Newport Laboratories 200A-3 digital panel meter (1972)
![Newport-200A-front.jpg](Newport-200A-front.jpg)
I bought these meters on a swapmeet. When I tried them at home, they seemed to work. At least, the displays light and say “000”.
I carefully dismantled one of them to see how it was built. It consists of two boards. The nixies, counters, decoders and control circuits live on one board. The power supply and analogue circuits are on the other board. The boards are connected by a ribbon cable of about 8 leads, carrying power and a few signals.
A look at the two boards, hinged open.
The A/D converter seems to be quite simple. The readout is not latched, so that the counting of the A/D converter can be seen. At least, so I presume, because I haven't put any signal to the input.
A look at the two boards, from the other side.
We'll see.
Copyright © 2014 by Onno's E-page published 2014-05-14