AVO Multimeter survey

[Fredddy]

Starting in 1963 when I bought my first (2nd hand, fron Technical Trading in Portsmouth) AVO 7 (7647-36238), I now have a few others - half work and the others are for spares...

So:
Model 9 Mk II No. 1025-1065
Model 9SX 9616 IS-366
and a Model 8 Mk II with no number

I also have another AVO which I keep in my office (I'll send the number later)

I also have , a model TT169 in-circuit transistor tester and 2 valve testers (mark 1 - I think, in a wooden box with a metal plate saying "BOX FOR ADM VALVE TESTER") and a mark 3 Number 4268-553U. All the above, except for the Model 7, were bought on ebay from Germany.
I also have a 500V Megger Number 91238 which was donated to me by a Luxembourgish friend and an AVO Electronic meter (uses a 6SN7 and has good Watts ranges) I picked in my travels.

All this lot is going to Crete with me when I retire...

[Alpha_PA]

Hi to all from new member Alpha_PA (Alan)
I have 4 AVO Mk8s that I have just acquired via auction from BAE SYSTEMS Integrated System Technologies (my daytime employer) - These were originally Marconi Underwater Systems Ltd. equipment and (given it's age) the early Model 8 would probably have originally been at the GEC/Marconi Broad Oak Works / Brown's Lane site in Portsmouth.
AVO Model 8 S/No. 38290-C-955
AVO 8 MkV S/No. 0013020 8V JA
AVO 8 MkV S/No. LC 0527914 8V
AVO 8 Mk6 S/No. 0010404 KE (MOD8/6 12/84)

Regards
Alan

[AlanBeckett]

Steve,

Model 8 No. 103412-C-260

Date?

Alan

[SPCh]

Alan,

Second half of February 1960. I've even know two of the (five possible) girls who would have calibrated it.

SPCh

[AlanBeckett]

Steve,
It belongs to a friend of mine.
The movement may be O/C
Alan

[russell_w_b]

Just been given an ex-Air-Ministry AVO 7 Mk.I, serial number 7644-16927. Used for many years by a TV and radio dealer / repair shop in Hexham, Northumberland.

I would appreciate some information as to the date of this instrument!

[pmmunro]

Russell,

Your meter was made in June 1944. The pattern is 7 - Model 7 meter, m(m)yy - serial number, where m(m) is the month and yy is the year.

A similar system was used to allocate Model 40 serial numbers prior to the adoption of the more familiar system without the model type in the serial number and the last group of figures representing the month and year.

PMM.

[russell_w_b]

Originally Posted by pmmunro

Russell,

Your meter was made in June 1944. The pattern is 7 - Model 7 meter, m(m)yy - serial number, where m(m) is the month and yy is the year.

PMM,

Many thanks! Sadly, the balance is way-out, the meter has been stored in a damp place, the pointer sticks and there is that horrible brown pock-marking on the scale (but other than that it's fine )

Spares or a challenging fixer-upper, methinks...

[glowing antique]

Hi There
Just been through my cupboards and dug out another two meters.

UNIVERSAL AVOMETER MODEL 8X (PAN)

Case Serial No. 6625-99-943-1532

Movement No. 168602-C-564
Part No. 13574-3.A.



UNIVERSAL AVOMETER MODEL 40

Meter Movement No. 4011635-746

Hope this helps with the survey
Simon

[ve3id_Nigel]

Hi folks,

Just joined the forum, looks like a good meeting place for fellow-travellers.

I was given an AVO 8 on my 50th birthday with a note saying that it is as old as I. Growing up in the U.K. I could never afford to have one when I started using meters as a teenager, so it is very dear to me.

My s/n is 23325-C-454. I was 6 months old when it was made in April 1954! I believe this mades it a mark 1 instrument, can someone confirm?

I am looking for a 15V battery in Canada. I go to the Dayton Hamfest every year, so maybe I will have better luck there.

Can anybody tell me what DOES the 'C' in the s/n mean?

cheers,
Nigel Johnson
g4ajq/ve3id

[SPCh]

Hi, Nigel,

Welcome to the Forum. It's nice to have a first post giving information rather than asking for it - thanks for your contribution.

Yes, your meter dates from April 1954, though that was the calibration date. It was almost certainly made near the end of March. It would have been calibrated by either Linda or Jennie (Denise was off sick for two weeks at that time).

So, 56 years old, and still "going strong" - but quite young for an AVO;
there are 75 year olds still as accurate as the day they were calibrated;
in those days, they (including yours) were calibrated at ten or twelve cardinal points -
not just at full scale ! That's why they were the best !


The letter in the serial number identifies the type of movement (i.e sensitivity):
C is for the Model 8, B is for (most of) Model 40s, and A is for the Model 7.

Happy measuring.

SPCh.

[ve3id_Nigel]

Blimey! How d'ya know that? You must have been either a) there at the time, or b) have the log books, or c) they are published somewhere!

[SPCh]

Nigel,

No; not a), b) or c).

Just a lot of research, with a few lucky breaks, and a personality which could "charm fleas out of a hedgehog".

SPCh.

[Dave Moll]

I don't think that I have yet reported my acquisition at Harpenden:

model 40 ; serial no. 29769 40/1/71

[hilitevr]

Hi,

I just aquired another AVO High Resistance Meter, HRM serial number 772 349

Works fine after fixing a few minor problems.

Regards
Trevor

[calum]

Just picked up a nice 8 MK.III

5433.1164

cheers, calum.

[Muskrat]

I have been given two Avo meters, unfortunately, no leads or cases. They both seem to be in good condition, except for old batteries stuck in the battery box. I intend cleaning them up and using the Model 8 on the bench.

Model 7
Serial 7942-8335

Model 8X (PANCLIMATIC)
Serial 61638-C-657

I am resident in South Africa, have no idea as to the history of these two instruments.

[pmmunro]

Muskrat,

I don't know how closely you've been following this forum thread but you may not be familiar with the serial number sequence of the Model 7. Your meter dates from September 1942.

PMM.

[Muskrat]

That's amazing! I had a vague idea about the serial numbers but didn't realise that the 7 was even older than I am! Dare I say it works better too!!!

Just goes to show that when things were built properly, they could be realistically expected to last a lifetime. Where has craftsmanship gone?

Other test gear I have bought (of the mass-produced, without a care in the world variety) have not lived for long, even though I treat all my test gear with a great deal of respect.

Thanks for the info.

[olly 476]

I was recently given,the generosity of some people never ceases to amaze me,an Avo.
A Model 7 (assume Mk 1) No.xxxx.A-248