AVO Multimeter survey

[Superscope]

Thanks for that Richard,

Who would have thought, Avo Minors were being Air-dropped!


The Serial Number is a problem though.
Is there any way to double check it's accuracy?

69982 should push it to late 1942, unless of course, there is
yet another Serial Number Range running.


The Avo Minors were notorious for multiple Number Ranges running in parellel.
There were at least Two running in 1941.

A prefix U. Range hovering around 40 Thousand mark, and a
no prefix Range hovering around 64 Thousand.



Ian

[Barnmead]

Hi Ian
I have contacted the owner who is currently away from home. I hope to get confirmation in a day or two. In the meantime he sent a picture of the transmitting site of a Dutch secret agent in the cellar under a hospiral in Amsterdam. You can see an AVO minor on the top shelf.

[Superscope]

Amazing, not just the Photo, which is fabulous, but the fact that the Story around it still survives.

What I find surprising, is just how small the Equipment is for the time in question.
The Avominor is not exactly big, but it looks big next to the other stuff in the
Photo.

I wonder what the 3rd Reich thought when they got their Hands on their first
captured Avominor?


Ian

[The Philpott]

Fantastic. I'm not sure what rival Germany had for the Avominor, but broadly speaking the equivalent of the Avo was the Hartmann & Braun Multavi. I can testify that they are the size of an engineering brick and seemed even heavier. (No handle, but the leather case had a handle as i recall.) Quite a cumbersome lump.

The fact that the subject Avominor survives is quite amazing.

Dave

[Superscope]

This might be a bit off Topic, but is useful infomation none the less.

Comments can be added to a Photo like the one posted by Richard in the pictures Metadata.

So for example, I have added the Words of Richard's post to the Photo, so
when I look at it again in many years time, I can be reminded about what
it's all about instead of wondering why I kept a copy.

In Windows, Right Mouse Click the File (can also be done if the Photo is open), select Properties, and look down the list to Comments.
Click and add what you want.

Any comments remain with the File if it is sent elsewhere or otherwise copied.

Similar process in Linux.

I now always edit Photos in this way unless somebody has already added
information.




Ian

[pmmunro]

Originally Posted by Superscope

Amazing, not just the Photo, which is fabulous, but the fact that the Story around it still survives.

What I find surprising, is just how small the Equipment is for the time in question.
The Avominor is not exactly big, but it looks big next to the other stuff in the
Photo.

I wonder what the 3rd Reich thought when they got their Hands on their first
captured Avominor?


Ian

This story doesn't tell us what model of Avometer fell into the hands of the Nazi regime but does confirm that one did. It would most likely have been a Minor or Universal Minor I would guess.

https://www.bbc.co.uk/history/ww2peo...a2665244.shtml

"Before leaving his last base at Hope Cove in South Devon, to take part on his mission, Jack (Nissenthall) prepared his blue RAF small pack with his most precious possession, a small avometer given to him by his late father for his Barmitzvah". Mr. Nissenthall senior was clearly a generous and supportive father whatever model it was!

PMM

[AndyGilham]

Ian, I remember using metadata on photos way back, it’s a good way to ensure all info is retained. However, these days I index in an excel spreadsheet with a hyperlink to the document. That way I can columns of info, date, names...etc.

[Superscope]

Hi Andy,

Welcome back.
Haven't seen you on the Survey Thread for ages.

Yes, Metadata is nothing new, but it does have the advantage, that
the information stays embedded in the File and so can't get lost
or separated, at least accidently.
Of course, any File can have its Metadata edited, Pdf's and Video Files
included, so it is very useful.

Although, there is always a place for a Spreadsheet for the wider picture! (No pun intended ).

For the Survey, I currently run two different Excel spreadsheets for testing,
and an Access Database where the Final Data is stored and Reports are run.



Ian

[Barnmead]

Another step sided avominor number for the list:73663 943 in poor condition but movement seems OK

[AndyGilham]

Ian,
I pop up now and again and have my say or show my wares!
I have gathered so much data related to Avo (Evershed & Vignoles) I rarely get time to sort it. People give handed me info and photos, documents, drawings...etc endless. Just writing up notes and history has run into a 75,000 word document.

Richard,
Thank for the serial number, I have added to the list of 82 Avominor serial numbers and now 128 Universal Avominor serial numbers + many more of the variants.

[Superscope]

So, carrying on with the estimated Production Numbers, the following
takes it up to and including 1970:

The Numbers include all Meters made that year.

Numbers dropped significantly after WWII, which I guess would be expected,
but seems to have taken Two or Three years to set in.
I'm guessing there was a hugh amount of ex Military Surplus in the immediate
years after WWII, which must have impacted on Production of New Equipment.

Interesting Dip in 1949, so maybe there were Specials being made in the lead
up to the Cold War we don't know about, or other meters we have no Data on.

