I have found that carbon comp resistors which are new, but old stock of
decades, are likely to read high by as much as 50%. However, I have a box
full of older (body-end-dot) dogbone resistors and they seem much less
likely to change value.
It would be interesting to see if the came thing happens to resistors owned
by hams in the dry areas. Perhaps someday historians will use carbon comp
resistors for dating equipment - like counting rings in a tree.
I suspect that, like wine, there are good and bad manufacturing years (and
companies) for resistors and capacitors.
I know a fellow who restores old test equipment. During restoration, he
removes all of the "black-beauty" capacitors, which are almost 100% leaky.
He had a bucket full of them when a friend came ina and told them they are
selling on eBay to audiophools. He now sells them on eBay - fully
disclosing that they are leaky and removed from equipment. Someone thinks
they sound better.
73, Colin K7FM
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