[AMPS] Clipperton L amplifier

[Tom Rauch]

> >my guess was a sudden overload.  The event was so brief that there
> >was no damage to the outside of the resistor -- even though the
> >resistor element 
> > was almost burned out.  

The reflector has been down this road before. 

I have found hundreds or perhaps thousands of carbon composition 
resistors that behaved that way, even when used well bel0ow the 
ratings in dc or low-frequency AC circuits. Many others report the 
same.

That is why carbon resistors have fallen from favor in critical 
applications, especially when in hot environments.

> >>>>Were these amps that were measured while exhibiting intermittent
> >>>>vhf oscillation damaged in any way by the oscillation?
> >>>
> >>>the vhf suppressor-R was typically damaged.  The resistance
> >>>suddenly increased 2x - 4x.

This claim would only be valid if the resistor was measured 
immediately before failure and found perfect, that there was a 
confirmed VHF oscillation, and that when checked again 
immediately after the value changed.

One can not use an "it was off value, so it MUST have been a VHF 
parasitic" as proof of the cause of damage. Many things, including 
temperature and time, cause carbon resistors to go off value.


73, Tom W8JI
w8ji@contesting.com

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