Any Vintage Multimeter Aficionados? - Page 1
Forum section: electronics / general

author: icon
author_rank: Regular Contributor
timestamp: June 15, 2012, 10:19:26 pm
content: HiThis multimeter came my way. The donor told me about it before I saw it, and I assumed from his description that it was going to be an AVO of some sort. I was surprised to find that it was a Sangamo Weston - not a name I associate with meters. I've had a look on t'internet but I can't find a single reference - can you do better?Anyway, it might be from 1959 (judging by the meter) or 1955 (which is stamped on the bottom of the rather nice leather case it came in). I wish I could attach a sample of the smell of the meter. It smells like.... old electrical stuff. They just don't make electrons like they used to.I took it apart, partly out of curiosity and partly to clean it up a bit. Here are the photos:A very clean dial with mirror. Hidden by the case is the shameful text "500 Ohms/V". Fans of solid detents would rejoice in these knobs. The connectors are binding posts - I did think about fitting 4mm sockets, but thought I'd leave the old lady in her original form.There's some kind of sprung switch on the side there; a bimetallic thing? Who knows.A cavernous battery bay. It takes a 1.5V cell and 4.5V battery. I've no idea what type. Someone's had a bit of a go bodging a wire in there at some point. The negative terminals for the cell/battery are binding posts, for goodness sake.I've checked it on DC volts up to about 20V. As near as I can tell the accuracy varies from 0.1% to 0.5% depending on the range. I haven't tried current yet.If anyone can point to any source of information, I'd be grateful.CheersJohn

author: free_electron
author_rank: Super Contributor
timestamp: June 15, 2012, 11:56:45 pm
content: If you need help grinding it to fine powder , casting the remnants in concrete and burying it, let me know. i'm pretty good at 'widlarizing' dinosaurs.before the flame war starts : ITS a JOKE !i understand some people have nostalgic feelings about old stuff. Nothing wrong with that.I just relate 'nostalgia' with 'everything as better in the old days' .. like when there was famine , war , pestulence, crusades and witchhuntsJudging from the pristine innards and non-discolored wires this must come from some lab or have sat in a display case most of its life. or used by a schoolteacher who took it out once a year to give a demo with it.i like also the flame-inhibiding tubes over what looks like the range resistors for the divider.

author: amspire
author_rank: Super Contributor
timestamp: June 16, 2012, 12:26:22 am
content: I cannot tell you about that particular meter, but Weston is the most famous name in moving coil meters.Edward Weston was an English born American who was one of the great geniuses of the late 19th and 20th centuries. He invented the way to make practical long-life carbon filament lamps, but due to the stupid patent laws, he had to give the technology to Edison who was famous for having the best lawyers.Weston designed the first accurate moving coil meters, along with the mercury standard battery that was the standard for voltage for half the 20th century, zero temperature coefficient resistance wire and a heap of other things. He was a genius in Electronic measurement, Chemistry, Metalurgy - basically whatever he put his mind to.Weston Electrical Instrument Co. of Surbiton, Surrey was the English subsidiary of the Weston Electrical Instrument Corporation in the US. In 1936 - the year of Edward Weston's death - it was acquired by British Sangamo. British Sangamo was a subsidiary of the Sangamo Electric Co. of Springfield, Illinois.Sangamo Weston was sold to Schlumberger in 1976.This meter was built in an era when people worked at the one company for their working life, so for sure, the designers of this meter had worked directly with Weston's designs, and perhaps worked directly with Weston. Looks like a very fine meter, and I am sure it is still a great meter to use.I would guess the 1.5V battery is a D cell. Not sure about the 4.5V battery. The common one for the 60's was the 4.5V Bicycle Lamp battery that looks like it is still available:http://www.master-instruments.com.au/products/61491/MN1203.htmlNot sure how it would connect to the terminal posts unless the battery fitted into a removable holder that is missing now.Richard.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 16, 2012, 03:14:00 am
content: There was one of these in the instrument cupboard at the AM Broadcast Transmitter I worked at years ago.It never fired a shot in action AFAIK.We always used the AVO model 8s,& occasionally a Simpson.The Weston just sat there looking pretty.

