|
Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
|
Thread Tools |
21st Sep 2018, 8:45 pm | #1 |
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.
__________________
David Goodall |
21st Sep 2018, 9:11 pm | #2 |
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 |
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 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,723
|
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 |
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 |
Octode
Join Date: Mar 2006
Location: Bracknell, Berkshire,UK.
Posts: 1,173
|
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 |
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 |