I’ve been playing with my NOS Midland tester. It’s the one on right. As an example, I also included the photo of a Micronta meter. You will find a number of similar models with slight differences. Notice the batteries are still in the wrappers. While removing the back, a red tag fell out that stated, “Remove the red wire before installing batteries.” The red wire was connected across the meter terminals for protection. No doubt this one has been sitting on the shelf untouched for the past 50 years. I almost forgot about similar one I had years ago. At present, I only installed a new AA battery. The odd sized 15 volt battery is only used in the 10K ohms position. Everything else will work fine without it. At this point there are three 15v battery choices; roll your own, convert the meter to except a standard 9 volt battery, or buy a W-10 15v photo flash battery. An Eveready 504 or NEDA 220 photo flash battery runs around $13. I’m treating this nostalgic treasure with kid gloves, so I doubt I’ll do any radical conversion. I have compared some measurements that I’ve taken with my digital meters. So far they are spot on with all my DC and Ohms readings.
The meter came with a very small manual with schematic that is in pristine condition. I scanned it to an easy to view resolution.
The meter came with a very small manual with schematic that is in pristine condition. I scanned it to an easy to view resolution.