Hello Icom 706:
Thats the Commercial big boy stuff alright.
But the LMR-400 is the good stuff for sure, take it to the bank.
I wish I had a dime every time someone has e-mailed me having antenna problems, that are from bad Coax , or crimped coax connectors, or poorly soldered coax connectors.
The funny ones, are the ones that ask how much water is allowed in the coax, hehehehe the answer of course is none. The Coax Connectors are not water proof, you have to make them water proof. Using shrink sleeving, black tape, and Silicon RTV Rubber.
Using the RG8X coax will work but the question was, what is a good upgrade. And LMR-400 is a excellent upgrade Coax.
Again wishing I had a Dime for every time some has removed the RG58 or RG8X to install a better Coax. I use RG58 to tie up branches and trash. The RG8X I have a few jumpers made from it.
A good concern to a antenna installation, is that you don't want to have to do again, by installing the good stuff the first time around. Its cheaper and better that way. It makes good sense in that if your going throw any fire in the wire. Another good thing with the better coaxes, they sure last longer.
Jay in the Mojave
http://www.a1antennas.com