[ICOM] IC-718 that dies on 30m, revives, dies again

[N4ch at aol.com]

Hello John,
 
Good luck with the Icom.........if it seems 100% OK all of the  time with a 
dummy load, then my guess would be an RF feedback issue (and maybe  just 
connecting a good ground to the chassis of the radio would fix  that).   The 
SWR on your antenna suddenly jumping sky-high is probably  caused by either a 
bad antenna/coax connection (causing a high SWR on 10  MHz) OR the PA might 
be "taking off" on some instability (on some far-removed  frequency from 30 
meters).......this would cause the SWR meter to read  high.   This could 
easily be caused by RF in the shack getting into  the radio itself.   Hope U 
find the problem.
 
73, Herman, N4CH.