AVO Multimeter survey

[SPCh]

Failing further consultation with my learned friend, it is almost certainly a "Model 5":
the 36 Range Avometer introduced in June 1934.

You need to be aware of the special AVO arithmetic, here.
You have listed the switch ranges - sixteen current and voltage, four resistance.
The DIV2 button is inappropriate for the resistance ranges, but works with all the others,
so (16 x 2) + 4 = 36.

The "34 Ranges" alluded to on the instruction panel may be due to a swapped case (it often happens), but could just be AVO using up old stock - they often did in this era, particulartly in the transition from one model to the next. (I concede that June 1934 to December 1937 is quite a leap, so it may well be a swapped case).

Unless we establish anything to the contrary, yours is the FIRST "Model 5" in the survey !

I'm afraid I don't know who Ron was - PMM might, and possibly even his brand of soap !

(That's a sort of private joke: due to the specific mix of varnish, cotton, copper & constantan .... , every AVO Model and Mark has a unique characteristic smell; it even varies throughout the product's lifetime, so there are dating clues there as well !
I haven't reached the stage where I can identify Model, Mark, and production date by smell alone; PMM denies that HE has, but I''m not convinced !)

Anyway, congratulations on your acquisition, and thanks for my first Model "5".

[Phil G4SPZ]

Originally Posted by SPCh

...it is almost certainly a "Model 5": the 36 Range Avometer introduced in June 1934... unless we establish anything to the contrary, yours is the FIRST "Model 5" in the survey! I'm afraid I don't know who Ron was - PMM might, and possibly even his brand of soap... anyway, congratulations on your acquisition, and thanks for my first Model "5".

Wow... I'm honoured, your honour. As a newcomer to the sub-hobby of vintage AVO collecting, the least I can do is to post a couple of pictures of said rare beast. Apologies for mis-naming 'Roy' or 'Ray', by the way, who PMM might indeed know of (although the assembler would be at least 90 now I guess).

I have some questions on restoration, but feel they would be best dealt with in a PM to PMM. Again, learned gentlemen, thank you for all your advice.

Phil

[Phil G4SPZ]

I've just received my latest AVO, an ex-military Model 8 Mk III, s/n 84768.968.

Phil

[coil1234]

Hello All,
Latest acquisition; Test Set No1 6625-99-105-7050 (is this the NATO Stock No?)
Ser No 4050

Regards Mike A

[Phil G4SPZ]

Three more to add to my collection and to your survey:

Model D (Air Ministry variant of Model 40) s/n 342-D-9/1951
Admiralty Pattern 47A (variant of Model 40) s/n not visible
Model 7 Mk II (courtesy of Mike Fulton, for spares) s/n 72009-A-857

Regards,

[PL259RDB]

I'm new at this, but it is a interesting hearing all about the different models, I just purchased a mod 8X Panclimatic. It had a dead meter. What I found was that the upper hairspring was detached from the Collete. By being real careful I resoldered it to the Collette now is working OK. (I also do clock and watch repair) The number on this unit on the scale plate is: 158228-C-463 I have a friend that will bring his AVO over and I'll get that S/N too. PL259

[samthelemming]

A few more to add to the list:-, wasn't sure about the minors but thought I'd put them in anyway


AVO model 8, s/n 139 1269
AVO minor, no.U. 61947 1243
" " no.U. 92323 746

Sam

[Ben Puylaert]

Dear All,

Some interresting information for the Avometer survey.
One meter:
- two knobs
- Model 8X MKIII
- No 01630491
- Bakelite box
- 4 connectors
- shape of a Avometer
BUT no "Avometer" name on the front panel.

Under the desk of the Indian technician with whom I co-operate I traced a multimeter, with above mentioned characteristics.
However on the expected position of the name "Avometer" the name "Motwane" could be traced.
It seems that for the Indian subcontinent there is/was a licensee holder for Avometers.
The scale of the traced multimeter clearly indicates "Made in India".
At the backpanel the company name "Motwane", as registered in Bombay (nowadays Mumbai).
A check at the internet does not reveal much information.
So, is it a pure clone?

Regards,

Ben

[SPCh]

Hi, Ben,

Sorry for the delay, I've been out of circulation for a couple of weeks.

