AVO Multimeter survey

[millwright2309]

Originally Posted by Superscope

Dating Multiminors has always been a bit of a problem, and has been a pain for the Survey.
Made even more difficult when it came to light recently that Avo supplied replacement
Mk 5 Movements and Scaleplates for repairs to older Mk's.

Meaning a Multiminor displaying Mk 5 on its Scaleplate is not necessarily a Mk 5 and
other features might be required to actually identify what it is.
One assumes this could also have been the case previously with other Mk's.

Now, very little is cast in Stone with Avo meters as everybody knows, but is it possible that
Universal Instrument Services supplied the Multiminor Second Hand?
The reason I ask, is that it is unlikely (but not impossible of course) the Multiminor was still
being made or supplied in 1979.
The Multiminor was replaced around 1970 by the 70 Series Meters.
It could of course also have been sitting on a Shelf for years and sold as NOS.

Your Meter as you probably know will be a Mk II from 1953.
By square Batteries, I assume you mean the Two 4.5v Cycle Batteries, or do you mean the
single 1.5v Battery?

As a general rule.

Values of course will depend on it's condition and supplied accessories.
I'm not sure what the values are for Canada, but for the Uk, If its scruffy with chips and
scratches and doesn't work at all, then it has very little value.
You would struggle to get £10 for it here in the Uk for spares.

If it is in very good cosmetic condition with a Case and leads (even with missing Prods) and
it at least shows signs of life, you might be lucky and get around £25-£30.
Although I don't often see Model 7's get that high unless they really are in good shape.

The Model 7 for some reason is not a particularly sort after Avometer and that reflects in the
price.

Some photos would help to gauge general condition.



Ian

It has the square 1.5 volt battery.

[The Philpott]

Avominor Protimeter s/n- 545-558 !

How many do we know of now....would it be 6 including the ghastly steampunked one that featured on etsy some time ago?

I'll start a separate thread with images.

Dave

[Superscope]

Originally Posted by The Philpott

Avominor Protimeter s/n- 545-558 !

How many do we know of now....would it be 6 including the ghastly steampunked one that featured on etsy some time ago?

I'll start a separate thread with images.

Dave

Yes, it is indeed the sixth one we have listed, including the butchered, sorry, Steampunked etsy one.

One assumes this one is probably towards the end of production.


Although we have Six listed, it is not clear if these all actually still survive.

Two of the numbers were provided by Andy Gillham from Avo and I'm not sure if these
were surviving Meters or just happened to appear on historical documentation.



Ian

[millwright2309]

My model 7 and a Hoyt AC/DC volt meter.

[millwright2309]

The batteries that were in my model 7, bought in August this year 40632-A-353, AC/DC seems to be working well.

[The Philpott]

Wow! I believe that sulphur fumes from the rotting rubber test leads can blacken the switch contacts inside the avo, so best kept separate! Does the AVO 7 have a serial number at the bottom of the scaleplate?

Dave

[millwright2309]

40632-a-353

[bobbob!]

AVO Multiminor Mk. 5 : 014205

[Chrispy57]

Avo EM272, part number 5170-425, serial number 175771.

Sadly this faulty unit has been steampunked (sensitively I hope) into a Zener diode tester, as described in a post under the Homebrew Equipment section of the Forum!

Cheers
Chris

[Nickthedentist]

Just taken possession of:

AVO Model 8, Mk II.

Serial No: 114874-C-1160.

Thanks for letting me have it, Glyn.

[WaveyDipole]

Likewise just taken posession of an AVO 8 Mk II, thanks to member Anthony. Search the thread but didn't find it mentioned, so here it is:

Serial number: 821940-C-1158.

The movement seems perfectly fine, but the case is damaged and will require repair, but otherwise looks quite clean.
The battery cover is made of Bakelite rather than the usual black metal plate.

[The Philpott]

-Shortly after this there was a general change from bakelite battery covers to metal ones.
Sometimes it seems like a good idea to use a later cover on an earlier meter- until you find the holes don't quite line up. The difference is so small that i think it was accidental; possibly a slight shift in the setup of the jig.

Dave

[AndyGilham]

Hi all, it's been a long time since I've logged in......work and life has taken priority....even over Avometers.
The Avometer collection in Dover continues to grow........all currently stored in a room full to the brim of everything Avo or Evershed.
I recently received a call from a lady who's father was a field sales rep for Avo from 1958 to 1981. Sadly he passed, but had a large collection of meters and documentation. She kindly donated a number of his meters to Megger, so I visited her to pick up 15 meters and approx. 8 boxes full of documents, notes, guides, service manuals.....I still need to sort it all

Andy

[Barnmead]

Welcome back
Good to hear that collection is expanding.

[AndyGilham]

Thank you Richard. I hope you are well.

I am still very annoyed that I was unable to received your collection, it would have really added something special. Unfortunetely it was the wrong time and wrong personal involved to be able to come and collect them. A loss for me and for Megger.

Andy

[The Philpott]

Hi Andy, nice to hear from you. My Protimeter and Type H Universal Avominor have yet to be attended to, the Type H has a problem with the moving coil carrier binding against the cylindrical 'former' when towards the top end of the scale. Unlikely to be fixable, but we'll see.

Dave

[Phil G4SPZ]

Dave, you mention the “Type H Universal Avominor”. I have previously commented on the existence of at least four different models of that instrument, in my small collection anyway, but I didn’t know there were official designations. Can you point me towards the relevant information, please?

Many thanks,

[The Philpott]

Phil, quite apart from the Model 1 meters that went to the military with 'ZD' or 10S/46 references incised and white infilled, (which you've no doubt seen) the Type H Model 1 variant has a special instruction plate denoting it as a Type H.

Richard Allen notes detail differences in the switch assy, but it's basically a Model 1.
(ref- 'Richards Radios')

I'd like to have a closer look at mine but the weather's just turned and it's in the workshop..i know it has the earlier type facia design with finger guards around the terminals.

So...we know we have Type E and Type H variants..perhaps the others never even existed in principle, or just never got off the drawing board.

Dave

[Phil G4SPZ]

Thanks, Dave. I will run through mine later and check what I’ve got. I vaguely recall that there was a high resistance version of the Minor, and I think I might have one.

Universal Avominors are conveniently small enough to keep in one’s toolbox! I used one in this way for several years till a MultiMinor came along.

[The Philpott]

Yes, there is the Model 2 which is 4000 ohm/volt compared to Model 1 400 o/v. Also a Model 1A with a low resistance scale- but electrically identical to a Model 1!
The movement of the Model 2 is noticeably better damped, and i believe that this makes it ever so slightly less accurate than a Model 1; the drag isn't conducive to the pointer always settling at exactly the right spot. (Nit picking really; they're close enough)

If we're talking DC Avominor, there's a 20kohm/volt example which had a limited production run. Curiously the pointer on these is NOT heavily damped; around 4 swings to settle.

Dave