Resistors

[littlerick]

Been going through my component mountain and have come accross some large resistors that send my multimeter mental.

I have one 4 bands green, blue, yellow, gold.... my pc resistor colour guide says 560k.... my multimeter just jumps about like its on drugs. All my smaller resistors have worked fine.

Now some of these resistors could be upto 45 years old as they all came from my father in laws shop before he died. Do they have a shelf life and will a dodgy resistor do this to multimeter.

 

[DF96]

Some old components can develop intermittent contacts, or have tarnished leads. Either can confuse a meter. The former means bin it; the latter means just clean the leads.

 

[littlerick]

ok thanks... better get a cloth ready eh... got bloody thousands of the things. Also got some that are made from some sort of clay or pot. Are they any good for regular applications or are they for a particular job?

 

[DF96]

Some pictures might help.

 

[AndrewT]

if the leads are silver plated or tinned then a dab with a hot soldering iron completely removes the oxidation and replaces it with a thicker soldered (tinned) end that conducts properly.

gold is 5% tolerance. be prepared to do matching when you build.