AVO Multimeter survey

[SPCh]

Note from the Moderators, 26/02/11:Please see this thread:-https://www.vintage-radio.net/forum/...ad.php?t=66167

Also see post #638 in the current thread:-
https://www.vintage-radio.net/forum/...&postcount=638

See also post 1530 and 1533 with regard to an on-line database being created for these meters:-
https://www.vintage-radio.net/forum/...postcount=1530


I am trying to compile an unofficial history of the AVO multimeter (unofficial beacause there is no official interest in the project).

I doubt if there are many Forum members without at least one AVO, so there should be enough material for me 'out there'/'in here'.

If each of you could let me know the Model & Serial number of any AVOs in your possession, I should be able to derive quite a story from the information.

I'm sure that many of (y)our multimeters were, er, liberated , so in order that they and their owners remain untraceable 8) I suggest that all but the first digit of the first number group be replaced by Xs.

Thus my 8 mk2 54112-C-1256 would become a Persil-white 8 mk2 5XXXX-C-1256. (The letter and the numbers in the last group are important ).

If you post your replies in this thread everyone will be able to see how the survey is going . If you're bashful you can use the PM channel.

It doesn't matter which model you have - the older the better for my purposes - if it's got a serial number on the scale plate I'd like to know about it.

I'll post any conclusions so all who contributed can say " I was there on St. Crispin's Day " .

Thanking you, as they say, in anticipation.

Cheers

[Sam]

I will check-out the serial numbers of my AVOs when I am home from Uni (an 8 MkIV, and a 7 MkX I think). There are a few hanging about at the back of the electroncs lab at Uni, but I'm not sure if they would like me taking them off the shelf!

Sam

Greetings,

Model 8 Mk 3 Ser. 77157 368

Much appreciated, mint condition, original owner - sadly not much used now except as a peak indicator for alignment. 5 Lithium batteries work brilliantly to power the high ohms range, and fit between the clips taped as a stack, fitted with a spacer.

Leon.

[Mike Phelan]

Hi spch
Model 8 Panclimatic 75370 C 658
Excellent condition - metal outer case finished in a sort of hammered bronze - owned for 30+ years - good condition. Originally from surplus shop in Warrington.

[mickjjo]

Hi, I have a Model 7 mk2 No 1108-A-1164
The meter is near mint and has all the original leads and probes and AVO instruction manual. I paid £10 at a boot sale about 8 years ago. . It doesn't often get used, I tend to prefer the convenience of a modern cheap digital meter, .

Regards, Mick.

[Darren-UK]

I've got an 8 Mk2 but it's number is partly worn. It's defo 95151 - C - and the last digits appear to be 1159.

My other is a 7 ( no Mk ) number 28908 - A - 1151.

[Steve]

My workshop 8 (the other is buried in a box somewhere) is :

Avo 8 Mk.V - 2 0031914 AC

Talking of AVOs, can anyone recommend a cheap source of replacement leads & probes?

[Gordon]

I have a Model 8, Ser. No. 105991-C-460 which I bought last year for £30. It came with a hand-written calibration certificate.

Gordon.

[Ken]

Hi SPCh

I have an AVO 8 Mk V. Not sure if it was liberated but I know it was going to thrown out. The serial number is 0XXXX 8V/1/74. It looks a bit different from the others in this thread. Could the last part (1/74) be its date of manufacture?

Regards,

Ken.

[SPCh]

Yes, Ken. I suspect the old numbering scheme stopped in the 60s, when soulless mass production set in. The early models had personality, with someone who cared cossetting them through final test & calibration.

Keep 'em coming guys & gals. Use XXX anyway. That way you unpoint your fingers for those ...

Steve

Hi SPCh,

I actually never owned an AVO. However, I have just seen one in a secondhand shop lost among some old furniture, clothing, paintings, etc. I was considering buying it. It is missing its battery lid, but other than that looks OK.

I was going to ask for opinions should I buy it. If I do buy it, I am tempted, then I will post the serial number and details for you. However, I do not know whether you are interested in AVOs from Australia in the first place.

Regards
Andrew

My Model 8, - 136361-C-362
purchased from Telecom (Aust) auction for $50 some years back and then scrounged all the accessories, instruction book & 10 KV DC Multiplier and lead through work

Harv

[Paul_RK]

The resident Model 8 is 59054-C-457.

There's also a Thorn period Model 7, 88000 7/11/75.

