[R-390] The role (if any) of modern resistors within a R390A receiver

[Jim Whartenby]

JohnMost modern leaded components appear to be tined copper over steel wire.  Perhaps your resistors are tinned copper over stainless?  Scrape a lead to see if the underlying metal is still copper.  I personally would not loose any sleep over it. I am sure that the receiver doesn't care either!  <grin>
On the bright side, no more resistor value drift with carbon film!JimLogic: Method used to arrive at the wrong conclusion, with confidence.  Murphy 

    On Monday, July 8, 2024 at 08:30:42 PM CDT, jkharvie via R-390 <r-390 at mailman.qth.net> wrote:   

 I have a confession to make.  

My collection of 200 or so composition carbon resistors that I put together in 1989 for servicing rebuild of receivers is now showing the majority of the resistors have drifted out of 10% tolerance and are not usable.
27 ohm is now 38 ohm
22K is now 32K
etc...
After some review I purchased  a new collection of ~75 values, 5 resistors each.
These are lovely 1 Watt carbon film resistors, good copper leads well tinned, non magnetic per the advertisement.  Look great!

Dimensions:Body is 0.440" long, diameter of 0.157" 
Leads are 0.026", 0.990" longEnd cups on resistor body are 0.165" diameter, ~0.090" wide 

I thought I was out of the woods....
Issue/ question:The manufacturing of these resistors involves use of two "end" caps on the ceramic tube for the transition to the copper wire leads.
I have discovered that these two end caps are made of an alloy that is able to be easily picked up by a magnet.
I am thinking unintentional addition of magnetic reactance to areas of the receiver.

How big an issue is this going to be on the receiver?
1) Not an issue, go ahead and use without concern
2) Return these for a refund
3) OK to use in all areas except for the following areas.

Better options?
thank you

John (N3JKE)
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