Looking for two DEC H445 power bricks for PDP 11/40 project

Henk Gooijen henk.gooijen at hotmail.com
Mon Sep 17 14:30:53 CDT 2018

See answer below …

Van: P Gebhardt via cctalk<mailto:cctalk at classiccmp.org>
Verzonden: maandag 17 september 2018 19:54
Aan: General Discussion: On-Topic and Off-Topic Posts<mailto:cctalk at classiccmp.org>
Onderwerp: Looking for two DEC H445 power bricks for PDP 11/40 project

Hello list,
last year, I was able to obtain a BA11-F chassis for my PDP 11/40 build-up project. The power supply to run a system in basic configuration is complete except for two H745 bricks (delivering -15V) which are still missing.
I'd be very happy, if anybody could consider parting with one or two. Location is in Germany. Please contact me off-list.
Thanks a lot in advance for anybody of you helping me to work towards a running my first very classic PDP-11!
Best regards,Pierre

Pierre's collection of classic computers moved to: http://www.digitalheritage.de

Hi Pierre,
As far as I know, the 11/40 uses only one H745.
And vague memory seems te recall that the -15V brick is an “odd one”, because, unlike all other bricks, it needs the +15V from the regulator that is inside the H742 block. But I could be wrong ...

If you have a faulty H745, you can probably repair it. It is not too complicated, and when you have a +24 .. 30V DC power supply on the bench (and possiby that +15V DC) you can check the H745 out. It’s a secundary switcher, so safe to work on.
If you don’t have any H745, let me know. No promises, but I can check what I have on a shelf (probably defective, but as said, they can be repaired).

Henk, PA8PDP

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