; Hubert Miller <Kargo_cult at msn.com>
Subject: Re: [ARC5] BC453 on 24V - screen voltage

On 10 Dec 2019 at 23:22, Hubert Miller wrote:

> My point is, I suspect you cannot linearly scale down the HFO plate
> voltage as the B+ supply line decreases.

Probably not...but there is, and has to be, some sort of relationship. The B+ voltage on the
HFO cannot remain at 30 VDC if the main source from which that is derived is 24 VDC, can
it? "That is not logical, Walter."

> My experience is that it is
> quite difficult, for example, to build a regenerative receiver with a
> plate voltage below something like 6 volts.

Yes.

> Very interesting idea, that the HFO plate was maintained at low voltage to minimize frequency drift. That
> the % voltage change with B+ varying remains the same, while the absolute HFO delta Ep is less.

Again, yes.

Ken W7EKB

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