I have to admit that this is a new one on me. There WERE manufacturing licences elsewhere in the world, but I wasn't aware of one in India. Also, whilst I can imagine pirate copies here and there, a pirate clone seems improbable - AVO was always very jealous of its reputation, and would almost certainly have jumped on any illegal copies.

How "AVO-like is it (a few pictures would help) ?

You said it was the correct size; does it have the standard "orange-peel" texture on the front panel; is the kidney-window "right"; are the knobs and terminals recognisably AVO ?

I'll dig around for anything I can find; I'm sure my "learned friend" will do the same.

Thanks for the challenge.

[Brased]

Another AVO 8 has turned up for the Amberley workshop, serial no. 64467-C-857.

It's a bit tatty but otherwise in good condition except that the ohms ranges won't zero, so some investigation is called for.

Edward

[David Simpson]

Another two AVO 8 Mk2's for your survey :- No 141003-c-562,& no 626(stamped on front casing, no number on movement faceplate). Regards, David

[Avondale]

Hello from New Zealand.
I have a universal Avometer with no apparent model number on the case.On the dial it has Type HRM and No 507-150.On reading some previous threads I gather it was manufactured in Jan 1950.This meter was given to me when I started my radio apprentiship in NZ in 1960 and retired it around 1970.It as been in a cupboard since then.I have just pulled it out and put new batteries in it and it appears to be working fine.It has a bakerlite face and a grey mottled metal case.Is this a common or a less common model.
Regards Doug.

[pmmunro]

The Avometer HRM was effectively a forerunner of the Model 8, but without alternating current ranges. It was produced from c. 1947 until c. 1951, when the Model 8 was introduced.

There are two principal varients, both rare, which I guess, (I would like evidence but so far have found none), is because it was directed towards the export market or government contracts. At this time too, materials may have been scarce, limiting production.

Yours is an even rarer panclimatic version with the outer metal case. The inner scale arc for resistance was originally written in red and this has often faded badly. How is the marking on yours?

You will probably find more information which I have posted here in provious threads and I can provide more information - if life ever slows down to less than a blurr.

PMM.

[Avondale]

Hello Peter
I have attached two photos to help with identification.As you can see from the photos the scale is still in pretty good condition,allthough fading has started to occur.Was this made for the export market?
Regards Doug.

[Mark the Mender]

Oki doki my two avos
Model 12 s/n 2215-467
Model 8 mk 6 1078m 931940

cheers Mark

[Stockden]

I nipped out to the "workshop" to check the serial number on my Model 8 Mk6 and cant find one anywhere on the scale plate. There is, however, a paper label stuck on the side which says "TS1Mk4" (Test Set Multi Range No1 Mk4 presumably) and "1089 M931940". Based on other posts that latter number is the serial but why is it on a label and not on the scale plate?

[SPCh]

In a word, economy.
Traditionally the numbers were hand written on the scale plate prior to calibration;
to save money they were pre-printed in pairs and attached (one inside the battery box, one on the side of the case) - I suspect -on passing inspection.

[Mike-repairman]

Just checked for your survey...

AVO 8, 52142 8V/1/75 (on label inside battery box)

AVO 8, 126132-C-861 (on meter scale)

[calum]

Just picked up a military Model 8. The numbers are:

engraved near the top: 6625-99-943-1532

Bottom of scale: "Model 8 No 66044"

we assume the first is a NATO stock number or similar.

Does the survey tell you anything interesting about these, please?

thanks much indeed.

[SPCh]

Calum,
Not sure what you mean by a "military Model 8";
The NATO Stock number makes it sound like a TS-1 (which IS a Model 8 variant)
but where exactly is the "66044" ? and does it actially say "Model 8" ?.


Mike,
Your beastie soundds like a REAL marriage of inconvenience.
We often see Model 8s with the wrong case (e.g. Mk III back on a Mk II body),
but a Model 8 movement from 1961 (so a Mk II), would simply not fit a Mark V body,
and would be electrically incompatible with it.
It can't be a body/case marriage either.

The MK V was a total redesign, with a completely different body- and case- molding,
and a new-style centre-pole movement.
(The curvature of the scale did not even match that of the kidney window (shock horror !))

Sounds fascinating.

If you could open it up (in a clean-room !) and provide a few pictures
I'd like to know how it's been done.

A first indication would be "does it work at all ?" and "is it accurate ?"