1980 Lake Placid Olympics clock (ADRL Inc. "VistaChron", USA)

[@ElectronicsUSA]

What a great clock! It just has so much appeal going for it - great build quality, case design, color scheme, logo branding, and a unique display arrangement. I bet it was an executive quality gift from ABC to advertisers, agencies, station affiliates, etc... For many Americans, 1980 is probably the most memorable of all Winter Olympics too.

[@50sTransistorRadios]

Thanks! I'm really glad I bought this one, as I agree that it has a lot going for it, both cosmetically, electrically, and historically. I agree that they were probably used as deluxe gifts from ABC to important individuals that they worked with. The Lake Placid Olympics is the only one of the 1980's Olympics I hear mentioned these days, and I'm sure it was quite a spectacle for those who got to enjoy it live (a bit before my time).

[@misterhat5823]

A 40 year old clock was probably designed for a line voltage of 115V, not the 125V of today. That'd increase the bus voltage a bit. But... I've never seen TTL logic used without at least a 7805 reg as the allowed voltage is 4.75 to 5.25. The 5.5 you quoted is absolute max.

[@50sTransistorRadios]

I have since added another dropping resistor to bring the voltage down to around 4.75 volts, to preserve the displays. I suspect that the logic voltage has always been too high on this clock.

[@stevemar7952]

Cool clock. I've never seen those displays before. Thanks for showing it to us!

[@50sTransistorRadios]

Thanks! You don't see them too often, as they were mostly only used in aerospace applications.

[@michaelturner4457]

@@50sTransistorRadios Minitron type incandescent 7-segment displays were a common site in Gilbarco petrol pumps in the 80s, and right into the 90s. Think they used them, because they're easy to read even in bright daylight.

[@michaelturner4457]

I suspect it was made for ABC, probably for their studios and offices. It's definitely not a retail item. The mains cord without any strain relief and a grommet could be absolutely lethal.

[@50sTransistorRadios]

That's quite possible. Perhaps they were given out as gifts by ABC to certain important individuals involved with the 1980 Olympics, as ABC covered that one. I has since added a proper cord grommet, and a fuse.

[@VintageElectronicsGeek]

Matt - I have searched hi and low with all data offered, I could not find anything outside of mentioned sold item. ~Jack, VEG

[@50sTransistorRadios]

Thanks for digging into it, Jack! I suspect not many of these clocks were made. I wonder how many survive to this day.

[@Colin_Ames]

You always manage to find the most unusual clocks to show us. Please install a grommet on the mains lead before something bad happens, we’d hate to lose you!

[@50sTransistorRadios]

I've had some good luck with that lately. I have since added a proper cord grommet, a new line cord and a fuse, so it should be a little bit safer now.

[@misterhat5823]

Those caps are actually 2000 microfarad. For some reason the use of mfd, instead of uF, goes back to the vacuum tube days. The Si system wasn't in use then.

[@misterhat5823]

When a meter reads high on an old cap, it really hasn't gone up in value. The ESR is really high and that tricks DMMs that aren't expecting that into reading high. Replacing it was the right move.

[@50sTransistorRadios]

You know, I had been wondering that, and I'd like to test that at some point, but currently I don't have a good ESR meter. That's on my test equipment shopping list. I saved those original caps, and I "reformed" the better of the two caps on 25ma of current until it was able to reach it's full working voltage, and eventually the current dropped to near 0. It still measures over 3000uf though.

[@bblod4896]

I wonder if a current seven segment LED display would work in that clock.

[@misterhat5823]

It would need dropping resistors added. LEDs can't be tied directly to 5V.

[@bblod4896]

@@misterhat5823 1/8th watt should work well, small enough to hide them. I was focused on the pin-out. Are they the same?

[@misterhat5823]

@@bblod4896 I have no idea. You'd have to pull the datasheets of each device to be sure of the pinout.

[@50sTransistorRadios]

You'd have to make a lot of changes, since you would need dropping resistors (as mentioned) and the pinout would almost certainly be different. Not worth the trouble IMO.

[@JIMO415]

Well, I have the other one! It has found a good home. Hopefully the seller in between has done some of what you had to do. Too bad we both missed it the first time around.

[@50sTransistorRadios]

I'm glad you were able to grab it! The seller did mention that he changed the filter capacitors, and I wonder if the logic supply voltage will be as excessively high on yours as it was on mine. It alas would have been a lot cheaper from the original seller.

[@jastervoid]

I would be inclined to put a usb port on it to be powered by a 5v wallwart psu. Very cool clock. Would like to see a schematic for this 👍

[@50sTransistorRadios]

Thanks! I try to leave these clocks mostly original. I have since added a proper cord grommet, a new line cord and a fuse. As to a schematic, I unfortunately don't have one.

[@michaelturner4457]

Might be possible, but as this clock derives its timekeeping by dividing down the 60Hz mains line frequency, one would have to devise an alternative timebase source, like a quartz crystal oscillator with appropriate division.

[@ACURAOCULTA]

Very nice

[@50sTransistorRadios]

Thanks!

[@PINKBOY1006]

Guess what just got listed on ebay. You have another chance!

[@50sTransistorRadios]

I did see that, thanks! It's the same one that slipped by earlier, and it looks like it's seen as much use as the one I have.