[Amps] SWR increase on SB-220 input

[Pete Smith N4ZR]

I've been operating a lot of 18 MHz recently with my SB-220 set on 15 
meters, and I now notice that the input SWR on 15 is over 2:1, resulting 
in some exciter foldback and reduced output power.

I'm presuming that I may have partially fried one of the capacitors in 
the amp's input circuit by operating it this far off the intended band.  
Does that make sense?  If so, where would you look first?

-- 
73, Pete N4ZR
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