12th Jun 2015, 10:38 am | #1261 |
Triode
Join Date: Feb 2015
Location: Derby, Derbyshire, UK.
Posts: 18
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Re: AVO Multimeter survey
Hi.
first time posting on a forum so hope it works OK. I've been colecting AVOs for few years and have been reading other posts on here with great interest. Ive got about 10 AVOs a model 40 from Feb 1944 in a box with the shunts & voltage multiplier, 3 or 4 model 7s, an AVO test bridge meter (sadly not working damaged in the post) an DC AVO Minor, a universal AVO Minor (with box & leads), A number 1 high sensitivity meter, a Multiminor mk5 (in great condition with leeds case & instructions. My latest buy was a 13 range model no 2 which seems to work but the needle on it does not return properly. On looking inside ,it looks like the hair spring is damaged. Meter no.3759. Would greatly value any help or info on the meter or how to fix the spring. Will try & put a full list of meters and serial numbers together and post it. Have attached some pics (hope it works). |
15th Jun 2015, 7:22 pm | #1262 |
Dekatron
Join Date: Mar 2008
Location: Worthing, West Sussex, UK
Posts: 5,185
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Re: AVO Multimeter survey
I have just added another Avo to my collection, this is a model 9 mk4.
It is mint and boxed, complete with instruction book and accessories. Serial No 2669-1V-170. Mark |
16th Jun 2015, 11:51 pm | #1263 |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
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Re: AVO Multimeter survey
Just been given an 8 Mk:III by a former TV repairman who used it in his employ for a well-known but long-departed Workington TV dealer and repair business.
Serial No: 43288-666 A go-er and accurate, but needed balanced, and the pointer flies hard over -VE when Ohms or Ohms / 100 are selected at the same time as 50uA!
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Regds, Russell W. B. G4YLI. |
18th Jun 2015, 11:18 pm | #1264 | |
Dekatron
Join Date: Apr 2005
Location: Bewdley, Worcestershire, UK.
Posts: 4,736
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Re: AVO Multimeter survey
Quote:
Phil
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Phil Optimist [n]: One who is not in possession of the full facts Last edited by Phil G4SPZ; 18th Jun 2015 at 11:30 pm. Reason: Forgot attachment |
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18th Jun 2015, 11:28 pm | #1265 |
Dekatron
Join Date: Apr 2005
Location: Bewdley, Worcestershire, UK.
Posts: 4,736
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Re: AVO Multimeter survey
Model D, serial number D 2104-541. This is a real oddball, being a Model D but based on a Model 7 panel rather than the usual Model 40, and having a 1mA movement! I am just embarking on a detailed investigation. I can only assume that demand from the Air Ministry in 1941 was so great that Avo were forced to use whatever panels and movements were available. This instrument shows signs of previous repairs...
Phil
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Phil Optimist [n]: One who is not in possession of the full facts |
20th Jun 2015, 10:02 pm | #1266 |
Triode
Join Date: Feb 2015
Location: Derby, Derbyshire, UK.
Posts: 18
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Re: AVO Multimeter survey
Thanks Phil for the extract from the Avo's Servicing Information, will give that a try. below is list of the Avos I have
1-DC Avometer 13 range, model 2. No. 3759 (some where between 1927 & 33 I think) as mentioned in last post. 2-Universal Avo Minor No. 61469-1143 not working, possible hair spring damage. 3-Universal Avometer Admiralty Pattern 48A, with box shunts & voltage multiplier No. 13810-244, Fully working & in good condition. 4-Avo Minor No. 81783-646 fully working with leads & instructions. 5-Universal Avo Minor No. 101817-347 fully working with leads & instructions. 6-Avo Test Bridge No. 6504-647 (damaged in post, needs new valve & has case damage) 7-Universal Avometer Model 7 No. 229-A1061F some ranges not working. 8-Universal Avometer Model 7 No. 7141-4862 some ranges not working. 9-No1 High Sensitivity No. 5358 169 fully working with leads & case 10-Universal Avometer Model 7 No. unknown, has had replacement movement fitted working. 11-Multiminor mk5 No. 37418 fully working with leads instructions & case. I also have 6 or 7 Evershed & Vignoles meters does any one know if there is a thread for them. or any dating info for them. |
20th Jun 2015, 11:19 pm | #1267 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: AVO Multimeter survey
There isn't a collective thread for Evershed & Vignoles instruments, but if you type Evershed into the search box above you will find several individual threads. You may start a new thread if you so wish.
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29th Jun 2015, 6:00 pm | #1268 |
Retired Dormant Member
Join Date: Jun 2015
Location: South Buckinghamshire, UK.
Posts: 5
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Re: AVO Multimeter survey
Multiminor Mk 5 27048
Travelled all around the World and still does. |
29th Jun 2015, 11:59 pm | #1269 |
Banned
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,704
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Re: AVO Multimeter survey
Everyday meter!! Model 8 MKII
Serial number 166161-C-1163. Not the engraving on the left, SMA ( Snowy Mountains Authority) E&M ( Electrical and Mechanical division) and their plant number 324096. I would be lost without this!!. I do have a multitude of others, including digital, NOTHING beats the ease of the Avo. Joe |
30th Jun 2015, 9:22 pm | #1270 |
Tetrode
Join Date: Jun 2014
Location: Plymouth, Devonshire, UK.
Posts: 70
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Re: AVO Multimeter survey
hi all.
