- 2024
- Dec
- 11
The 1970s live in this Elenco M-1200 meter.
I didn’t need this device, but it came home with me as part of my “Can’t leave the hamfest without a voltmeter” program…It came from Fort Wayne and was a couple of bucks.
The real reason I picked this up is because of the design. This is so 1970s it hurts, although it probably was made in the 1980s. It’s a simple DMM and offers all of the things you’d need in a meter.
The device can run on batteries or external DC, as evidenced by the back. No mention of the required voltage, however, and the device is old enough that a headphone jack is used instead of coaxial for the power input. Since the device has 4x “C” cell as it’s internal supply, I’d assume the external power should also be 6V.
It’s woodgrain all around.
Inside, there’s not much. A power supply board with some circuitry for the meter, batteries, and the business end of the device (under the front panel.) Without the batteries, this thing would be quite light.
Here’s the main board. It’s most certainly an ICL7117 based device, as evidenced by the big DIP in the middle.
But does it work? I hooked it up to a nearby USB charger device, and it did read - although the decimal point was flaky. I had to wiggle the switch a little to get it to show up. (The 7117 is a simple 3 1/2 count ADC with 7 segment output. It’s up to the user to scale it and provide decimal points.) I didn’t check the unit for accuracy, just operation. I did notice a segment seems to come and go as well, so maybe some solder joints are cracked. Who knows.
What’s going to happen to this? If it’s accurate, it will probably go in my rack as a rail monitor. Otherwise, it’s just a cool piece of old tech.