Combining Different Coax

[BocaIII]

Advice from Jammer is good
My only suggestion is rather than RG58 use rg8x lower loss at VHF frequency

[Sjoerd02]

I used Aircell 7 cable in 18 meter mast, excellent result! Much better then RG58. AIS range up-to 40NM from commercial ships.

[Jammer]

Originally Posted by BocaIII

Advice from Jammer is good
My only suggestion is rather than RG58 use rg8x lower loss at VHF frequency

The thing to watch with RG8X is that it's foam core and can be easily damaged by a combination of heat and tight bends. Bend it a little too tight or crank down the zip ties too much and you can have an installation that works great until it's in the hot sun and the foam loses its strength due to heat. Then the center conductor isn't in the center any more and possibly shorts out to the shield. 8X is ideal for experimenting and temporary installations where its low loss, light weight, and low cost are all advantages but I don't like to see it used for more critical installations.

[BocaIII]

Just avoid RG58 on vhf frequencies due to high loss