author: amspire
author_rank: Super Contributor
timestamp: June 16, 2012, 03:27:18 am
content: Quote from: vk6zgo on June 16, 2012, 03:14:00 amIt is only 500ohms/volt. I think it is aimed more at the power industry.Not a good meter for working on electronics. If you had an 20K Ohm/Volt Avo 8 or Simpson, you would definitely grab them first.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 16, 2012, 03:50:33 am
content: Quote from: amspire on June 16, 2012, 03:27:18 amThen again,Richard,a lot of the guts of Broadcast Transmitters are closer to power industry stuff than what we would normally label "Electronics"I agree,though that the AVO & Simpson were the more appropriate device,as they were good for both heavy power supply stuff&chassis level Electronics,in tube & early solid state stuff.Their huge test leads are not the best for board level work,but we could use Oscilloscopes & VTVMs instead,so it wasn't that great a limitation.AVO 8s are the only multimeter I've ever seen with a 2500v range!When measuring in high energy circuits, these big analog meters,were usually placed on the ground,as they were so damn heavy,& the operator read them from a meter or so away.This, combined with their very heavy construction,made them quite safe to work with,providing that you always made sure your test leads were OK,as very old ones had a habit of perishing.The newer ones used a different formula,& didn't seem to have that problem.

author: IanB
author_rank: Super Contributor
timestamp: June 16, 2012, 05:55:39 am
content: I grew up near Enfield and as I child I used to travel past the Sangamo Weston factory on the Great Cambridge Road quite regularly. The name is engraved on my memory from seeing it so often.Another contemporary name adorning a factory nearby was Thorn, well known in consumer electronics. A name that has also now faded into history.

author: Kilroy
author_rank: Regular Contributor
timestamp: June 17, 2012, 02:35:24 am
content: Quote from: vk6zgo on June 16, 2012, 03:14:00 amI have a Bach-Simpson 635 that measures up to 6kV AC/DC...highest I've ever seen.

author: Rerouter
author_rank: Super Contributor
timestamp: June 17, 2012, 02:38:27 am
content: I may have to dig it out, but i have an old valve based multimeter (yes multimeter not bench) with a 1 Gigaohm input impedence for measuring from mV to KVbest thing is it was made in sydney australia

author: icon
author_rank: Regular Contributor
timestamp: June 17, 2012, 08:28:25 pm
content: It's an ex-GPO meter. Judging by the case and leads it saw a hard life in service. The meter was filthy before I cleaned it up and you can see that the writing on the knobs is worn to the point where it's tricky to read. But it was incredibly well sealed. There was a bead of some flat woven cord with black goop in a groove round the rim. The glass is sealed similarly round the edge. The battery bay provides no access into the meter.I've checked the DC current and AC voltage and current over the widest range I can go, and it's very accurate. Shame about the Ohms/V.John

author: bsgd
author_rank: Regular Contributor
timestamp: June 17, 2012, 10:57:37 pm
content: I also have a few tube multimeters, one from HP, and others from brands I just cant remeber right now.I also have a few tube scopes, but havent had the time to restore them.

author: Raff
author_rank: Regular Contributor
timestamp: June 18, 2012, 02:06:51 am
content: It looks a lot like the type of meter we used to use in Telecom, the APO Number 2. We had those and a choice of both analog and digital meters with higher input impedance's, but the old #2 wasn't fooled by such tricks as sneaky unsoldered joints creating resistance etc. At 50 volts and with a 10 meg input impedance a digital meter often told you all was well! Ahh the good old days.I seem to remember that the #2 was 1000 ohms / volt.

author: Raff
author_rank: Regular Contributor
timestamp: June 18, 2012, 02:12:54 am
content: Tempted to bid on herhttp://www.ebay.com.au/itm/Australian-Post-Office-APO-No-2-Multimeter-/170856948830?pt=AU_Electronics_Vintage_Electronics&hash=item27c7de245e

author: vk6zgo
author_rank: Super Contributor
timestamp: June 18, 2012, 04:45:53 am
content: I think we had one of those,too at 6WF,may have been in the"old building"When I was there,the "new" building was 20 years old!We were a little known part of PMG/Telecom,who loooked after ABC,& some Commercial ,transmitters.

