Mobile Mount Coax Extention Cable

This is the cable extension, RG-58C, from the mobile antenna mount. The mount uses RG-316 because it’s thin enough to fit along the tail light assembly. The other mount I looked at used RG-58, which would have required squeezing it to fit along the side of the tail light assembly. That would have likely screwed up the cable impedance resulting in an elevated SWR, which I didn't want. So, I stayed with the thinner RG-316 and a longer length even if it was higher loss. Sometimes you don't have much choice. 

I finally got the adapters I wanted and swapped out the RG-58C for a 10 foot section of RG8X mini. The RG8X mini has about half the losses of the RG-58C extension cable. It's also a bit fatter cable too. The photo shows the original cable installation.

https://diamondantenna.net/c110.html

https://fieldcomponents.com/mini-uhf-coaxial-Connectors.html