Leon,

 

I have the same setup, same RG58, same antenna in my ES and it works fine.  I have no splices in my cable, just the connector at the radio.  I would check for possible kinks or damage to the cable or problems where the cable connects to the radio.  If you have any other connectors, check them.  Of course, if the problem is at the antenna things get complicated and I think I would just "cut the cord" and install a new external antenna.

 

I think an avionics shop can trace the problem for you too.  The RG400 vs. RG58 doesn't matter as much at VHF frequencies.

 

Mike Easley

Colorado Springs

Super ES