pete10uk Posted July 24, 2014 Share Posted July 24, 2014 Hi all I'm trying to ID and replace variable resistor which has fallen apart through use, mostly down to the fact the wrong tool has been used. I can't see any markings only perhaps 1K but this may be wishful thinking as the case is scratched. I would ideally like to replace it with a version which has a physical adjuster. I have measured the resistance of the identical looking one next to it, and it reads between .629-.687 which is less than the range I was hoping to see for the a 1K resistor, is this to be expected? Any pointers would be appreciated. http://www.purplewaveav.com/wp-content/uploads/2014/07/BR-Resistor.jpg Link to comment Share on other sites More sharing options...
Andrew C Posted July 24, 2014 Share Posted July 24, 2014 If you don't take the resistor off the board, you are measuring the resistance of all possible paths, thus lower than you might expect. Hope I'm not teaching egg-sucking... Link to comment Share on other sites More sharing options...
J Pearce Posted July 24, 2014 Share Posted July 24, 2014 Or to make life easier in some cases, one end of the resistor off the board. Link to comment Share on other sites More sharing options...
pete10uk Posted July 24, 2014 Author Share Posted July 24, 2014 If you don't take the resistor off the board, you are measuring the resistance of all possible paths, thus lower than you might expect. Hope I'm not teaching egg-sucking... Thanks, No your not! I can swap parts and solder them back on with some quite neat soldering at times but the parts them selfs, apart from the basic operation has never been my strong point my brain just doesn't work that way. Just removed the good one from the circuit but unfortunately that one has also now fallen to bits. A bit of a design error as the pots as solid from the other side, the damage has occurred when using the wrong sized screw driver to make adjustments, which now means that you have to press on with too much pressure to get a grip and the force has just pushed the pot apart. If they were fitted the other way around that wouldn’t be an issue. The second one also has something resembling a 1K mark so I think we'll try that. * Edited as the 1KL was a mistake Link to comment Share on other sites More sharing options...
J Pearce Posted July 24, 2014 Share Posted July 24, 2014 That'll be a linear pot, a logarithmic pot would be 1kA. Link to comment Share on other sites More sharing options...
Peter18 Posted July 24, 2014 Share Posted July 24, 2014 You can measure the resistance on the 'outer' cover of the bits - the detached part in the foreground of the photo. The carbon track that defines the resistance is between the two metal contacts. The rest (still on the board) is just the wiper arm and support.Pin dimensions and spacing may limit your choice of replacement... Link to comment Share on other sites More sharing options...
pete10uk Posted July 24, 2014 Author Share Posted July 24, 2014 That'll be a linear pot, a logarithmic pot would be 1kA. Yes it does have an L on it as well. Sorry the 1KL on my previous post the L was an error I have managed to reassemble to good one again and it has a range of 0-.85 allowing for a tolerance on my cheap meter and manufacturing I'd say that's a 1K. I'll have a good look around for a replacement. thanks Link to comment Share on other sites More sharing options...
Oldradiohand Posted July 27, 2014 Share Posted July 27, 2014 And when it's fixed invest in some proper tweakers - you'll find them listed as "potentiometer adjusting tools" Much better than screwdrivers. Link to comment Share on other sites More sharing options...
DrummerJonny Posted July 28, 2014 Share Posted July 28, 2014 And when it's fixed invest in some proper tweakers - you'll find them listed as "potentiometer adjusting tools" Much better than screwdrivers. I've had one of those sat on my desk for ages - never worked out what it was for! Thanks! Link to comment Share on other sites More sharing options...
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