Chris,

 

RG 58 and RG 400 have different diameters and need different BNC connectors.  I've always thought it was interesting that A/S sells both cables but only the RG 58 BNC connectors.

 

Just a comment, I bet us builders aren't really making perfect BNC crimps and even though we use the "good" cable, we may not be building optimum antenna cables.  If you read the specs on Amphenol, for example, the tolerances on the stripping are very small.

 

It appears that the frequency is a large factor in signal loss.  Low frequencies like com and nav are not as critical as transponders and GPS antennas.  My GPS antenna cable is less than a foot.  My transponder cable is RG 58 and I had a significant signal loss when I got my initial transponder check.  I have no in-line connectors in my antenna cables.  When I mounted my com antenna in the tail, I dealt with a giant coil of cable until I cut it to length and attached it to the radio, same with the nav cable coming out of the wing.

 

Mike Easley