Multimeter Manual or Battery Type

[NViousGK]

I am definitely new to these forums, and have specifically signed up because of one piece of test equipment I own. It is a Micronta 22-205 multimeter made by/for Tandy/Radio Shack back in 1975. As a precaution and prelude to posting this thread, I followed the instructions for new posts and looked in all of the links provided. I performed litterally a dozen or more Google searches to no avail.

To be frank, all I really need to know is what batteries the meter takes. One is a standard "C" cell, but since the other battery is currently missing, I cannot simply match it up to buy a new one. I believe the right one is:
22.5 volt 15F20 22.5V Carbon Zinc Battery 412 U15 VS084 MN122
as listed on E-Bay, however I'm not made of money, so I don't want to spend the cash only to find that it is the wrong one.

I would prefer to locate a PDF manual, but barring that, simply knowing which battery to purchase will be a great help.

Thanks for reading.

Cheers

 

[(*steve*)]

I don't suppose you tried googling for "Micronta 22-205 batteries" did you?

Because the first hit has a site with links to all the manuals.

And I'll even save you the google search...[Which was wrong]

 

[NViousGK]

You almost had me excited... But alas, not quite.

The page you pointed me to is also the same one that seems to pop up over and over again too, but they just don't have anything for MY multimeter. Even going deeper into their site brings up nothing for me I've run into everything around it, like the 22-204 A,B,C AND D. The next one up in the list should be mine, which is the 22-205, but it get's skipped over and the next one I find is for the 22-210, which again, is just not the same.


I have a pic, would that help? It's from an original Radio Shack catalog ad, but it should be good enough.

I truly apreciate the help though.

T

 

[(*steve*)]

Bugger!

 

[NViousGK]

Hahahaha. Don't worry, it happens to us all

You gave a lot of useful information in your post that lead me to the right Google search.

Sorry, I had to edit my previous reply. I'm still unable to locate the 22-205, or anything about it. The calibration doc was pretty cool, but it's just not what I need. E-Bay came close too. Still, no cigar.

Am I missing something, or is Google doing that thing they do where they profile you and give you what THEY think you want?

Sorry guys and gals... I am definitely confused on this one.

 

[(*steve*)]

Yeah, I was in a hurry at the time and didn't notice the "sponsored links" message.

Show us more photos of the device. An interior shot of the battery compartment would be great.

 

[ModemHead]

empirical method

Do you have, or have access to, a variable DC power supply? You will also need a one megohm resistor (brown-black-green). If so, the nominal battery voltage should be easy to figure out if the VOM is otherwise functioning correctly.

Set the VOM to the highest Ohms range. Set the Ohms zero-adjustment about midway. Connect a one megohm resistor to the VOM test leads. Set the power supply for minimum output and connect it to the battery terminals, observing polarity. Dial the voltage up slowly until the meter reads one megohm. (ie. the meter reads "10" on the RX100,000 range.) The power supply voltage should then be very near the nominal battery voltage required.

Side note: I have a slightly older 30Kohm/volt Micronta VOM that requires a 15V type 504 battery. It is no longer accurate, but I keep it for sentimental reasons, since it was a gift from my parents for my 12th birthday.

 

[NViousGK]

Unfortunately, I don't have a lot of the equipment I had oh, so long ago. Idiot cousin - Long story!! However, I was able to verify something. I don't know if this helps you. It didn't help me much.

The Micronta 22-205 multimeter is almost identical in appearance and operation as the 22-207! The only difference I could see is that the 22-205 has much more silver (aluminum) than that of the 22-207; which is almost entirly black with silver lettering/legends.

There is also a white ink marking on the outside of the battery compartment, but I don't think it's of any value. You can see that marking in one of the pics I attached.

On the bright side, I think I may have narrowed down the search to a single bettery. Here's a link to one (pair) on E-Bay. I seem to remember this battery/meter combo while working at Radio Shack at the Dawn of Mankind from 1975 - 77

http://www.ebay.com/itm/2-15F20-22-...2-U15-VS084-MN122-/220781419843#ht_1057wt_810

Thanks again.

On another positive note... My Simpson 260 series 6 will be delivered today!

 

[ModemHead]

The only other thing I can think of is to connect two fresh 9V batteries together in series. That should give you about 19V. Connect them to the unknown battery terminals. If you can adjust the zero control to get full-scale or almost full-scale deflection in the Rx100K range with the leads shorted, then the 22.5V battery is probably correct. (Expensive little bugger, isn't it?)

If the needle wraps itself around the peg, then it's too much voltage.

 

[NViousGK]

Expensive? Yep. But not as expensive as buying a Simpson multimeter. Mine just arrived It's a 260 series 6 that I paid $69.99 for. At least it takes standard batteries. But I'm still going to go for the battery for my Micronta. I have a history with those. Ultimately I really want a Micronta 22-220, Radio Shacks "Professional" model that came out in around '78 or '79. But those things are more expensive than the Simpsons!

 

[ModemHead]

Congrats on the 260. By the time I could afford a decent multimeter, the world had gone digital. But I do remember using a 260 at work. I recently picked up a Triplett 630 in mint condition for $18, just for old times sake. The 5KV range actually came in handy recently while troubleshooting an oscilloscope. Otherwise, I'm all digital here.

I've seen that Micronta 22-220 on eBay. Looks very Simpson-ish. Good luck!

 

[NViousGK]

Thanks. I'll take all the luck I can get if I could get the same deal I got on the Simpson. I haven't even gotten it out of the box yet, because I've been so busy at my keyboard all morning long. But, that's next on my list.

 

[ModemHead]

Well, here you go for $25, shipped: Micronta/Radio Shack Multimeter Tester With Carrying Case

 

[NViousGK]

Yeah, I saw that one too. E-Bay can be fickle though. And so are the sellers. There is a lot more wrong with this meter than the seller is stating. Besides, after funally unpacking my Simpson, I'm extatic! After a bit of cleaning with solvent to remove sticker residue and replacing the "D" call and STANDARD" 9 volt battery, my newly acquired Simpson 260 is in "LIKE NEW" condition. Even the battery compartment looks like new! I can't believe the deal I got on this meter.

I'm still going to buy a battery for my Micronta. It's a nice meter. Maybe a bit later I'll post a side by side comparison picture.

Vintage electronics, specifically Vintage computers as a hobby has been extremely good to me. I own a beautifully kept IBM 5150 circa 1982, WITH an IBM 5161 expansion unit, IBM 5152 Graphics printer, IBM 5153 CGA 16 color monitor etc. The thing that makes my installation so rare is the inclusiion of the expansion unit. There are litterally less than a dozen left in the World in working condition, and I have one. The best part is that I have absolutely no out of pocket expenses. It's only been about 15 months since I got started buying the first part of the system too.

So, yeah, I've been super lucky. The Simpson meter is no exception. I still don't have any real out of pocket expenses.

How? I post ads in Craigslist looking for old computers. Most people will give them away freely. Once in a while, something will pop up that's worth a bit of money, but regardless, it's all sold either as vintage gaming computers or, as in the case of an Apple lle, it was worth over $200.00 to someone because of the duodisk drive. There's a lot more to the story, but I'll get into that at another time.

 

[Toolkitguy]

22-205

Have this meter. It's a 15v type 504. Used only on the 100k scale.

 

[nepow]

multimeter ID

Brings back memories, I had one of those multimeters which looked identical to your pic, however I can only remember seeing one battery. The 22.5v batteries were commonly used for analogue meters... similar size to 9 volt stud topped cells but with their connections at either end. I got rid of it after discovering the battery had leaked internally, but often wish I still had it to hand, Bugger again!!