author: Raff
author_rank: Regular Contributor
timestamp: June 18, 2012, 05:13:30 am
content: Ahh yes thats right, long long ago Telecom / PMG used to look after the ABC's gear, around here, Southport, Queensland, there was good old 4SO on 1596KHz, all the local telephone exchanges had an amplifier connected to we could "monitor" 4SO. I went there once when I was an apprentice, it was great! I miss 4SO and good old 4GG, my crystal sets lay quiet these days4GG became 4GGG after the switch to FM, and is now known as GOLDFM, its just not the same

author: vk6zgo
author_rank: Super Contributor
timestamp: June 18, 2012, 06:43:16 am
content: If it was the same as in West Oz,the Telephone techs used to do "First-in Maintenance",& if it was a really hard fault,a team from the Broadcast Branch would come up & fix it.I flew, & drove,many km doing that stuff!You'd be away on a maintenance run,& the Boss would contact you to say; "While you're in the area"-----& send you off to somewhere 300km away from where you were!Toyota HiAce seats got a bit uncomfortable after the first 5 or 6 hundred km!The Fly-ins were a bit more civilised,though!Most of the places we went had some sort of Telecom presence.Not like today,where country towns have been denuded of staff from all sorts of organisations,-----No Telstra,Railways,Banks,& in some cases,even Cops!

author: SeanB
author_rank: Super Contributor
timestamp: June 18, 2012, 04:26:45 pm
content: Sound like where I used to stay...... The local shop was a 200km round trip. Used to phone KFC and place an order and drive to collect it, generally when we arrived to collect they would close up and go home, having stayed open the extra hour it took us to get there. Half the order would get eaten on the way back though.

author: T4P
author_rank: Super Contributor
timestamp: June 18, 2012, 05:36:59 pm
content: Quote from: SeanB on June 18, 2012, 04:26:45 pmThat's really-extremely far

author: SeanB
author_rank: Super Contributor
timestamp: June 18, 2012, 06:03:15 pm
content: Scary thing was that there were 3 pubs within either 3 minutes walk, 5 minutes drive or 10 minutes drive. One guy took out a pole ( only bend literally in the road for 40km, and he had to hit the phone line pole on an embankment 5m up the cutting) and disconnected all comms for 2 weeks until the fibre was repaired. He was a little drunk at the time.

author: vk6zgo
author_rank: Super Contributor
timestamp: June 19, 2012, 03:52:11 am
content: Did the Pubs do meals?You might have been better to eat there,instead,but when you get the taste for KFC,you have to have it!When I was in England in the 1970s,I made a round trip of about 200km to London to get KFC one Sunday.(AFAIK the only other place that had it at the time was Liverpool)The Brits quite justifiably thought I was mad!The KFC was cold & served with chips---unheard of in Oz at the time!(I'm still a bit funny about chips with KFC)To make for a more entertaining day,I had trouble with the Ford Popular on the way back--blocked fuel filter.More recently,back home,my missus made a 320k round trip from Quairading to Perth to go to Bingo on a couple of occasions.When I was courting her,she lived 225km away.We don't do stuff like that these days--fuel's too expensive!

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: June 19, 2012, 02:58:40 pm
content: @ Icon ,Love That Sir ,I have ended up buying 15+ in this month in mixed types .Check me smiling with a AVOmeter 8 Mk5 .

author: SeanB
author_rank: Super Contributor
timestamp: June 19, 2012, 03:30:58 pm
content: It looks like new....... Nice to see the same socket outlets as I have in South Africa.

author: Amarbir[Lynx-India]
author_rank: Frequent Contributor
timestamp: June 19, 2012, 03:43:21 pm
content: Quote from: SeanB on June 19, 2012, 03:30:58 pmSean Sir ,You Are Talking Abut Ac Voltage Outlets In My Picture .Lol See what i was showing and see where you keen eye went lol

author: SeanB
author_rank: Super Contributor
timestamp: June 19, 2012, 04:10:52 pm
content: No, the meter is in excellent condition, with an almost in the box look on it. The socket outlets are so close to it, along with the peaceful man doing a sterling job of holding it up for us to view.the workbench, like mine, needs to be uncluttered a little.