AVO Multimeter survey

[Superscope]

Thanks Mike,

Does anybody else know anything about this Meter?



Ian

[pmmunro]

This is one of the Multiminor varients which I mentioned in post 2347 where I posted serial numbers.

Would it be best to give more detail here or would it be better to start a new thread so that anyone looking for information in the future will find it more easily?

PMM

[Superscope]

PMM,

That's a good question.
(PM sent by the way).

For the purposes of information, like an overview,
Photo's and general discussion, I would have thought
this was the right Thread.

This certainly forms part of the Wider Avo Multimeter Survey subject.

Regarding finding this information later, this Forum's Search Function doesn't
seem to distinguish between different Threads as far as I have noticed, so it
will be found just as easy here as anywhere else.

I guess the Moderators will decide if they think this is not the right place.


Ian

[AndyGilham]

A few more meters have been donated to the Megger collection

Avometer Model 8 Mk 3 107785-1169 (November 1969)
Avometer Model 8 Mk 3 93490-269 (February 1969)
Avometer Model 8 Mk 4/9Mk 4 - No Serial Number
Avometer Model 10 00165 10/7/77 (July 1977)

Andy

[Electrical]

I have just been reading about the International Rectifier Zener diode Tester and having just found mine, I have taken a few pictures of it, please see attached.
The serial number is 210-763.
I any one would like a PDF copy of the manual, I can scan it and clean it up and posted hear.
Regards Stan.

[micheal]

Hi Stan,

I would very much like a copy of the manual.
It looks like they were all made in July 1963 so far.

Many thanks Mike.

[pmmunro]

I have a scan of the manual which I'll post later today.

PMM

[Electrical]

Hello Micheal
Please find attached a PDF copy of the AVO International Rectifier zener diode selector working instructions, parts list and circuit diagram.
Note the PDF copy is 200% bigger than the original.
Regards Stan.

[Superscope]

Many thanks Stan,

That's a really nice Meter you have there.
I didn't expect to see one in such good Condition with Case and Leads.

The User Manual is a nice Bonus.


Ian

[micheal]

Hi Stan,

Many thanks for PDF copy of manual.

Mike

[JohanBee]

Hi folks, I’ve come to own an AVO-meter type 21-S (the S probably for the Swedish edition) dated 1972.

It originates from the Swedish Navy former spare stock, is never used and contains all accessories including the old batteries in the original case.

Is this a collectable item that should not be used or can I start using it, as I have no good analogue meter at the moment?

I just ask this from you specialists out there to advice me. I’m not in need to use it if it’s a collectors item that should be kept unused, but I’m myself not a collector of instruments.

It has been in to regulary check at the Navy depot service dept, last time in 1979, so it have some minor scratches from handling there.

I attach some photos of it to judge and give a wiev of the Swedish Edition backside instruction plate, delivery note and Navy inventory markings.

[The Philpott]

My own opinion...
Collectable? Yes.
Rare? probably.
Use it or put it in a glass case? Use it- with new batteries- (but not Duracells.) You could always get another analogue meter to back it up, for outside jobs or dirty jobs.

It is likely that a collector would pay good money for it (they are popular) but it would perhaps be better if you could use it, see if it needs any attention, and benefit from having what is an interesting link between analogue and digital technology..? When these meters are working, apparently they are very good.

Dave

[hilitevr]

Hi Dave, why not Duracells?

[Refugee]

Originally Posted by hilitevr

Hi Dave, why not Duracells?

They leak and rot the inside of your meter.

[Radio Wrangler]

Type 21-S ? That's a new AVO variant on me. The case seems to be the same as the EA113, but I wonder if the 21-S is a simpler, passive meter without the amplifiers of the EA113?

Yes, it's interesting. Yes, it's worth keeping. But I'd rather see these things being used.

The almost identical looking EA113 seems to fetch crazily high prices on auction sites. It's believed to be because AVO list these as necessary to performing calibration on their later valve testers, and the valve testers are cult items amongst guitarists and hifi extremists. These factors elevate prices. I don't think the 21-S will have the same price hype factor as the EA113.

So, you've got a nice unit, with all the paperwork and things. Worth keeping together

David

[Sinewave]

21-S, wonder if it's a variant renamed of the EA113. Agreed the price of these tend to get high, luckily I have a secret stash of these meters.

[Phil G4SPZ]

What a fascinating find!

My knowledge of Swedish is nil, but it’s possible to deduce from the instruction plate that this is a passive meter with 20,000 OPV sensitivity and uses 15 volt and 1.5 volt batteries for the resistance ranges only. Hence it seems to be virtually the same as an Avo Model 9, mark V or later, in an Avo EA113 case.

[AndyGilham]

The EA113 was the Uk market version of this instrument. The original design was the Avometer models 14, 15, 16 and 20. These actually came from demand overseas, and so were designed for the foreign market. The EA113 came along a little later.
I have never heard of a model 21S but yes it seems to be a Swedish Special.
The collection I have at Megger (formerly Avo) for our museum includes 2 Ea113, but none of the others models.
What a fantastic find..... Keep it in good condition!

Andy

[Pamphonica]

Surely this is most likely a Swedish export version of the model 20, not the electronic EA113.

[pmmunro]

A range of four Avometers, intended for export sales, was released in August 1967. These were Models 14, 15, 16 and 20. All of them shared the case style of the EA113 and were passive instruments with a sensitivity of 20,000 ohms per volt. The ranges provided are shown in the attachment. Introduction on the home market was not intended to be immediate, and as far as I am aware, never happened. They certainly reached Canada and Australia and manuals were printed in English, French and German.

The Model 14 was the basic version, without alternating current ranges and an accuracy of +/- 2% of fsd (DC) and 2,25% fsd (AC). The Model 15 had an accuracy of +/- 1.5% of fsd on DC and 2.25% of fsd on AC. Models 16 & 20 were 1% of fsd on DC and 1.5% of fsd on AC. The good accuracy was attributed to the use of metal film resistors. In common with the recently developed Model 8 Mk III, these meters had thermistor temperature compensation.

They're rather nice meters, but the highest current range is only 3A.

The Model 21 replaced the Model 20 within a year or two and measured current up to 6A and the highest resistance range, using an internal 15V battery, was extended to 10Mohms.

I don't know the significance of the 'S' suffix on the Swedish Model 21. It may just indicate that it was for export to Sweden, which seems most likely as it doesn't look to be screened as a Model 8S, for example, would be.

PMM