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G6Tanuki · 6th Feb 2019, 8:14 pm

No; carbon-composition resistors are made with a solid rod of resistance-material, think of it like the graphite 'lead' in a pencil. The electrons flow through the entre thickness of the rod, so its inductive properties are essentially those of a short rod.

Carbon-film resistors use an insulating ceramic former that is coated with a carbon film deposit (hence the name) and then in many instances a spiral is cut round the body, through the film to lengthen the path so that the current flows spirally round the former.

This spiral construction means that carbon-film resistors are slightly inductive.

Carbon-film resistors do, however, generally produce less thermal noise which is why they're popular in low-signal-level amplification.

6th Feb 2019, 8:14 pm	#8
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 14,007	Re: Identifying resistor types? No; carbon-composition resistors are made with a solid rod of resistance-material, think of it like the graphite 'lead' in a pencil. The electrons flow through the entre thickness of the rod, so its inductive properties are essentially those of a short rod. Carbon-film resistors use an insulating ceramic former that is coated with a carbon film deposit (hence the name) and then in many instances a spiral is cut round the body, through the film to lengthen the path so that the current flows spirally round the former. This spiral construction means that carbon-film resistors are slightly inductive. Carbon-film resistors do, however, generally produce less thermal noise which is why they're popular in low-signal-level amplification.