[ARC5] [External Sender] Resistor Excursions

[Richard Knoppow]

    Up to maybe WW-2 20% resistors were pretty common in radio sets and 
phonographs. It would be interesting to see when 10% parts began to 
become common. Really old radios I've gotten into had solid resistors of 
the dog-bone style, usually with values marked as a body color, an end 
dot and a center dot. They did not appear to be coated. Molded body 
resistors must have shown up c.1940s but don't quote me on that.
    About the best of the CC resistors were the Allen-Bradley, ones also 
sold by Ohmite as Brown devils. IRC also made molded units with an odd 
tree-bark finish but while they advertised heavily I've never seen many 
in old radios. There were several other companies who made molded CC 
resistors, hard to tell them apart and certainly there were low cost 
resistors sold as house brands by large distributors and probably 
directly to manufacturers. Some of these have mold seams on the sides 
and seem to be particularly prone to failure. I have no idea who made them.

On 4/19/2024 5:25 PM, J Mcvey via ARC5 wrote:
> You're right. It's 10%, but certainty not a tight tolerance either..
> In practice, leaky caps do a lot more to degrade the performance than 
> do  the resistors.
> Sure , some go out of tolerance and need to be replaced, but not as 
> abundantly as the caps..
> 
> On Friday, April 19, 2024 at 08:16:00 PM EDT, <scottjohnson1 at cox.net> 
> wrote:
> 
> 
> Silver is 10%, no band is 20%
> 
> Scott

-- 
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998