I have a glass ES with 2 Bob Archer com antenna, one in the baggage area fuselage side (SA-006), the other in the vert stab (SA-008).  The SA-008 in the vert stab uses RG58 lead in coax, the other uses the newer RG400. 

 

The problem is the SA-008 in the vert stab produces a weak signal as reported by the controllers.  If I switch the antenna between com1 & com2 the problem moves with the antenna.  This is not a new problem - it's been there since first flight.

 

Question for the antenna experts:  Could this problem be caused solely be the higher impedance RG58 coax or is it likely there are other problems?  This is a single piece of coax with not splices. 

 

I'm vacillating between installing an external antenna on the belly or just changing out the coax on the vert stab antenna.  I don't have an access panel in the vert stab but could install one if needed. 

 

Suggestions/advice appreciated. 

 

Leon Smith
Dry Creek Airpark
LNCE N63LS