HP-23 Upgrade

[Russ Hines]

First, thanks to Mike for making this product available.  I'm not a customer
yet but I have (2) HP-23 supplies that could use this.  Maybe Santa will
help out on this one. ;-)

As for regulating the HV, I think it's a case of diminishing returns.  In
other words, the expense of regulating 800 VDC exceeds the benefits
obtained.

As far as I know, the 6146's are the only tubes that use the HV in the rigs
with which this supply was used.  Regulating the 300 VDC B+ is good because
almost every other tube in these rigs use this for its plate supply, plus
other voltages (screens and 150 VDC) are derived from it.  Regulating the B+
makes for a nice, stable radio, worth the effort.  At least Heath didn't
attempt to run the LMO from the B+ like Drake did.

I think it's better in the end to have well-filtered HV for clean final amp
performance.  For example, broadcast transmitters using vacuum tubes
generally use simple, adequately-filtered (sometimes just barely) but
non-regulated linear HV supplies for the final amps.  The key is a supply
that is capable of delivering more current than the tubes require.  Seems to
work just fine, at power levels and voltages far exceeding what we see even
in our legal-limit amplifiers.

My two-cents in.

73,
Russ Hines
WB8ZCC



----- Original Message -----
From: "Stephen Tetorka" <StephenTetorka at CS.COM>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Wednesday, December 10, 2003 11:38 PM
Subject: HP-23 Upgrade


> Hello to all:
>
> I am thinking of 'upgrading' my HP-23A or my HP-23B via the kit being
> supplied by WB8VGE ( see www.theheathkitshop.com ) and described in QST of
October
> 2003.
> The nice thing about this version is the regulation of the LOW voltage -
300
> Vdc supply.
>
> Comments are welcome.
>
> Any suggestions as to how I could regulate the HIGH voltage ( 800 Vdc )
> supply?
>
> Tnx,
> Steve
> WA2TAK
>

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