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ColinTheAmpMan1 · 3rd Feb 2019, 1:16 pm

I have come by a whole collection of resistors (10 off of values from 10R to 10M in the E12 series), which I am hoping (don't ask why!) are carbon composition. Is there any way of ascertaining the type of a resistor, carbon comp., carbon film, metal film, metal oxide? I realise that all but the carbon comp. types will have some inductance, but is that measurable?

The resistors came in a box marked "Pop's Electronical Shop" in Croydon. The 'phone number of this establishment is given with an 01- prefix, which indicates to me an approximate date of packing, at least. The resistors are rated at 1/4W and 5%. They are bandolier mounted and about the same size as a modern metal film type (6mm x 2mm). Since they are all bagged and boxed together, they are probably all the same type.
Any ideas?
TIA, Colin.

P.S. I am interested in carbon comp. resistors because I repair, make and generally mess about with valve amplifiers, etc. and like to keep them as original as I can.

3rd Feb 2019, 1:16 pm	#1
ColinTheAmpMan1 Octode Join Date: Jan 2012 Location: Wimbledon, London, UK. Posts: 1,465	Identifying resistor types? I have come by a whole collection of resistors (10 off of values from 10R to 10M in the E12 series), which I am hoping (don't ask why!) are carbon composition. Is there any way of ascertaining the type of a resistor, carbon comp., carbon film, metal film, metal oxide? I realise that all but the carbon comp. types will have some inductance, but is that measurable? The resistors came in a box marked "Pop's Electronical Shop" in Croydon. The 'phone number of this establishment is given with an 01- prefix, which indicates to me an approximate date of packing, at least. The resistors are rated at 1/4W and 5%. They are bandolier mounted and about the same size as a modern metal film type (6mm x 2mm). Since they are all bagged and boxed together, they are probably all the same type. Any ideas? TIA, Colin. P.S. I am interested in carbon comp. resistors because I repair, make and generally mess about with valve amplifiers, etc. and like to keep them as original as I can.