(OT) Heathkit and Nixie Tubes


Recently, we've had topic threads on both Heath kits and Nixie tube displays. In digging around the net, I found a kit from KABtronics called the Nixie-Transister Clock Assembly Kit. It uses no IC chips, only transistors, diodes, resistors, capacitors, etc. and the display uses Nixie tubes. It just arrived today and it's very cool. All the parts along with a complete instruction manual are included. Some assembly is required. :^P

Following this forum costs me way too much money...



Some assembly... Yikes!

Link here.


Nice big PCB with lots and lots of soldering to be done. But I don't like those Russian Nixie tubes that use an upside down '2' instead of a real '5'.


Yeah that's what you need ... nixie tubes to keep your place warm. I just like they way they looked. ;-)


Hello to you all,

The link to KABtronics appeared in this forum for the first time, 2 or 3 weeks ago. I jumped on it and ordered the LED Transistor clock kit. It's a real joy for a (real) geek. I'm in the process of building it, by now 400 out of ~1200 components assembled, 950 solders out of ~2800 done and yesterday I saw the first digit displaying seconds from 0 to 9... what a fun.

Just my 2 cents,

Edited: 1 Dec 2011, 1:02 p.m.


Congratulations! Many hours of fun ahead :-)

Not nearly as fancy, that's kind of a poor man's digital clock kit I assembled years ago:





A co-worker gave me two printed circuit boards that had come with an electronics magazine. I gathered the required components and assembled the kit, but I was soon disappointed as there was no backup batteries to keep the correct time when AC went off. So I rebuilt the main board and added a secondary board to provide an alternative 60-Hz clock signal. One transistor switches off the LED displays when power if off, the other one triggers the 555 IC. The tiny board that holds one diode and two resistors switches off the two blinking LEDs (I'd forgotten about them). Still working! :-)


Edited: 30 Nov 2011, 6:59 p.m.


A 555 timer! I remember those from the Apple ][ days...it was used for the joystick input circuit on the ][...

Do they still make 555 timers?


Yes, "the part is still in widespread use":



The joystick circuit used a 558, which was a quad timer that was vaguely similar to a 555. Some people call it a quad 555, but it isn't really.


My Nixie!

simple 60Hz timing system off the house mains

and of course the Nixie watch:

Cheers, Geoff


Is that radioactive hazmat sign for real?


Knowing Geoff, the sign is real, the hazard is not. His humor is a near-mathematical constant and an asset.



Nice way to put it Jim.

As of yet, I have not used the buggy ROMS but fully intend too. Thanks for them, Jim.

Cheers, Geoff

Also the clock above uses Russian tubes. You can tell because the 5 is an inverted 2. Saved steps in the production line.

Edited: 1 Dec 2011, 12:48 p.m.


LOVE this watch! Two digits?


Has a settable tilt setting and a 24 hour setting.

tilt the watch to view and it displays in a series of flashes:

- first flash hours
- second flash minutes
- third flash seconds; displaying up to 30 seconds at a time to
save power.

6 volt lithium battery stepped up to 150V to drive the display with a step back to 130V (by memory, should check the site) to continue the display. Well check out the site:

Nixie watch by Cathode Corner


What is the link for the desk clock or did you design it yourself?


You have mail!

also kit or built:

clock link

Cheers, Geoff


His The Nixie Watch from Cathode Corner site also has a link to his personal site:

Welcome to Cathode Corner

That's where I found a link to a handmade calculator that his friend made:

Homebrew Desk Calculator

That sure takes me back to home projects I was involved in and the self made PCBs to solder parts to.


6 volt lithium battery stepped up to 150V to drive the display

Nothing like 150 V on your wrist to deter muggers! Put a few exposed prods on it, and open up a whole new market.


hard enough getting through airport security without having a Taser label included.



I like the look of Nixies as I worked with them a lot many moons ago. This clock also runs off of 60hz mains but I recently heard that the power grid is not going to maintain the strict 60hz standard as in the past so clocks dependent upon AC power will not be as accurate. I suppose with WWV and GPS clocks, it's not so critical but that bums me out.



They will stop the night-time "catch-up" to compensate for lost cycles during daytime.
But for what I read, the inaccuracies introduced will be very small, especially considering that you would loose the time setting anyway at every power outage...



Then I'm plugging it into my PC UPS! With all the winds around here in LA today, I'm lucky to have any power.



Hehe... I have my power-network-synced clock on an UPS too... but my point was that the UPS's frequency isn't precise at all, surely much less stable and precise than the network, even after the recent "degradation"! :)



Doing the math and assuming LA has a really crappy control of there electrical system, lets assume an accuracy factor of only 98% (58.8Hz/60Hz): that is a the system runs at 98% of 60 HZ all day! Of course, the system is described at the LA web site as

"Power Quality refers to the characteristics of the power, or specifically the current and voltage, provided to the customer. The power is to be provided in clean sinusoidal waveforms at a frequency of 60Hz that does not contain sags or spikes, which allows the customer’s equipment, including sensitive electronics, to operate reliably."

(1) 60min*24hours=1,440min/day

(2) .98*1,440min/day=1,411.2min/day

yikes at a whopping 30 minutes a day!

However, I would suggest from the little research I have done on the LA power grid, the system runs better then that, and that spikes probably serve to cancel drops in the 60Hz as the system does not consistently run 'off' 60Hz.

In anycase, here in Vancouver I am off a minute to two per month during the windy season in November.

Cheers, Geoff

LA power home site

interesting article on waveform and distortion


Hey Geoff;

Yes, that's my concern, accumulated error. This kit has a backing plate and I'm planning to put it on my garage wall (The garage has been finished. Sort of my mancave. My wife would never let that clock in the house!) but it will be above my desks and a little hard to reach. So it will accumulate errors over time which will require periodic tweaking. I could find an old HP Cesium standard down at the TRW swapmeet and take the 1PPS output to drive the clock. Is that overkill? :^)

At work, hi-freq harmonics on the AC main's neutral line can be an issue. All of our broadcast equipment use switching power supplies which puts lots-o-crap on the neutral line so there is a special transformer (K-factor? I don't remember.) to filter it out. When we use our Fluke analyzer to look at the AC mains there's always a lot of crap on the hots (that's after the 750 KVA APC UPS down on the first floor) but it all works.



I could find an old HP Cesium standard down at the TRW swapmeet and take the 1PPS output to drive the clock. Is that overkill? :^)

I've looked into that kit as well... but (also since I have 50Hz here, not 60) I was planning something less dramatic: just the 1pps pulse from a cheap quartz clock would do, I think, and could be easily hidden behind the main board, and powered from the same supply or from a simple AAA battery... Then the only issue would be how to make it keep tracking time during power-outs. I haven't figured that one out yet, besides using another UPS!



...I could find an old HP Cesium standard down at the TRW swapmeet and take the 1PPS output to drive the clock. Is that overkill? :^)

This is overkill :-) Most Accurate Nixie Clock

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