Beckman Berkeley decimal display datasheets?

[Robert Liesenfeld]

Hello-

This isn't strictly a Nixie topic, but I saw a conversation about this in a message thread in the Neonixie-L archives, circa 2002, so I hope it's OK.  I have acquired some Beckman Berkeley decimal display units with the goal of making a clock, and have so far been frustrated in my search for datasheets and schematics.  A couple of list members made it sound like they had copies, specifically for the 705AH/AJ/AK units.  Can anyone help me out here?

Thanks in advance.

-Robert Liesenfeld

[David Forbes]

Robert,

I think I have a Beckman counter book at home. If not, my brother Jim, who
frequents this list and had made a clock as you describe, certainly has some data.

http://www.selectric.org/tubeclock/index.html


--
David Forbes, Tucson, AZ

[J Forbes]

I have the 775 schematic, not the 705. it's on my web page as noted above.

It's been ten years...I forgot most of the little bit I knew about them.

Jim

[gregebert]

This device looks like an evolutionary step forward from the original Berkeley counter. It's been 40 years since I tore mine down for parts, but the photos look surprisingly similar despite this one being nixie-based and from a different manufacturer (HP).

https://www.ebay.com/itm/RARE-HEWLETT-PACKARD-DECADE-COUNTER-523CR-NIXIE-Tube-6-DIGIT-5963-VACUUM-TUBES/254584506524?hash=item3b466b489c:g:ISQAAOSwChhem-Tc

Disclaimer: I have no affiliation with the Ebay listing.

[martin martin]

Here's one I picked up at a local surplus house. I works well too, A few years after the one in your link

~

mcve...@gmail.com

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[Dekatron42]

There is at least a manual for the 705A and 705AZ modules here: http://www.bunkerofdoom.com/ serach for Beckman and you'll find the 5500 EPUT meter where there is a schematic and explanation of the whole unit.

These units are similar to the Hewlett Packard HP-4A series of modules, I'm not sure if they are pin compatible and would work if you swapped them for each other, but the design is very similar.

/Martin

[Mac Doktor]

Before I reply, I want to add that I used to have a five decade HP decimal counter with *incandescent* light bulbs instead of neon lamps. I assume it was a last generation model before they switched to those new-fangled Nixie things. I got it at the end of the day at the Manassas hamfest circa 1995. One numeral was out and the culprit was a bad transistor. IIRC, it was in a TO-5 can and a 2N3904 fixed the problem.

Unfortunately, it mysteriously disappeared after a small flood in the basement. I wasn't home at the time and there was a major clean-up during my absence. The funny thing is that nothing else was missing. It was stacked in the middle a small pile of gear all of which was still there but rearranged.

The upshot to all of this is that I would REALLY like to have another one but the few that have turned up on eBay recently were/are too rich for my blood or got snagged by some other bargain hunter before I had a chance.

On Jun 2, 2020, at 2:43 PM, Dekatron42 <martin....@gmail.com> wrote:

There is at least a manual for the 705A and 705AZ modules here: http://www.bunkerofdoom.com/ serach for Beckman and you'll find the 5500 EPUT meter where there is a schematic and explanation of the whole unit.

Thank you for that. I have a 705B (with tubes) sitting next to my computer.

These units are similar to the Hewlett Packard HP-4A series of modules, I'm not sure if they are pin compatible and would work if you swapped them for each other, but the design is very similar.

Searching for those right now...

Terry Bowman, KA4HJH

"The Mac Doctor"

https://www.astarcloseup.com/

“The book said something astonishing, a very big thought.
It said that the stars were suns, only very far away.
The Sun was a star, but close up.”—Carl Sagan, Cosmos, 1980