AVO Multimeter survey

[Superscope]

Thanks Jeremy,

That's a nice collection of Model 2's you have.
I have made a note to correct the Serial Number.

Avo moved to Rochester Row in 1927, and I am assuming this wasn't
coincidence that the Model 2 started production the same year!

They moved to Douglas Street in 1930.

It appears that the change to Douglas Street happened around Model 2 No 3300 give or take 50.
I don't know yet exactly when Avo moved in, but I think it is safe to say any
Model 2 in the 3000's will likely be 1930.
Just need to try and work out (Guess) how many were made on average.

Your 6052 was probably one of the last Model 2's made, so maybe a 1935-1936.



Ian

[stevenkw2t]

I have an AVO multimeter and I know a bit about its history. It is the heavy duty model but I don't know when it was manufactured. I borrowed it from my father in about 2003 and never returned it. At that time I think he had owned it for a very long time. A lot of his gear dated from the 1950s to 1970s.
On the side is engraved in cursive script: "the property of C Roy Nilsson Pty Ltd 154 Castlereagh St Sydney"
C Roy Nilsson was the head of the NSW Electrical Contractors Association for a large part of the 20th century. He returned from the Great War, founded his electrical contracting business, which specialised in industrial and commercial installations, and did very well. The Sydney Morning Herald has many mentions of him and his business during the 1920s - 1950s.
Nilsson died in 1983 and his business ended with him. Presumably all the plant and equipment was sold off or was dispersed by other means. So maybe my father acquired it at around that time. One of my brothers was working as an electrician during the 1980s so I might ask him if he knows anything about it.
I've attached a few pics. I can't remember why I borrowed it - I really don't need such a heavy duty multimeter and I've only used it occasionally out of curiosity.
-Steven

[AndyGilham]

I shall check my model 1 and model 5 during the week.
Currently I am in discussion with the son of the man that worked with Donald Macadie. He joined the company in 1929 and was involved with the move to Douglas street. He was also a magpie for keeping documentation. I am some great info that is slowly being incorporated into my history of the company; which is currently 40,000 words strong.
I also now have the original 'Automatic Coil Winder and Electrical Equipment Co, signage from the Vauxhall bridge site. And I am being sent 6 cinefilm reels of the factory and sites in London and Dover.
I am looking forward to it all.

[Superscope]

Steven,

Thanks for the information and Serial Number.

Your Heavy Duty Avometer Dates from June 1950, so it is an early one.
The Heavy Duty Avometer was launched in 1948.

That looks to be in very nice condition.
Not bad considering it will be 70 this year!



Ian

[Barnmead]

I have been sent images of a model 1 serial 135988 which has label Wellington House Buckingham Gate. Hope to find out more!

My model 2 (13 range) serial 3478 horizontal magnet 3 metal adjusters Douglas St

My model 3 (20 range) serial 112-685 horizontal magnet 3 metal adjusters no back plate

My model 6 (22 range) serial 6540 vertical magnet 2 Bakelite adjusters Z one metal Douglas St

Trust this is useful.

[hilitevr]

Hi Ian

My Model 1, no instuction plate on back but also signs of glue on inside of battery cover.

It has a plate on front with an address.

Wellington House
Buckingham Gate
London SW1.

A photo of what may have been stuck on battery cover in.cluded

[AndyGilham]

Originally Posted by stevenkw2t

I have an AVO multimeter and I know a bit about its history. It is the heavy duty model but I don't know when it was manufactured. I borrowed it from my father in about 2003 and never returned it. At that time I think he had owned it for a very long time. A lot of his gear dated from the 1950s to 1970s.
On the side is engraved in cursive script: "the property of C Roy Nilsson Pty Ltd 154 Castlereagh St Sydney"
C Roy Nilsson was the head of the NSW Electrical Contractors Association for a large part of the 20th century. He returned from the Great War, founded his electrical contracting business, which specialised in industrial and commercial installations, and did very well. The Sydney Morning Herald has many mentions of him and his business during the 1920s - 1950s.
Nilsson died in 1983 and his business ended with him. Presumably all the plant and equipment was sold off or was dispersed by other means. So maybe my father acquired it at around that time. One of my brothers was working as an electrician during the 1980s so I might ask him if he knows anything about it.
I've attached a few pics. I can't remember why I borrowed it - I really don't need such a heavy duty multimeter and I've only used it occasionally out of curiosity.
-Steven

Steven
Your meter is an early commercial version of the heavy duty meter. The early ones were manufactured with aluminium front panels, but this was changed to Bakelite later on, assumingly to save costs.
The commercial version went up to 1000V, the railway (BR and GWR) version only went to 750V and 200V respectively.
I have an early aluminium GWR, but it's not in great condition, your looks fantastic.

Andy

[Superscope]

Richard, Trevor,

Thanks for the information on the Model 1.
Wellington House, Buckingham Gate, London SW1 is a new Address for me.

