AVO Multimeter survey

[Sinewave]

More serial numbers to add to the survey.

• Model 40 Mk 1 with PF sockets. Serial from movement scale - No. 6956-B-552
• Model 47A. Serial from movement scale - No. 13271-1243
• Model 48A. Serial from movement scale - No. 20710-945
• High Resistance Model HRM. Serial from movement scale - No. 1497-B-150
• High Resistance Model HRM. Serial from movement scale - No. 1507-150

The above Model 40 Mk 1, No. 6956-B-552 is in a 48A wooden box set. I'm not sure at this stage whether or not this is the industrial set with the Model 40, or if there were a 48A in there at some point in the past.

[The Philpott]

Until today i had treated the Model 9/II was broadly equivalent to the Model 8/III apart from: 100/30 scale, decibels scale deleted and mirror moved, ohms scale moved, LR extension range absent, and international hieroglyphics used, and other little details like a CuO rectifier instead of Germanium.

Then i noticed the AC 10mA range that i was using on the 9/II was absent on the 8/III, but the latter has an AC 2.5A range..(NO corresponding 3A range appears on the 9/II)

The military test set of this period has an AC 5A range, but no 10mA range.

(The 10mA range then appears on the later 8/IV and 9/IV- and the 2.5A range disappears)

The common thread appears to be that the number of AC Current ranges in this period was deemed to be four only!

Dave

[The Philpott]

Post No. 2181:

If there's a Model 48A instruction plate in the box that has not been disturbed then i guess you're looking at a 48A set with a newer 40 meter..

The Test Set No.1 box and the 48A box that i have are different in size, so in the absence of an instruction plate screwed onto your lid it still might be possible to establish under which nomenclature your set started life.

Dave

[Sinewave]

There is a 48A instruction plate inside the lid, though the box doesn't have the brass plate outside of the box by the latch, unlike my other 48A set which does have an actual 48A unit.

I wasn't aware of a Test Set No. 1 in a wooden box though, I only know of that set comprising of the Model 8, but no accessories apart from the leads and probes.

[Pamphonica]

Newbury Rally yesterday yielded a nice find - a late Avo8 Mk7 for a tenner.
It looked absolutely awful, in a battered and stained leather case and covered in grime, poor thing. Odd for such a recent version.
But some tlc with carefully applied foaming cleaner, and some calibration checks showed it was still right on the button and is now back to mint condition.
Avo8 Mk7 Serial no 6110-663/030303/1894.
Does anyone have any idea on the date?
I'm pretty sure it was a late model as it has the square red AVO logo instead of the earlier round conventional logo.
This link shows the very last AVO8 being calibrated and it has the square logo.
https://journals.sagepub.com/doi/pdf...29401004300302
Pictures attached of my two Avo8 Mk7s
The seller also had an 8 Mk6 and an 8 Mk5 available at the same price but I decided I must not be greedy!
This one may well replace an 8 Mk6 on one of my benches, and earn its keep properly.
- Jeremy

[Sinewave]

Hi Jeremy, that's a cracking find for the price. I've had a similar date issue with some of my 8 Mk 7's and I'm still not sure of the date of some of mine.

With the red Avo logo, yours is one of the later ones. Does it have the safety category rating on it too?

[Pamphonica]

Yes, safety category rating label between the terminals. The only odd bit is that the 4mm socket holes have been very neatly filled with solder (or something metallic) so are non-functional. You have to use spade terminal leads, which I would have thought are if anything more lethal! And thinking of it, why metallic fill, which you would have thought could be contacted. Should have been plastic. Unless of course someone managed to snap off two plugs in it, in which case I might try drilling and tapping.
I suppose I could always replace them with terminals from a scrap mk 5/6 if I find one.
Interesting...

[Radio Surfer]

Hello,

One more to add:

Model 8, mk III, Serial number 67689.1067.

Regards,

Richard

[Andrewausfa]

And another to add to the thread of AVO

Model 8 Mk III s/n 66483-967

Which makes it the 1206th after Richards October 1967 Mark III above and gives some indication of monthly production.

Andrew

[Superscope]

Thanks to everybody still contributing Numbers.

Ref #2180

Precision Avometers have been periodically reported on this Thread
over the years, and I do have them logged.
There are 9 of them in the Survey at present including Mk 1's and 2's.

It has always been my intention to include these in the Survey Document,
and they are currently just patiently waiting to be included.



Regarding Pf Sockets for Model 7's and 40's, yes, I think this is of interest.

I have been logging this Data myself for some time now, mostly by looking at Photo's
when they are available, but this information was rarely given in this Thread as it
was never previously asked for.

It has been my intention to publish this Data when I get a decent amount of entries to make it worthwhile.


So we need Data regarding whether or not a Model 7 or 40 has PF Sockets.
Also if they have a Bakelite or Metal Case,
and what Colour the Case is painted? and Paint type "Crincle or Hammered finish"


Maybe Forum Members can re-visit their Model 7's and 40's and provide the extra Data.



Regards

Ian

[Keith956]

Model 8 alas I can't read the serial number as the label is well worn. Otherwise in absolutely mint condition - sold by a lady on ebay who said it was her father's.

[AndyGilham]

A new ebay purchase
Avometer Model D (10S/10610) - Serial Number 19110-345 (March 1945)

Looks to have a missing Terminal Knob, so i will 3D print a replacement. Other than that, it looks in good condition. I will upload some photographs once its delivered.

Regards
Andy

[Sinewave]

Crikey, I did wonder who that was!

[Leon Crampin]

Model 7 Mk 1 with no PF sockets - Ser. 71145 - 24432. Black bakelite case, bakelite battery cover with "prods" holder.

Model 7 Mk II fitted with PF sockets - Ser. 2883 - A - 167 - M. Metal case and flat metal battery cover, grey "hammerite" finish, no earthing terminal.

Leon.

[AndyGilham]

Originally Posted by Sinewave

Crikey, I did wonder who that was!

Was that you i was in a bidding war with...... i do apologise!

I guess I have the advantage of not using my money, since i claim all purchases back from Megger.......since its for the musuem.

Andy

[Sinewave]

Originally Posted by AndyGilham

Was that you i was in a bidding war with...... i do apologise!

I guess I have the advantage of not using my money, since i claim all purchases back from Megger.......since its for the musuem.

Andy

Nope, wasn't me. I have 8 Model D's already, so shouldn't add any more.

[Pamphonica]

Two (small) additions, bought from the B&B at RWB yesterday. I couldn't resist them!

DC Avominor s/n 17754-74 (1944?)
Universal Avominor 112574-451 (1951?)

Also entered on the online Google database.

-Jeremy

[The Philpott]

..Saw the Model D referred to..wasn't me either!

Jeremy, i was reminded that the Universal Avominor requires concentration the other day when i discarded some feeble AA cells- only to discover later that i had set it to AC volts..
The difference is sufficiently small that you don't immediately realise that you've done something wrong! (But it's probably better than applying AC on the DC setting..?)

Dave

[micheal]

Hi Jeremy should your DC Avominor be July 1934 ? it has a very low serial number.

Mike

[Pamphonica]

Yes, probably 1934. Much more likely.
Jeremy