Tubes in a Sperry Remington 1213 calculator

[Paolo Cravero]

A bit of introductory story. The question is after the pictures you want to skip to the end.

While wondering around a thrift/second-hand shop I spotted in a corner in the "electronics" area an old-looking calculator, on display in its original polystyrene box. I looked through the display window and saw something not VFD-like. While holding one hand on the device (so that nobody would "steal" it ;) ), I looked up on google images the model name: "Sperry Remington 1213". Not much info online, but enough to see that the calculator has 12 indipendent display tubes. No mention to brand/name. I could tell they're 7-segment.

Even if the price was right, I asked the attendant to power it up. Oddly enough, it requires the three-pole standard computer cable. All segments lit up. Yeah! I even got a reduction because it had been there for more than a year, and I had not seen it before! I must dig a bit more through all those 1980's audio equipment!

So, here she is. It has the dust cover too!

See the odd half-height "zero" that seems to be typical for Remington devices:

And a close-up of the tubes, from outside:


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Is that an anode mesh? I am reluctant to open it just yet (someone else did it at http://www.alciom.com/perso/calc/sperry-remington/1213/descrcalc.htm), so here I ask: what display tube is that?

Another unusual arrangment is the use of reed contacts under the keys.

Looks like I'm going to build another calcuclock (my first attempt is on my desk at work https://www.youtube.com/watch?v=erOKpK8YA20 apologies for the lousy video quality). The problem with these perfectly working old devices is that their AC "safety" is not compliant to recent standards, so they cannot be used in work places or the insurance would not pay in case of fire. That said, I trust more a 1970's calculator than most modern smartphone chargers.

Thanks for reading,

Paolo

[Tomasz Kowalczyk]

These are definitely VFD tubes. The mesh seen on the photo is the grid. I think no other display technology would have this wonderful greenish blue colour.

I tried googling it too. I think these might be LD8035 tubes.

On this site there are good quality photos of the interior.

http://www.alciom.com/perso/calc/sperry-remington/1213/descrcalc.htm

[Tomasz Kowalczyk]

Oh crap. You've linked that page already. 

[Robert L]

I noticed there's one of these calculators up on eBay If anyone is desperate to try their hand with this calculator...

http://www.ebay.com/itm/Vintage-Sperry-Rand-Remington-Tube-Calculator-Model-1213-Vintage-TESTED-WORKS-/131948714335?hash=item1eb8c1995f:g:QgsAAOSwmLlX5Zei

 

[Paolo Cravero]

Thank you Tomasz!

Indeed, their color is peculiar and hard to capture in a picture (let alone screen color calibration on the viewing end). Those LD8035 tubes (search for LD8035E) do not seem to be readily available, at least not on webpages written in Latin alphabet. But Japanese do: http://iizukakuromaguro.sakura.ne.jp/422_vfd/422_vfd.html . There are more pages and more interesting single-digit VFD tubes over there!

Their current NOS price seems to be between 1 and 2 USD. The buyers' competion is between "us" and calculator collectors :-) I am glad I got it at "total tube value" rather than "collectible value".  I will write an email about a calculator with one more interest group in the next days.

Paolo

 

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