[Elecraft] Carbon Composition Resistors - Aging

[Jack Smith]

Unlike fine wine, carbon composition resistors do not get better with age.

I ran across a couple hundred brand new carbon composition resistors 
manufactured around 1960 while looking for something else today and 
spent a couple hours measuring them to see how badly they had drifted. I 
found the results interesting enough to add a page on the measurements 
at http://www.cliftonlaboratories.com/carbon_composition_resistors.htm.

There may be reasons to keep 50 year old carbon composition resistors 
around, such as restoring period radios, but these parts do age poorly, 
even when "new old stock." Before using one, I would carefully check the 
value as odds are good it will not be in tolerance.

Jack K8ZOA
www.cliftonlaboratories.com