[sdiy] how to tell metal film resistors?

[Roman Sowa]

It's not only tolerance of selecting values at factory, but the resistor 
must keep its resistance within specified tolerance when  considering 
aging and tempco. That's why there are no 0.1% resistors with tempco 
higher than 100ppm, but 25ppm is more common at that precision.
And it's very rare to find a carbon resistor with tempco less than 100ppm.

W dniu 2015-04-27 o 17:55, Neil Johnson pisze:
> Hi,
>
> Quincas wrote:
>> Metal film has different color coding for the value, one extra line to allow for a digit after the period. Check out this page:
>> http://www.musicfromouterspace.com/index.php?CATPARTNO=NONE&PROJARG=ELECTRONICS%2FRESISTORS%2FRESISTORS.php%3Fa%3Da&MAINTAB=SYNTHDIY&SONGID=NONE&VPW=1024&VPH=542
>
> Oh dear... no, sorry, that page is only partly correct, but there is
> no reason you cannot have 1% tolerance carbon film resistors with 5
> bands, or even 0.1% tolerance with 6 bands.  You just pay more money
> to the factory and they sort them out for you. Whether you'd want to
> is another matter, but there is nothing to say you can't.
>
> Neil
> --
> http://www.njohnson.co.uk
>