EEVblog #1138 - Systron Donner Counter Teardown

Teardown Tuesday
An early 1970's Australian made Systron Donner Nixie tube display counter/timer.

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[diabolicalartificer]

Sent you an PM Dave via the forum regarding a manual. I love the build quality on this vintage test gear, it's very similar to HP stuff of the same era. I had a HP3770B telephone analyser that used the same construction, IE horizontal bottom bus board with vertical cards, it used the same type of plastic clips to secure the card, heavy gold plating, etc..
Thanks for another cracking video.

[TheDefpom]

The ovenized oscillator heat has probably killed the multi turn trimmer inside it, I have found that the heat tends to make the plastic go brittle and they break when turned all the way to the end, pull the oven apart and replace the trimmer, I have done this myself on a Marconi 2305.

[DrakkarCalethiel]

Those Nixie tubes just look beautifull!

[spnrx]

I was working in a major electronics plating plant in the 1972-1973 years and gold was about $45 US an ounce. We didn't plate cicuit boards but did plate *millions* of IC lead frames monthly. Generally, the gold plating was from 15 to 40 microinches thick. We also plated flat wire for Sprauge that had a (IRC) gold plating of 200 micrroinches and another flat wire, silver plate of 350 microinches. We plated *miles* of that wire.

Just thought I'd add some relevent historical info....

[anachrocomputer]

Did you notice the big blue edge connector alongside that big row of 7475 latches? And there's a gap in the metalwork of the chassis just behind it, leaving a clear path to the rear panel. On the rear panel are blanking plates for the digital output connectors (optional). So my guess is that the edge connector is used to connect to a PCB and/or wiring harness that leads out the back for the digital output interface.

Also, the RECYCLE RATE control was set to 'infinity', which is why Dave had to keep pressing the RESET button to get a reading. Turning that rate control clockwise would make it auto-refresh.

[apbosh]

Wasn't sure whether to watch this one but glad i did. Great teardown and the display is very nice. enjoyed every minute.

[andycristea]

Beautiful, Dave! Thanks for saving and sharing it!

[WacKEDmaN]

thats an impressive amount of gold...but its a thing of beauty! it needs to survive for Sagans kids to see!

[bobweiss]

Taking the "recycle rate" pot off the "infinite" setting will prevent you from having to hit reset for each gate...

[CoolMusicToMyEars]

I agree Dave, Systron Donner are very well built inside, not a well known popular name, but I have used the frequency GHz counter of Systron Donner and they do work very well,

[karlomoharic]

you have to appreciate the effort that has gone into designing this product :)

[merseyless]

I have that EXACT same model up here in Brisbane, except that the gate is stuck high. Bought the service manual for the model down from a bloke in the USA for $70 plus shipping. Only difference between the two models is the A12 and A16 modules. Fun fact, the A12 module handles the gate! If you have any manual/schematics for the modules I'd love to see them.

[simontay]

You' re right, they certainly don't make them like that anymore. It is absolutely beautiful.

[hzmeister]

this is waaaay before my time, but it's always interesting to see how they did things without a computer or any of the tools we have today. well laid out boards from back in the day really are a work of art.

[NenadKralj]

I need to say that this is the most beautiful board layouts / colorful / easy to see what I ever see so fare (: I like it !!

[petroldevo]

I bought something similar from an electronics surplus store. The front of that device looks very similar. I only bought the thing for the nixie tubes and drivers. Cost me 25.00 dollars. It actually worked. Very cool vintage!

[Herby-]

They used a combination of 5V DTL and 5V TTL for the unit. I suspect that the TTL is used in the "high speed" part of the unit. DTL was a predecessor logic but was rapidly replaced by TTL. By 1970 DTL was very out of favor, and probably not used in new designs. TTL had more MSI parts, especially the 7490 decade counters used. Just a bit of history.

[Tedd]

17:50 I can't be sure because I don't have the same machine, but I'll bet that you can use the extender card for all boards in the unit. The shorter and longer daughter boards have the same number of pins and the extender has all keys cut into it.

[joeybushagour]

Man, something about 1970s tech. Absolutely gorgeous

[hanro]

My university still has a massive bit of tech from systron donner sitting on display near the main entrance.

Also found a machine labelled "Applied Dynamics International AD 100". My university is the university of Stellenbosch in South Africa and the specific building is the engineering building.