The Avo Meter, as in Amps, Voltage, and Ohms, was a multimeter made by the Automatic Coil Winder and Electrical Equipment Co. in London. The first Avo Meters were produced in 1923.
This is the Model 8. My Dad gave it to me. He’s had it forever. Another vintage goodie rescued from the garage.
The Model 8 saw 7 version changes in its lifetime. (Model 8 MKII - Model 8 MK VII). The Model 8 began production in 1951.
An ad that I found online showed that the price for the Model 8 was £23 in 1953. I won’t go into exchange rates because it’s irrelevant knowing what it is in dollars. The important thing to realize is that in 1953, £23 was more than two week’s salary for the average Joe. Adjusting for inflation equates to about £1300. They were pretty top-of-the-line. They were well known for their durability and feature set, as well as being the only model with a mechanically operated cut out.
I removed the top cover to see what kind of battery it takes. Yikes! What’s that?
The “SP2“ is a regular 1.5V D battery…but the other one is a weird 15V cell. Believe it or not, but they actually read 1.39 and 1.9 volts! Why are they not 0 volts?
Much to my surprise, the 15V B121 battery is still very much in use today. If you can’t find one locally, a quick hack is to roll up 10 x 1.5V coin cells.
There’s a few cracks in the case originating from the screw holes.
Besides the cracks, there’s a pretty hefty layer of dirt.
Ok, let’s see what I can do about cleaning the enclosure. I started by removing the metal panel on the back.
I took out all the screws from the sides and the back cover came right off.
Wow, look at that! This thing is right out of Dr. Frankenstein’s lab.
Look at the size of the resistors. They’re like AA batteries!
The inside of the back cover was pretty nasty.
I took a paper towel to it with some rubbing alcohol and it came right off. Pretty gross stuff.
I did manage to take the dial out. I didn’t want it to get wet during cleaning. I also wanted to take the glass out to give it a nice cleaning with some glass cleaner.
Interesting fact: You can tell the date of when the meter was made by looking at the serial number. The last digits “661” means that this unit was manufactured in June of 1961.
I cleaned the front with some rubbing alcohol and a toothbrush, as well as some Q-tips. It’s orders-of-magnitude better. Here’s a before and after image split down the middle:
After several hours of elbow-grease, I got the enclosure nice and clean.
Looks almost new!
I screwed the metal back plate back on to the case and reattached the leather strap.
I then screwed the whole thing back together. Not too shabby.
The unit does’t work, and the dial isn’t calibrated...but at least it looks nice! At least it’s not in a landfill somewhere.