UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - First Radio Build

TonyDuell · 17th Jul 2017, 6:42 pm

Assuming all pots are either log or linear law (there are other laws, some quite exotic, but you are unlikely to come across them) :

Set the pot spindle to the mechanical mid postion.

Measure the resistance between the wiper (middle terminal ) and each of the outside 2 terminals.

If the 2 resistances are about the same (and equal to half the nominal resistance of the pot) then it's a linear law one. If they are wildly different it's log law.

[Crossed with MS660]

17th Jul 2017, 6:42 pm	#30
TonyDuell Dekatron Join Date: Jun 2015 Location: Biggin Hill, London, UK. Posts: 5,208	Re: First Radio Build - 12V HT system Assuming all pots are either log or linear law (there are other laws, some quite exotic, but you are unlikely to come across them) : Set the pot spindle to the mechanical mid postion. Measure the resistance between the wiper (middle terminal ) and each of the outside 2 terminals. If the 2 resistances are about the same (and equal to half the nominal resistance of the pot) then it's a linear law one. If they are wildly different it's log law. [Crossed with MS660]