So here goes:

1946 = 48373
1947 = 26816
1948 = 11690
1949 = 9305
1950 = 12846
1951 = 23053
1952 = 25549
1953 = 23330
1954 = 25568
1955 = 25809
1956 = 37567
1957 = 39264
1958 = 35967
1959 = 37139
1960 = 37524
1961 = 41872
1962 = 48080
1963 = 55312
1964 = 47464
1965 = 52511
1966 = 52140
1967 = 53292
1968 = 46945
1969 = 46151
1970 = 48500

Estimates from the Mid 60's onwards will become less accurate as certain Meter Types
are not currently included in the Data. (Precision Avometer, Model 12, 16 ect)

Ian

[Superscope]

The estimated Yearly Running Totals as follows:


1923 = 1643
1924 = 3286
1925 = 4929
1926 = 6572
1927 = 8365
1928 = 9165
1929 = 10015
1930 = 10915
1931 = 11865
1932 = 13300
1933 = 19786
1934 = 51267
1935 = 58652
1936 = 66936
1937 = 79401
1938 = 92422
1939 = 104326
1940 = 119645
1941 = 139584
1942 = 178656
1943 = 215546
1944 = 252962
1945 = 289459
1946 = 337832
1947 = 364648
1948 = 376339
1949 = 385643
1950 = 398489
1951 = 421542
1952 = 447091
1953 = 470421
1954 = 495990
1955 = 521799
1956 = 559366
1957 = 598630
1958 = 634597
1959 = 671735
1960 = 709259
1961 = 751131
1962 = 799212
1963 = 854523
1964 = 901987
1965 = 954498
1966 = 1006638
1967 = 1059930
1968 = 1106875
1969 = 1153026
1970 = 1167526

I didn't get any feedback regarding the MultiMinor, so I have assumed the
Launch Year to be 1956 and the Final production year as 1970.
The total number of Multiminor's produced based on the Numbers we have,
has been averaged across the Build Years with a slight reduction at the
begining and end periods as one might expect to have happened.

The 1 Millionth Meter conveniently ends up in 1966, so hopefully, these are
reasonable good estimates.




Ian

[Superscope]

I know the Military use Kit which is often old (but well maintained),
but I was still surprised to find this Model 48A, still in it's original box
with all the accessories which was last Calibrated in March 1994 by
Devonport Management Ltd.
This was not a Mint condition Meter, it has certainly been used,
but well looked after.

A full 50 years of service from this 48A, and quite possibly it has
been at the Devonport Navel Dockyard all it's life. Who knows!
Meter is Dated to October 1944.

So it looks like the Tax payer at least got value for money for a
change on this piece of Navel Equipment.



Ian

[The Philpott]

Rather interesting. Cold war precautions/paranoia did lead to basic and/or analogue examples of equipment being retained for a surprising length of time (incidentally even moreso with the Soviets than the Brits)

Dave

[pmmunro]

I've also seen Admiralty AVO equipment with surprisngly recent calibration labels.

Could it be that equipment remains "on the books" as long as some larger unit, such as a ship, lists it as part of ots requirements?

PMM

[The Philpott]

I can quite believe that. It would be interesting to hear from an insider in this respect.
Dave

[Superscope]

I think that's highly likely.

I can't imagine it would have been used much during the later years.

However, that said, when you need to measure Current and Voltage
at very high levels, which might happen at a Dockyard with High power
generators and the like, then I can't think of anything much more suitable
than an old Model 48A Set.

At least all the necessary Shunts & Multipliers are all in one place.

This one not suprisingly, still seems to be in full working order, although
I haven't got round to checking it's Calibration yet.

Only bad points are a missing Dataplate in the Lid and the
colonies of Insects that had made Home inside the Box.

Obviously not been Stored particularly well after leaving Devonport.
Or maybe it was them, and they left it an old out building or something
until rediscovery.



Ian

[AndyGilham]

Good morning all.
I have just received a new meter, the Avo-International Rectifier Multiminor.
I know this was discussed briefly back in post 2354 when 'Michael' detailed one of these instrument. His serial number was 179-763, whereas my one is 223-763, which maybe implies a lot of the these were made in a short period of time. Maybe a one-off batch for IR.

The instrument was as shown, a little grubby and with no extras.

Interestingly I received the wrong instrument in the post. Opening the box in excitement and being presented with a standard Multiminor. I contacted the seller and he apologised and sent the IR meter through... and told me to keep the Multiminor! So a free instrument in that error!

Andy

[Superscope]

Thanks Andy,

That was a result.
Two Meters for the price of one and a Rare one at that.

Yes, it would certainly appear that the Zenor Diode Test Meter
was indeed a One Off production Run.

The Meters we currently know about, are all July 1963.


Does your Standard Multiminor have any Number, or more importantly
a Date indication of any kind?

Strangely enough, it's the Multiminor that is giving the most trouble
in the Survey to Date.

Very few Numbers reported, and only Two Dates which I believe are incorrect.

I believe the Multiminor was released in 1956, but I don't know where I
got that information from, so it is currently only an estimate, unless
somebody knows more.
Also, I'm not sure when the 70 Series Meters started production, so the
Multiminor end period is also not currently known for sure.

I haven't had any Multiminor Feedback from anybody to Date, so this Meter
is a big unknown in plane sight.



Ian

[AndyGilham]

Ian
The serial number for Multiminor are elusive, and none of meters I have include it.
However, I just had a look in the archives and found a list of official variants.

Multiminor Model 1 (Standard Accuracy)
Multiminor Model 1A (High Accuracy)
Multiminor Model 2 (Standard Accuracy / Panclimatic)
Multiminor Model 2A (High Accuracy / Panclimatic)
Multiminor Model 4
Multiminor Model 5
Multiminor Model 5 Services
Multiminor Svenska Special
Multiminor IBM Special
Multiminor Home Office Special

So that's quite interesting! And certainly no sign of a Model 3...

Andy