Looking at the list below, you can see that the 1/4 and 1/2 Superflex Heliax have a very modest loss at VHF frequencies. I would use the 1/4 superflex. It is very accomodating to bends, although I know of no coax that is completly salt water-salt air resistant. I think that part of your pre-departure check, would be to examine the exposed pieces of feedline for any knicks or degeneration. Oh yeah, get the highest gain antenna you can get!
*Cable Type* *29 MHz* *52 MHz* *146 MHz* *222 MHz* *440 MHz* *900 MHz* *1200 MHz* RG-8, RG-213, or RG-214 .90 1.3 2.2 2.8 4.3 7.7 9.3 RG-142/B or RG-400 1.9 2.7 4.4 5.8 8.6 12.6 15.2 RG-223 1.9 2.8 4.5 6.2 9.1 13.9 16.8 Belden 9913, Times 9086 .52 .91 1.5 1.9 2.9 4.2 5.1 1/4” SuperFlex Heliax .93 1.3 2.2 2.7 3.9 5.7 6.9 1/2” SuperFlex Heliax .54 .74 1.3 1.6 2.3 3.4 4.1 3/8” Foam Heliax .54 .77 1.3 1.6 2.3 3.3 4.0 1/2” Foam Heliax .35 .53 .88 1.1 1.6 2.3 2.8 7/8” Foam Heliax .18 .26 .44 .58 .83 1.3 1.6 1 1/4” Foam Heliax .14 .20 .33 .42 .60 .92 1.1 1 5/8” Foam Heliax .11 .16 .27 .35 .51 .79 .94 On Tue, Nov 24, 2009 at 8:17 AM, Vernon Densler <m...@highwayusa.com> wrote: > > > I have been in a big discussion with the guys on my boat list about the > right coax for running up the mast for VHF marine radio. > > > > Keeping in mind that we are talking about a 70’ or so run going up the > center of an aluminum mast, in a salt water environment, and the radio is > limited to 25 watts. > > Also keep in mind that when off shore this is a life line and the best > possible send and receive is needed in an emergency situation. > > > > So given the criteria what is the best possible coax to use knowing that > thickness matters and bend radiuses may be tight? Others on the list are > saying “just grab any old 8X type cable and you will be fine”. I say use > something with very low loss and suggested small heliax. > > > > Any suggestions? > > > > Vern > > s/v Nirvelli > > KI4ONW > > >