I was given ACWEECO's address from 1923 as "Office 9, Victoria St, London S.W.1"
Could this have been a Head office I wonder with production at Buckingham Gate?


Regarding the Magnet orientation, I was only really refering to the Model 5.
As far as I know, the Magnet was always in the same plain ( i.e. Parallel to the Scaleplate) from the Model 2 right up until the early Model 5's, then, at some point, it changed to the more familiar arrangement found on the Model 7 where the Magnet is Perpendicular (90 Degrees) to the plain of the Scaleplate.

I am trying to establish if this change happened at the same time as the Control Knob change from exposed Screw Head to Bakelit cover.

The attached Photo shows a:
May 1937 Model 5 on the left ( 90 Degree Magnet & Bakelit Controls) and a
May 1934 Model 5 on the Right. (Parallel Magnet & exposed Screw Head Controls)


Ian

[Aitor Eneko]

As far as I know 2 models for model 5
Metal screws until 1936 vertical magnet (parallel to scale)
Baquelite screws from 1936 horizontal magnet

[Phil G4SPZ]

Originally Posted by Superscope

...could anybody with a 36 Range let me know the P & R Control style...

Hi Ian,

Coping reasonably well here, thanks for asking.

My Model 5 (57-6625) has Bakelite P & R knobs. I haven't opened it up since I restored it, but I think it has the later style magnet orientation. Incidentally, I still use it quite frequently as the lowest resistance range is quite useful and readable down to 0.1 ohm.

[Aitor Eneko]

Well i did what i consider a very complete list of all the AVO models and variants, i translate it from spanish, in my version i have little bit more information of each model, but i think that the list you can find attached gives very important info. Probably with errors that i will appreciate to hear.

[AndyGilham]

That's just a slight extension to the list I put on here..... Add another 200+ variants inbetween and you will be getting close. ������

[Aitor Eneko]

i did not see that list, i made it 2 or more years ago. Where can i find your list??
did you include the biding post, PF variations and aluminium/baquelite case variations?

I know there are many variations with the resistors and other interior parts, my list is only a good way to recognise different variations of each models, it is true that there will be many sub-variations inside, but for me and my collection, these inside sub-variantions are another story i am not interested in.

[Phil G4SPZ]

For clarity, Aitor, does your list represent your own personal collection of Avometers? I see it contains several identical duplicated entries which I assume are simply additional examples of the same model.

[Aitor Eneko]

Hello, no, it is not my personal collection is just my list of variants that i use to control my collection.


I think there are not duplicated entries, they are variant for example in PF conector or not, baquelite or aluminium case..

[The Philpott]

Post No.2490 by Phil-

I have found the same on the 1,000/10,000 ohms ranges on my Model 4:

It's accurate to the thickness of the needle down to less than 2 ohms- not what i expected at all, particularly as it was very battered and tired when i got it. It performs this way until you get down to 1 ohm which it shows as 1.1 ohm. If you look inside it you get the impression of more refined and solid manufacture than slightly later meters, and oddly it doesn't smell anywhere near as strongly as the WWII era units.

Dave

[AndyGilham]

Originally Posted by Aitor Eneko

i did not see that list, i made it 2 or more years ago. Where can i find your list??
did you include the biding post, PF variations and aluminium/baquelite case variations?

I know there are many variations with the resistors and other interior parts, my list is only a good way to recognise different variations of each models, it is true that there will be many sub-variations inside, but for me and my collection, these inside sub-variantions are another story i am not interested in.

Aitor,
Well I added the list a year ago roughly and you commented on it. That’s the reason you have instruments on the list that only I would know about.
But the rest of the variant info is useful.

Andy

[Aitor Eneko]

I began my list 2 years ago, probably I include the new models you only know. But the value of the list are the variants that I think are new here. I do not remember to see a list with the models variants before.

Thanks for your list and comments that are always welcome. Perhaps you can improve that list. It is an open one, a list to work with

[Aitor Eneko]

See post

https://www.vintage-radio.net/forum/...=4343&page=101

There i said

"Thanks very much, it is correct, but many variants and sub-variants are not in that list, for example: Avo model 5 there are 2 version, with the Zero made of metal and baquelite, there are Sub-variants in Avo 7, 40, etc with or with out PF, with old style binding post or front... Only in AVO 7 10 sub-variants...

As Andy said, it is very complicated and in that list there are models that i didn´t know to exist, like model 40 braille and others... Many thanks! With that interesting info that Andy attached and my own reseach of sub variants, i will try to make a complete list."

That is the list that i presented yesterday.

[Phil G4SPZ]

Originally Posted by Aitor Eneko

Hello, no, it is not my personal collection... I think there are not duplicated entries, they are variant for example in PF conector or not, baquelite or aluminium case...

Sorry. I glanced at the list and I saw several Type D Mod 2 entries that appeared identical, that was all.