Vintage Voltmeter - UK Vintage Radio Repair and Restoration Discussion Forum

Radio James · 18th Apr 2018, 7:29 pm

I am disposing of some of my father's electronic equipment and came across a PYE Voltmeter (W.G, PYE & Co Ltd, Cambridge, No 23.131). I have attached a couple of photos and would appreciate any advice on what best to do with it.

Any thoughts welcome.

The Philpott · 18th Apr 2018, 8:34 pm

Normally things that have been made for the military have taken a few knocks, but that looks quite good. State of the art for its time.

For research purposes, it might be fun to compare it with a modern digital voltmeter. Does it have any instructions with it?

It's very nice, I wouldn't get rid of it in haste, or to anybody who will steampunk it!

Dave

Cobaltblue · 18th Apr 2018, 8:50 pm

Hi James

Thats very nice

Agree with Dave far to good to be upcycled.

Look for a museum or PYE collector.

Cheers

Mike T

Radio James · 18th Apr 2018, 9:27 pm

No - there are no instructions I'm afraid. I'd be delighted if a museum wanted it but not sure where I would find one with this type of thing.

Refugee · 19th Apr 2018, 12:04 am

It would be nice to see a photo of what is inside it.
It looks like it is more than just a volt meter.

cmjones01 · 19th Apr 2018, 10:36 am

It's interesting that it has a knob labelled 'Sensitivity - Microns' which implies that it's actually for measuring distances in some form. There are 'Galvo' terminals and something else at the bottom left which isn't legible. It's certainly a piece of precision laboratory equipment, but measuring voltage is probably not its purpose.

As for someone who might be interested, what about the Cambridge Museum of Technology? They have lots of artefacts from the Pye companies, being local, and expressed interest in more when I've donated things in the past.

http://www.museumoftechnology.com/

Chris

Sinewave · 19th Apr 2018, 11:12 am

This PYE meter is something I'm interested in also. I'd be delighted to take it into my collection.

I have a real interest and fascination in the PYE range of instruments.

Herald1360 · 19th Apr 2018, 10:27 pm

Something to measure strain gauge outputs, perhaps?

duncanlowe · 20th Apr 2018, 4:13 pm

It could be. Don't they usually use a Wheatstone bridge arrangement?

duncanlowe · 20th Apr 2018, 8:12 pm

Thinking on, I wonder if it's some kind of device for measuring the thickness of a coating. Something like a paint thickness gauge?

Refugee · 21st Apr 2018, 1:12 am

Can we see a photo of the internals of it?

Radio Wrangler · 21st Apr 2018, 4:11 am

Is that a military 'broad arrow' symbol directly under the Pye label?

Microns means distance, so it's intended to go with some sort of transducer. I wondered about an AC voltmeter for a surface roughness gauge, but that wouldn't need coarse, medium and fine backing-off controls.

What I presume are backing off pots or switches have position dots, but no numerical scaling.

But for some sort of DC bridge, wouldn't a centre zero meter be used?

Good puzzle!

David

Refugee · 21st Apr 2018, 4:18 am

I have got a TF1313A and it has not got a centre zero meter but just has an ordinary one in the normal Marconi style.
https://www.vintage-radio.net/forum/...ghlight=TF1313

TonyDuell · 21st Apr 2018, 4:49 am

Quote:

Originally Posted by Radio Wrangler

But for some sort of DC bridge, wouldn't a centre zero meter be used?

There are 2 terminals labelled 'Galvo' which could well be for a centre-zero galvanometer to indicate bridge balance.

Also 2 terminals for 'Battery' (obvious, but what voltage) and 2 which seem to be 'PIRA'. The last could well be the input, but from what? The obvious thing (to me) -- Pirani Gauge (a type of vacuum gauge) -- makes little sense here.

Radio James · 22nd Apr 2018, 2:55 pm

The PIRA is indeed PIRANI, and I believe that it is a military broad arrow under PYE (so ex government equipment). As for opening it I did try but the screws are tight beyond belief and I don't want to damage anything after it's been looked after for 50 or 60 years.

TonyDuell · 22nd Apr 2018, 6:38 pm

The 'Pirani' terminals suggests a vacuum gauge of some type. A Pirani gauge is basically a hot filament in a vacuum system, the lower the pressure the less heat is lost from it. There are 2 ways of running it, either at constant voltage and you determine the pressure from the temperature of the filament (lower pressure - higher temperature) or you keep the temperature of the filament constant and determine the pressure by the power required to do that (lower pressure -- less power needed to keep the fillament hot).

The temperature of the filament was normally determined by measuring the electrical resistance of the filament, which would increase with temperature.

But quite how that relates to the controls on this instrument I do not know.

Sinewave · 23rd Apr 2018, 12:33 am

Evening all, or should I now say good morning, it's been a busy day.

Well, I must thank Radio James for allowing me to re home this beautiful instrument. I'm pleased to add it into my collection.

