[Heathkit] HP-23(*) differences.

[crawfish]

Ken, I have a chart showing the differences in the variants of the HP-23
that I ca email to you or anyone that wants one.
                                                              Joe W4AAB
----- Original Message -----
From: "Kenneth G. Gordon" <kgordon2006 at verizon.net>
To: <Heathkit at mailman.qth.net>
Sent: Tuesday, May 08, 2007 12:50 PM
Subject: [Heathkit] HP-23(*) differences.


> Well, another problem I have discovered: I have two HP-23(*)
> power supplies, both completely rebuilt with all new diodes and
> filter caps.
>
> One model is an early model of HP-23 (no suffix) while the second
> one is an HP-23B, two models later.
>
> I installed a DPDT-Center-off toggle switch in the HP-23 to enable
> easy switching from 250 to 300 VDC for the LV as is done in the
> HP-23B and others, and have used it for over a year with my HW-
> 101 and have experienced no problems whatever.
>
> However, I have always felt that the HV was low in the HP-23,
> despite the fact that it runs cool and works fine in every other way.
>
> Recently, while restoring a basket-case SB-102 to operation, I
> discovered that the HP-23B's HV output is around 800 VDC, even
> under load, while the HP-23's HV output is below 800 VDC at no-
> load, and drops to around 725 VDC under full-load. The difference
> is almost 100 VDC.
>
> Does anyone know whether or not Heathkit uprated the power
> transformers in their later model HP-23(*)? It sure looks like it to
> me!
>
> Ken Gordon W7EKB
> _______________________________________________
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
> $$ See the vintage area on the HCI web site - http://www.w9wze.org $$
> Heathkit mailing list
> Heathkit at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/heathkit
>