[NJARC] Philco 37-650 RF Question

[Mbeeferman at cs.com]

Having done a little research in this area, I tend to agree with Jim.  A 
rating is a rating, and functional differences between a 1-watt carbon composition 
and 1-watt film resistor should not exist.  Problems at high frequencies come 
into play only with wirewound substitutions.  
I tend to believe that Bob's problem may have been in another area.
The problem with carbon composition resistors, especially NOS, is related to 
how critical a tolerance is required.  The process that creates carbon 
composition resistors leaves them under stress.  Over the years, this stress is 
eventually relieved (I won't go into the physical details) and the resistor can be 
left significantly out of tolerance.  As an experiment, randomly select 10 NOS 
carbons from your junk box that are greater than 20-30 years old and take 
some measurements...you might be surprised.
In any restoration project, I always`use the same philosophy...it might take 
some extra time, but it is surely worth it....
1.  Verify what you install and don't depend on the markings.
2.  Verify what you remove (unless the component is completely destroyed) and 
ensure it makes sense with regard to the circuit or the schematic.
3.  Don't make any more than 3 replacements without firing up the set to 
ensure that you're not introducing more problems than you're trying to fix.