18th Apr 2018, 7:29 pm	#1
Radio James Retired Dormant Member Join Date: Feb 2018 Location: Sussex, UK. Posts: 10	Vintage Voltmeter I am disposing of some of my father's electronic equipment and came across a PYE Voltmeter (W.G, PYE & Co Ltd, Cambridge, No 23.131). I have attached a couple of photos and would appreciate any advice on what best to do with it. Any thoughts welcome. Attached Thumbnails

18th Apr 2018, 8:34 pm	#2
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,106	Re: Vintage Voltmeter Normally things that have been made for the military have taken a few knocks, but that looks quite good. State of the art for its time. For research purposes, it might be fun to compare it with a modern digital voltmeter. Does it have any instructions with it? It's very nice, I wouldn't get rid of it in haste, or to anybody who will steampunk it! Dave

18th Apr 2018, 8:50 pm	#3
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,864	Re: Vintage Voltmeter Hi James Thats very nice Agree with Dave far to good to be upcycled. Look for a museum or PYE collector. Cheers Mike T __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

18th Apr 2018, 9:27 pm	#4
Radio James Retired Dormant Member Join Date: Feb 2018 Location: Sussex, UK. Posts: 10	Re: Vintage Voltmeter No - there are no instructions I'm afraid. I'd be delighted if a museum wanted it but not sure where I would find one with this type of thing.

19th Apr 2018, 12:04 am	#5
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Vintage Voltmeter It would be nice to see a photo of what is inside it. It looks like it is more than just a volt meter.

19th Apr 2018, 10:36 am	#6
cmjones01 Nonode Join Date: Oct 2008 Location: Warsaw, Poland and Cambridge, UK Posts: 2,677	Re: Vintage Voltmeter It's interesting that it has a knob labelled 'Sensitivity - Microns' which implies that it's actually for measuring distances in some form. There are 'Galvo' terminals and something else at the bottom left which isn't legible. It's certainly a piece of precision laboratory equipment, but measuring voltage is probably not its purpose. As for someone who might be interested, what about the Cambridge Museum of Technology? They have lots of artefacts from the Pye companies, being local, and expressed interest in more when I've donated things in the past. http://www.museumoftechnology.com/ Chris __________________ What's going on in the workshop? http://martin-jones.com/

19th Apr 2018, 11:12 am	#7
Sinewave Octode Join Date: May 2016 Location: Oxfordshire/Bucks borders, UK. Posts: 1,604	Re: Vintage Voltmeter This PYE meter is something I'm interested in also. I'd be delighted to take it into my collection. I have a real interest and fascination in the PYE range of instruments. __________________ Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.

19th Apr 2018, 10:27 pm	#8
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Vintage Voltmeter Something to measure strain gauge outputs, perhaps? __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

20th Apr 2018, 4:13 pm	#9
duncanlowe Nonode Join Date: Jan 2016 Location: Stafford, Staffs. UK. Posts: 2,532	Re: Vintage Voltmeter It could be. Don't they usually use a Wheatstone bridge arrangement?

20th Apr 2018, 8:12 pm	#10
duncanlowe Nonode Join Date: Jan 2016 Location: Stafford, Staffs. UK. Posts: 2,532	Re: Vintage Voltmeter Thinking on, I wonder if it's some kind of device for measuring the thickness of a coating. Something like a paint thickness gauge?

21st Apr 2018, 1:12 am	#11
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Vintage Voltmeter Can we see a photo of the internals of it?

21st Apr 2018, 4:11 am	#12
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,867	Re: Vintage Voltmeter Is that a military 'broad arrow' symbol directly under the Pye label? Microns means distance, so it's intended to go with some sort of transducer. I wondered about an AC voltmeter for a surface roughness gauge, but that wouldn't need coarse, medium and fine backing-off controls. What I presume are backing off pots or switches have position dots, but no numerical scaling. But for some sort of DC bridge, wouldn't a centre zero meter be used? Good puzzle! David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

21st Apr 2018, 4:18 am	#13
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Vintage Voltmeter I have got a TF1313A and it has not got a centre zero meter but just has an ordinary one in the normal Marconi style. https://www.vintage-radio.net/forum/...ghlight=TF1313

22nd Apr 2018, 2:55 pm	#15
Radio James Retired Dormant Member Join Date: Feb 2018 Location: Sussex, UK. Posts: 10	Re: Vintage Voltmeter The PIRA is indeed PIRANI, and I believe that it is a military broad arrow under PYE (so ex government equipment). As for opening it I did try but the screws are tight beyond belief and I don't want to damage anything after it's been looked after for 50 or 60 years.

22nd Apr 2018, 6:38 pm	#16
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: Vintage Voltmeter The 'Pirani' terminals suggests a vacuum gauge of some type. A Pirani gauge is basically a hot filament in a vacuum system, the lower the pressure the less heat is lost from it. There are 2 ways of running it, either at constant voltage and you determine the pressure from the temperature of the filament (lower pressure - higher temperature) or you keep the temperature of the filament constant and determine the pressure by the power required to do that (lower pressure -- less power needed to keep the fillament hot). The temperature of the filament was normally determined by measuring the electrical resistance of the filament, which would increase with temperature. But quite how that relates to the controls on this instrument I do not know.

23rd Apr 2018, 12:33 am	#17
Sinewave Octode Join Date: May 2016 Location: Oxfordshire/Bucks borders, UK. Posts: 1,604	Re: Vintage Voltmeter Evening all, or should I now say good morning, it's been a busy day. Well, I must thank Radio James for allowing me to re home this beautiful instrument. I'm pleased to add it into my collection. __________________ Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.