[Elecraft] KPA500 Issues

[Kent Tiburski]

Hi,

  I have a KPA500 amp and have some issues with it.  I ran on my Cushraft R-8 vertical with fault (SWR) problems.  I went to use it on the VHF contest with my meager 3 element yagi and it faults out?  Hunhh?  Checked the VSWR with a meter and my antenna analyzer and it shows a 1.2 to 1 ratio.  OK I thought there was feedback so I put a bunch of ferrite cores and even wrapped 8 turns on the coax (balun) to no avail.  What gives?  This was mainly on 6 meters but to some extent on other bands also.  Checked VSWR with a meter on radio (FLEX 5000A).  I think it's in KPA500 circuit.  Any ideas?  I'm a newbie here so not familiar with what's been discussed. Thanks.  

73, Kent, K6FQ