Paul

[pmmunro]

Avometers Serial Numbers As I believe them to be:

This is based on much research and a little speculation but appears to conform well to the other known facts - examples are taken from actual instruments. Model numbers in brackets were not used by Avo or the The Automatic Coil Winder and Electrical Equipment Company (ACWEECO) as they were before about 1953. If you can add to or correct to this list, please let me know.

'The Avometer' (Model 1) 1923 -1927 six figures, e.g. 135923

DC Avometer, 13 range (Model 2) 1927 - 1936 four figures e.g. 1562, 3588

Universal Avometer, 20 range 1932 - 1933 (Model 3)
M(M)Y XXX, where M is the month and Y the year within the decade. e.g. 13-919 January 1933, ser. no. 919

Universal Avometer, 34 range Dec. 1933 to June 1934 (Model 4) - As for 20 range Universal (speculative no example available).

Universal Avometer, 36 range (Model 5) 1934 - 1939
As for 20 range Universal

Later DC Avometer, 22 range (Model 6) c 1935 to 1939
Unknown, believed to be as for 13 range DC Avometer.

Early Model 7 Aug 1936 to 1947
7M(M)Y XXXX e.g. 729-2613, February 1939, ser. no. 2613

Early Air Minstry Spec 'D' 10A/10610 as for 20 range,
e.g. 39-8232, March 1939, ser. no. 8232

Model 40, original type, 1939 XXXX M(M)YY e.g. 2438-640
Serial no. 2438, June 1940

Later, early Model 40, as for Model 7, e.g. 404941-543, ser. no. 4941, May 1943

Admiralty Pattern 47A, 48A, XXXX-M(M)YY
e.g. 9299-842R ser. no. 9299, August 1942 - suffix possibly variant or production plant?


Later Air Ministry Spec. 'D' 10S/10610,
DXXXX-M(M)YY, e.g. D1631-241, ser. no. 1631, Feb. 1941

All models from c. 1947 to 1973, XXXXX-V-M(M)YY,
e.g. 656-B-248, Model 40, serial no. 656, variant B, Feb. 1948 (Variant B of the Model 40 does not have reverse AC overload protection diode across movement and has modified swamp coil).
Air Ministry Model 'E' is an exception, e.g. E349 1954
Serial no. 349, made 1954.

After 1973 to date
Serial No./Type/M(M)YY, e.g. 92936 8V/7/73

Model 8 Mark V, serial no. 92936 July 1973
with variants which even Avo can't explain.

As you will gather, I don't have a 34 range Universal or a 22 range DC Avometer, but I am interested in acquiring them.

My Contribution:
Universal AVO minor 68160-744
Avo Minor 6xxxx-742
Heavy Duty AVO 7xxx-957A
AVO7 7xxx-26082
AVO8 2xxxx-C-1154

[Richard]

Hi SPCh

2 AVOs here,

AVO 8 Mk V, serial no. 96246 8V/2/76

and a spare, stuck in the shed.

AVO 8 Mk III, serial no. 144882.C.862

Richard

[fezman]

Here's mine: AVO Model 8 Mk IV, serial number 5XXXX 84-9-71

[mickjjo]

I've just unearthed an AVO Multiminor MK 4 ,
No 68829 Date (written inside) 29-4-69 ?

Is there any truth in the rumour that the government is thinking of imposing a possession tax on Avometers? Apparently they are already collecting serial numbers... .

Regards, Mick.

[adrian]

3 Avo's out here in Mexico

Model 8 Mk.II (with bad shunt) #132275-C-1261
Model 8 #2715-C-152
Model 7 #29062-C-1151

Personally, I find a cheap DMM to be faster but the AVO's (and all the Marconi VTVM's I have) have their uses.

Adrian

Hi SPCh,

I went to check out that AVO properly and then wanted to offer to buy it. Well, the lady was frantic when I lifted it off the shelf. She said you either buy it or do not touch. I poited out to her that I was interested to buy it and I wanted to check to see if all was OK as a few things were missing, like the battery compartment lid and the clip for the black lead. I also saw one of the knobs melted probably from a soldering iron. She responded that people steel things, that is why those things are missing. Then she took it from me and put it up on the to shelf behind her. She said this is antique and whether it works or not it will cost you $85.00. I thanked her politely and walked out.

If I saw it correctly it was an ex Telstra unit from Sydney and appeared to be model 9x if there is such a thing. I saw the serial number too, but I did not have a chance to take it down.

Well I just have to continue using my dust collecting 99 other test meters. I suppose the really good news is that now I can spend this money on something else I really do not need.

Regards
Andrew