I have two avo's a model 7 mk 2 well used metal cased example serial xxx88-A-456 working but under reads a bit i paid £10 from a junk shop. and a model 8 mk 5 very good order,plastic case though only three ranges printed on the scale serial number xxx67 8V/5/77 i paid £15 from the same junk shop. regards Darren. |
11th Jul 2015, 4:04 pm | #1271 |
Triode
Join Date: Mar 2014
Location: Cheshire, UK.
Posts: 27
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Re: AVO Multimeter survey
Russell WB,
I think the main switch contacts are misaligned. You could loosen the screw central screw on the offending switch a little and push the moving contact with a flat bladed screw driver to get better alignment with the fixed contacts. look carefully to see whether or not the rotor aligns with the static contacts at the detent positions other wise you get strange effects as you described. Plan B is to check the leaf spring contacts which is best done by careful comparison with a known good meter to see if they lift and close in the right way. Adjustment is then a matter of cocktail sticks and long nosed pliers. I have sucessfully restored a number of Avos but they require extreme attention to detail! |
12th Jul 2015, 7:07 pm | #1272 |
Dekatron
Join Date: Jul 2007
Location: Penrith, Cumbria, UK.
Posts: 3,684
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Re: AVO Multimeter survey
Pthomas,
I did that shortly after I wrote that post! Sorted it now. When I looked at the service manual it showed where to set the cams and one of mine was out slightly, so I loosened the screw on the 'd.c. switch' and pushed it round a tad's nadger until the contacts raised fully. It now works perfectly.
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Regds, Russell W. B. G4YLI. |
14th Jul 2015, 11:51 am | #1273 |
Diode
Join Date: Jul 2015
Location: Salisbury, Wiltshire, UK.
Posts: 5
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Re: AVO Multimeter survey
Re Avo Survey
Hi This is my first post and my Avo collection is as follows Mod 7 ser no 7xx5 20488 needs new movement Mod 7 ser no 7x6x 30063 good working order Mod 7 Mk 11 ser no 8xxx2 A 1258 good working order small chip on one side where it's been removed from case. Mod 7 Mk 11 ser no 6xxxx8 A 1256 good working order Mod 40 Mk 11 ser no 1xx0 8 467 m needs new movement Mod 8 Mk 11 1xxxx1 c 962 working order but reads low on dc voltage (ex mod) Mod 8 Mk 5 no ser no works ok had to repair pcb in a couple of places Mod 8 Mk 5 ser no 0xxxx3 8v good working order All bought second hand. |
20th Aug 2015, 9:16 pm | #1274 |
Pentode
Join Date: Dec 2002
Location: Norfolk, UK.
Posts: 168
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Re: AVO Multimeter survey
Several more avos have come my way:
model 2 ser no 3474 no terminal version aluminium case model 2 ser no 6540 black terminal version aluminium case model 47A ser no 8067-342 bakelite case model 40 panel moulding model 40 ser no 40185-642 aluminium case model 8 see no 45836-c-456 bakelite case DC AVOminor ser no 77760-146 3/6mA version DC AVOminor ser no 48083-48 Universal AVOminor ser no U22080-95 I tam gradually working through them, the two earliest now work, I have yet to seriously look at the rest.
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Richard |
20th Aug 2015, 10:28 pm | #1275 |
Octode
Join Date: Jul 2004
Location: Dundee, UK.
Posts: 1,797
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Re: AVO Multimeter survey
An interesting sub-collectin Richard, especially to have "come your way" -.you must be very attractive to Avometers.
Could you give some more information on the DC models please? Is 3474 Rochester Row or Douglas Street production and could you post pictures of them please? I suspect that the second one, with the black terminals, has been modified; if not it could be quite a rare one. PMM |
20th Aug 2015, 10:42 pm | #1276 |
Pentode
Join Date: Dec 2002
Location: Norfolk, UK.
Posts: 168
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Re: AVO Multimeter survey
They are douglas street and came as part of a collection of instruments that someone had amassed over many years.
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Richard |
20th Aug 2015, 10:49 pm | #1277 |
Pentode
Join Date: Dec 2002
Location: Norfolk, UK.
Posts: 168
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Re: AVO Multimeter survey
I had to make a new scale for one as the paint had cracked. There were two open circuit resistors which are now fixed but otherwise both meters function but I won't vouch for accuracy.
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Richard |
21st Aug 2015, 11:47 am | #1278 |
Pentode
Join Date: Mar 2007
Location: Croydon, London, UK.
Posts: 111
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Re: AVO Multimeter survey
The D.C Avometer with the black terminals is in fact a rare model 6 as defined by PMMUNRO
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21st Aug 2015, 12:49 pm | #1279 |
Octode
Join Date: Jul 2004
Location: Dundee, UK.
Posts: 1,797
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Re: AVO Multimeter survey
Richard,
As Michael has told you, your second DC Avometer is the 22-range version which is one of the rarest of all Avometers. Your luck was certainly in when that one found you! PMM |
22nd Aug 2015, 9:25 am | #1280 |
Pentode
Join Date: Dec 2002
Location: Norfolk, UK.
Posts: 168
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Re: AVO Multimeter survey
Thank you both for identifying it and letting me know that I need to look after it! The instruction plate on the back( if I had looked) confirms that there are 22 ranges available. When received it had a Siemens size S battery which took a great deal of effort to remove and the terminals were absent. I replaced the latter with 4BA screws with heads removed and two terminals from a defunct Cambridge instrument.
I guess this one must date from about 1936/?
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Richard |