Betalerts In the Attic

While rummaging around in the attic this past weekend looking for a Betalert 10B user's manual, I stumbled (almost literally) across an old Betalert unit that I had forgotten I had. I was pretty sure I had my original prototype up there somewhere, but this unit I found was not that unit. My prototype is easily identifiable because the front panel is completely unpainted. It is just brushed aluminum with no LED legend plates on it. But, as you can see from the picture below, the unit I found looks like a real unit.

After thinking about it for a few minutes, I began to have vague recollections that this was a demo unit that had been put together for one of our salesmen to take out the road with him. Note that the legend plates are not screwed on, but are merely glued on. I can't remember why the unit was put together that way. I guess he needed it in a hurry and couldn't wait long enough for someone to go find the screws for him. Anyway, at some point he got a production unit and no longer needed this unit and was going to toss it. Fortunately, I found out about it and appropriated it.

I can't remember if it works or not, but I guess it doesn't really matter. I saved it from the dumpster mainly for looks and not because I needed a functional 10-point LED annunciator.

As you can see from the sticker below, it is serial number 52107. Color me skeptical. This unit was more likely among the first ten or twenty units we produced. But I think they picked the starting serial number to be something higher than the last serial number for the Betalert 10A, which was being phased out. So, on second thought, I guess such a high serial number is not too outlandish.

There is a date stamp on the bottom of the printed circuit board that indicates the unit was built around July 29, 1987.

The printed wiring board (PWB) has a revision of A, so this is my second pass at the design. I'm not sure what I fixed, but I know that this was not the final revision of PWB because the oscillator footprint had not been fixed yet. When I originally laid out the PWB, I somehow managed to get the holes for the oscillator leads just a hair too close together. Believe it or not, that was about the only mistake I made on the PWB. Considering that this was back in the days when PWBs were laid out using black tape on clear Mylar, that wasn't too bad!