[R-390] Replacing carbon comps with metal film resistors

[Cecil]

> On Jul 29, 2019, at 10:50 PM, Jacques Fortin <jacques.f at videotron.ca> wrote:
> 
> Hi Perrier, Bob, and everyone else
> 
> Ohmite Carbon Composition:
> 40100 -j 1370
> 
> Philips Metal Film:
> 38980 -j 400
> 
> In this test, at 455kHz, the metal film resistor wins.
> But the surprise is that the Carbon Composition turned out to be the more "imperfect" of the lot !

Depends....if the circuit was designed around the -j 1370 capacitive reactance then the metal film will have the most impact on change.

Carbon comps (NOS) have a bad habit of absorbing moisture...I’m curious how the reactance would change after a good baking to drive out any moisture.

Just thoughts at 4AM...

Cecil
K5DL
> 
> 
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