>Rich says:
>
> > However, when R-sup fails on 15m, 20m, 40m or 80m,
> >there is seemingly no way that enough fundamental potential could be
> >developed across L-sup to damage R-sup.
>
>Not so sure about 15, though.
? good point
>However, this argument assumes that the
>ambient temperature of the environment in which that resistor sits is low
>enough that the resistor still has dissipation capability available
>sufficient for the reduced dissipation in it resulting from the lower RF
>voltage across it, on lower frequency bands. For example, if the dissipation
>on 10 metres is say, 10 watts, then it will be 2.5 watts on 20.
? agreed.
>If the
>resistor has to be derated because the ambient is 80 deg C, then even the
>lower dissipation on the lower bands may well be enough to 'cook' it.
? the R-sups in the 922 receive cool forced air and they are virtually
HF-shorted by silver straps. Does it seem likely that lower-band RF
could damage these resistors?
>
- cheers, Peter
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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