AVO Multimeter survey

[m0cemdave]

Two DA116 meters, owned (but soon to be disposed of) by my radio club, no idea of their previous history:

1030 M90199 (also has sticker 7/85)

and

BD No. 0531745

[Sinewave]

Originally Posted by m0cemdave

Two DA116 meters, owned (but soon to be disposed of) by my radio club, no idea of their previous history:

1030 M90199 (also has sticker 7/85)

and

BD No. 0531745

I'm local to you, I'd be happy to re-home them.

[Superscope]

m0cemdave,

Thanks for the Serial Numbers.
The 7/85 sticker is almost certainly the Manufacture Date of the Meter,
which fits in with the way other AVO products were marked at that time.

Since this is not an Analogue Meter, we don't have so many of them in the Survey.

But we now have Six serial Numbers recorded for the DA 116 including the Two you have just given.

I do intend to produce a Digital AVO supplement to the Survey Document eventually.


Ian

[AndyGilham]

It seems this wonderful thread has gone very quiet! So here I am to liven it up!
After a weeks relaxation in Spain with the family, I returned home too recieve 2 packages and 3 new meters.

1. DC Avo Minor (18251-95) a meter from September 1935, and the first in my list from 1935. This instrument is in good condition and came with hinged wooden, lined case.
The case style is the early straight edge type.

2. HR Avominor (566-141) a meter from January 1941. This is the oldest one on my short list of HR meters, and the second in my collection. This instrument is in great condition and has a stepped case. It came with the standard HR meter hinged double compartment wooden, lined case and two sets of leads

The 2 instruments above were purchase for just £30, a great deal!

3. Avometer Model 73 (to go with my Model 71, EM272, 12D [Telecom] and 12D [PO]
(Model 72 awaiting delivery)

Excuse the single image, Don't seem to be able to add more than 2 on my iPad.

Andy

[The Philpott]

That's an interesting date for the HR Avominor Andy, it takes the production up beyond the cessation of the Battle of Britain, heading for the Battle of the Atlantic! I would be interested to know:

-If it works
-What the resistor arrangement is inside (I would not expect there to be a 20Meg Siemens resistor in there for the 1,000v range, more likely a chain of four 5Meg's in series.) Love to see a picture.

If the movement is in good fettle the needle should only oscillate 3 (or perhaps 4) times before settling. If it flaps around madly there is usually a break in the shunt chain somewhere.

Dave

[AndyGilham]

Dave,
I will have a look when I get into work Tuesday. Not spent much time looking at them, so I will open up and have a nose inside.

Andy

[AndyGilham]

Dave,
I open the DC Avominor HR
It seems to be working fine, I checked a few ranges and look healthy!

In internal construction as you suggest is a series of resistors. The 1000V range does indeed have a series of 4 resistors (5meg) and then connects to a 5th resistor that comes up from the 250V range socket


Andy

[Wanderer]

Mine is an Avo 8 No. 52991-C-1056

Very much in frequent use too! Used this week to find the fault on my 1953 motorcycle.

Cheers,

Peter

[The Philpott]

Thanks Andy, the only significant difference i can see to the other HR's i have looked inside is the piece of black card (probably an insulator/separator) screwed to one of the (otherwise redundant) threaded holes part-way up the moulding. Probably factory fitted.

NB I have an October '38 HR meter which has the stronger step-sided moulding- i assume they must all have had this feature

Dave

[Superscope]

Hi Peter (Wanderer),

Can I just confirm with you that your AVO 8 is a Mk II and not a Mk I ?
The Serial would suggest a Mk II, but I like to confirm Mk's pertaining to the years new Mk's were introduced.

1956 is the year the Mk II was introduced.

Thanks

Ian

[AndyGilham]

Just received a DA116 with case and leads and in good working condition.
Serial Number 05428 116/02/79 (February 1979)

Andy

[AndyGilham]

So, was it a forum member that won the auction bid for the Avometer Model 7 Service Manual?? It looks a lovely and very useful document!

[The Philpott]

As is sometimes the case a request for something on UKVRR forum results in an example appearing for sale elsewhere. If it has been bought by a member one would hope it would be scanned and circulated in due course!

Dave

[AndyGilham]

�� in that case I could really do with an Avo Ohmeter and a O.Y Testmeter.

Andy

[The Philpott]

Indeed, worth a try Andy!

Just purchased a Model 1/15 Universal Avominor, s/n hand painted in as:

^No.U.15/3938-544. First one i have seen with the military arrow on the actual scale-plate.

This is one of those specials where the 250v range is deleted and a 1,500v range added.

This was cheap from a charity/hospice due to it's very poor condition, but did come with a workmanlike home-made box with more than the usual space for leads/clips.

The box and the meter movement are the principle bits that can be salvaged.. the bakelite case has quite unusual areas of damage, the instruction plate is missing, the battery box has been smashed, and there are gouges out of (and a lump missing from) the exterior of the instrument. Confusingly the stanchions/upstands into which the movement screws thread, are largely smashed away from the interior of the case....yet the movement itself is still serviceable despite being barely attached....and why would someone install a replacement movement into a case that was terminally damaged..? so i reason that it's probably the original..

I will take a closer look at the damage but it's almost reminiscent of small shrapnel damage...if it was from a gas explosion i would have expected the glass to be smashed and the needle to be destroyed..but who knows, there can be freakish effects from explosions. Photos to follow.

(It could just be my imagination running wild as per usual..)

Dave

[AndyGilham]

Dave,
That serial number U15.33938-544 is already on my list of Universal Avominors i posted some time ago. It was not detailed on this forum, so I must have found the image on line, so strange that you found it at a hospice...

Andy

[Superscope]

Just to confirm U.15/3938-544 is not in our Database.
At least it wasn't until your last post Dave.

Andy, the Number you quoted has an extra Digit (33938).

Is that a Typo, or is that really another Serial Number?

For information, we currently have Four U15 Prefix numbers for Avominors.
U.15/134-843
U.15/6076.245
U15/7533-845
U15/1135-1143

Not including any new ones that might appear on Andy's list as I haven't integrated
them into the Master List yet.

Ian

[AndyGilham]

Ian,
That was a typo by me..... opps!
The ones i have logged in my spreadsheet are

U15.134-843
U15.1135-1143
U15.3938-544
U15.6076-245
U15.7533-845
U15.7807.845


Regards
Andy

[Superscope]

This has prompted me to pull my finger out and integrate your List into the Main Survey List Andy.


Couple of questions for you and others, since my knowledge of Avominors is a bit Thin on the Ground!

Regarding the Model E, Model H and Model HR.
Are these distinct Models in their own right, or variations on the Model 1, 1a & 2 ect?


Were the Type H and H.R. only available as DC?


Just so they can be cataloged correctly as a distinct Model in their own right, or a version/Type of
another Base Model.

Regarding the Specials, I obviously haven't been paying attention in Class, what is special about the U15 Series?

When I record the Serial Numbers for any meter, I usually record them exactly as reported.
i.e. If somebody uses a "/" or "-" "."to separate number groups I will normally use the same.
They are exceptions though.

With regards the U15 Series, most the Numbers already reported were in the format U.15/ or just u15/.

On your spreadsheet Andy, the "/" is not used at all.

What is the actual Format used on the Meters?

Thanks in advance for help on the AvoMinors.




The AvoMinors will appear in the next Edition of the Survey Report which I hope to have Ready before the Year End. We currently have 212 AvoMinors Recorded.



Ian

[Sinewave]

I was going to have a few more added to the list, but they got destroyed in the post and one of them were quite rare too. Oh well.