What sort of resistor is this..? - UK Vintage Radio Repair and Restoration Discussion Forum

The Philpott · 20th Apr 2019, 6:25 pm

Nickel plated caps on either end, 10,000 printed on the glass and what appears to be a glass rod inside, speckled with dark fragments. At room temperature it measures 9.63kohm so accuracy is not paramount...could it be a fusible resistor?

Dave

HamishBoxer · 20th Apr 2019, 6:35 pm

I think it is fusible,sure I have seen them before.

high_vacuum_house · 20th Apr 2019, 6:44 pm

I was going to say it was an ultra high resistance resistor. The glass envelope there to stop the surface becoming damp/contaminated and lowering its resistance.

I saw a couple of similar ones in a vintage Ekco battery valve Geiger counter years ago with massive resistance values in the input to the detector/amplifier though 10K is not very high so it’s a mystery. Maybe an early attempt for a high stability resistor being sealed in glass.

Christopher Capener

buggies · 20th Apr 2019, 7:38 pm

Bit low for a grid leak - but similar picture here:-
https://mullard.org/products/giant-d...ious-from-1929

G6Tanuki · 22nd Apr 2019, 5:59 pm

Is it actually a resistor? Could it be one of the 'electrolytic' elapsed-hours indicators that were commonplace in things like mainframe-computer hard-disc-drive units, professional tape/video-recorders and the like a few decades back.

The "10,000" could be 10,000-hours?

They're still available - see https://uk.rs-online.com/web/p/hour-meters/0258164/

I fitted these in some of the linear-amplifiers I designed in times-past; one to show 'powered-up hours' and another to show 'actively-delivering-RF-output' hours.

20th Apr 2019, 6:25 pm	#1
The Philpott Dekatron Join Date: Aug 2016 Location: Colchester, Essex, UK. Posts: 4,108	What sort of resistor is this..? Nickel plated caps on either end, 10,000 printed on the glass and what appears to be a glass rod inside, speckled with dark fragments. At room temperature it measures 9.63kohm so accuracy is not paramount...could it be a fusible resistor? Dave Attached Thumbnails

20th Apr 2019, 6:35 pm	#2
HamishBoxer Dekatron Join Date: Aug 2007 Location: W.Butterwick, near Doncaster UK. Posts: 8,935	Re: What sort of resistor is this..? I think it is fusible,sure I have seen them before. __________________ G8JET BVWS Archivist and Member V.M.A.R.S

20th Apr 2019, 6:44 pm	#3
high_vacuum_house Octode Join Date: May 2003 Location: Belper Derbyshire Posts: 1,936	Re: What sort of resistor is this..? I was going to say it was an ultra high resistance resistor. The glass envelope there to stop the surface becoming damp/contaminated and lowering its resistance. I saw a couple of similar ones in a vintage Ekco battery valve Geiger counter years ago with massive resistance values in the input to the detector/amplifier though 10K is not very high so it’s a mystery. Maybe an early attempt for a high stability resistor being sealed in glass. Christopher Capener __________________ Interests in the collection and restoration of Tefifon players and 405 line television

20th Apr 2019, 7:38 pm	#4
buggies Heptode Join Date: Jan 2009 Location: West Lothian, UK. Posts: 762	Re: What sort of resistor is this..? Bit low for a grid leak - but similar picture here:- https://mullard.org/products/giant-d...ious-from-1929 __________________ George

22nd Apr 2019, 5:59 pm	#5
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: What sort of resistor is this..? Is it actually a resistor? Could it be one of the 'electrolytic' elapsed-hours indicators that were commonplace in things like mainframe-computer hard-disc-drive units, professional tape/video-recorders and the like a few decades back. The "10,000" could be 10,000-hours? They're still available - see https://uk.rs-online.com/web/p/hour-meters/0258164/ I fitted these in some of the linear-amplifiers I designed in times-past; one to show 'powered-up hours' and another to show 'actively-delivering-RF-output' hours.