Capacitor from April 1891 - UK Vintage Radio Repair and Restoration Discussion Forum

David Goodall · 21st Sep 2018, 8:45 pm

Apologies, I have absolutely no idea where to post this question, so I will plonk myself down here and wait to be moved on!
Does anyone have information on this component? There is a possible connection with trans Atlantic cables from this time, but that's all I know. A friend from my village inherited it from a family member that used to write for Wireless World before the war.

Herald1360 · 21st Sep 2018, 9:11 pm

The shorting link and precise value suggests perhaps use in some kind of bridge for measurement purposes.

Maybe enquire of the Telegraph Museum at Porthcurno?

It's a beautiful paperweight!

https://telegraphmuseum.org/contact/

David Goodall · 21st Sep 2018, 9:31 pm

Thank you. I shall contact them.

Graham G3ZVT · 21st Sep 2018, 10:05 pm

"Brass Telegraph Telegraphy Military Morse Code Capacitor", which doesn't make a great deal of sense to me.

http://ancientpoint.com/inf/189306-m...capacitor.html

Some similar?
https://www.antiques-atlas.com/antiq..._box/as172a435

https://www.univ-brest.fr/instrument...-Muirhead---Co

One looking very similar to yours attributed to "Nalder Bros. & Co., London. 1910" (sixth image)
https://www.aber.ac.uk/cy/phys/outre...m/museum-inst/

ms660 · 21st Sep 2018, 10:41 pm

Muirhead and Taylor were involved with undersea telegraph cable systems.

Looks like it might be a capacitor, the test date as you probably know was 29th April '91, two values given, one at 15 deg. centigrade and one at 17 deg. centigrade with the percentage increase in value per 1 degree centigrade increase given as 0.05%, 0.3876 + 0.25% = 0.3885, near enough if my maths interp./attempt is right.

Lawrence.

dsergeant · 22nd Sep 2018, 6:40 am

This may be something the Museum of the History of Science may be interested in:
http://www.mhs.ox.ac.uk/
If you have never been there, they have a large collection of early Marconi gear in the basement which is fascinating (basement seems currently closed for refurbishment). A couple of Muirhead items come up in their collection search but nothing like yours.

David Goodall · 22nd Sep 2018, 10:14 am

This has all been very helpful. Thank you.

21st Sep 2018, 8:45 pm	#1
David Goodall Pentode Join Date: Mar 2006 Location: North Norfolk, UK. Posts: 181	Capacitor from April 1891 Apologies, I have absolutely no idea where to post this question, so I will plonk myself down here and wait to be moved on! Does anyone have information on this component? There is a possible connection with trans Atlantic cables from this time, but that's all I know. A friend from my village inherited it from a family member that used to write for Wireless World before the war. Attached Thumbnails __________________ David Goodall

21st Sep 2018, 9:11 pm	#2
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Capacitor from April 1891 The shorting link and precise value suggests perhaps use in some kind of bridge for measurement purposes. Maybe enquire of the Telegraph Museum at Porthcurno? It's a beautiful paperweight! https://telegraphmuseum.org/contact/ __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

21st Sep 2018, 9:31 pm	#3
David Goodall Pentode Join Date: Mar 2006 Location: North Norfolk, UK. Posts: 181	Re: Capacitor from April 1891 Thank you. I shall contact them. __________________ David Goodall

21st Sep 2018, 10:05 pm	#4
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 18,715	Re: Capacitor from April 1891 "Brass Telegraph Telegraphy Military Morse Code Capacitor", which doesn't make a great deal of sense to me. http://ancientpoint.com/inf/189306-m...capacitor.html Some similar? https://www.antiques-atlas.com/antiq..._box/as172a435 https://www.univ-brest.fr/instrument...-Muirhead---Co One looking very similar to yours attributed to "Nalder Bros. & Co., London. 1910" (sixth image) https://www.aber.ac.uk/cy/phys/outre...m/museum-inst/ __________________ -- Graham. G3ZVT Last edited by Graham G3ZVT; 21st Sep 2018 at 10:19 pm.

21st Sep 2018, 10:41 pm	#5
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Capacitor from April 1891 Muirhead and Taylor were involved with undersea telegraph cable systems. Looks like it might be a capacitor, the test date as you probably know was 29th April '91, two values given, one at 15 deg. centigrade and one at 17 deg. centigrade with the percentage increase in value per 1 degree centigrade increase given as 0.05%, 0.3876 + 0.25% = 0.3885, near enough if my maths interp./attempt is right. Lawrence.

22nd Sep 2018, 6:40 am	#6
dsergeant Octode Join Date: Mar 2006 Location: Bracknell, Berkshire,UK. Posts: 1,172	Re: Capacitor from April 1891 This may be something the Museum of the History of Science may be interested in: http://www.mhs.ox.ac.uk/ If you have never been there, they have a large collection of early Marconi gear in the basement which is fascinating (basement seems currently closed for refurbishment). A couple of Muirhead items come up in their collection search but nothing like yours.

22nd Sep 2018, 10:14 am	#7
David Goodall Pentode Join Date: Mar 2006 Location: North Norfolk, UK. Posts: 181	Re: Capacitor from April 1891 This has all been very helpful. Thank you. __________________ David Goodall