Neon Digital Tube Clock

[J Forbes]

I made this clock around 2002, and made the video around 2008.

https://www.youtube.com/watch?v=VM9TW6GcCQE

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

I probably need to update the web page! But anyways, the clock quit working not long after I made the video, and has just sat doing nothing. For some reason I brought it out into the light a couple days ago, and started messing with it. The counting was not working, it would sometimes show movement, other times just sit stuck. I poked and prodded and noticed it would sometimes start working for a little while if I wiggled one of the four tubes in the input circuit (which turns the sine wave of the line voltage into a 60 Hz pulse). I realized I could try substituting tubes, and see if it would make a difference. The third one I tried, did the trick. The 6U8A seemed to want to be replaced, it started counting just fine.

Then I decided to see if I could fix the setting issue. When I was working on the clock originally, I decided to make it into a tall obelisk case, but never got around to actually building the case. To make it fit, I extended the wires from the main unit to the Hour/Minute display unit, and it has always been finicky about setting time since I did that. I decided that maybe it could fit in a smaller case now, so I shortened the wires, and now it works great. I can set the time easily.

It's been running for a day and a half, keeping good time. But it sure does get warm, with 31 vacuum tubes!

Anyways, hope all of you are doing well, and enjoy my little blast from the past

Jim

[gregebert]

Oh my, I recognize those counting modules. Around 1980 I bought a surplus "Universal EPUT Meter" manufactured by Berkeley (apparently a division of Burroughs) for $1 US. So many vacuum tubes.....  I had thought about making a clock out of it, but the display was too hard to read in my opinion. I scrapped it for hardware, neon bulbs (many of which I still have), and tossed the rest. I hate to admit this, but I had a lot of fun throwing the vacuum tubes in a storm drain and listening to their "pop....tinkle.....tinkle" sounds as they imploded.

The main reason I scrapped it was that I already had a nixie-tube frequency counter, so I had no use for the instrument.

I'm attaching a product brief from 1956 that I found online. Enjoy.  

[gregebert]

I also remember 2 variants of this type of display. The one pictured shows all of the digits in a single vertical line, which is easiest to read. But there was another style that had the bulbs staggered, and they appeared to zig-zag while counting. I thought it was really annoying. But this is an important bit of history, because I'm certain this led to the development of the nixie tube.

[Mitch]

That is really great!

[J Forbes]

On Wednesday, September 2, 2015 at 7:37:24 AM UTC-7, gregebert wrote:

I'm attaching a product brief from 1956 that I found online. Enjoy.  

neat! That reminds me...I also have one of those 1950s looking berkely counters. It's actually a 5510C Universal Counter and Timer. This is one that I played with almost 15 years ago to  try to turn into a clock, and never got the 12 hour module figured out. But it does sit and count time still, although it seems to have some trouble with one of the 0-5 modules skipping a few counts every now and then. It's still complete, although modified. It has the old blue enclosed modules like in your brochure.

It had been sitting in my basement undisturbed for over a decade, until tonight.

http://selectric.org/tubeclock/5510c.jpg