You certainly don't want just any old coax. You for sure don't want any type of "hard line" run up the mast as the flexing will break the center conductor or outer conductor.
You want to have a stranded cable such as RG8 type. Also don't use any type of "foam" dielectric type cable on a boat as the center conductor will migrate to the shield and short the cable especially at places where the cable bends. Polyethylene center insulator is best for this application. Even though foam has slightly lower loss, the low loss doesn't do you any good if the cable fails. Inside a sailboat mast there is no way to secure the cable and it will flop around inside the mast. Lots of stress on the cable. As a side note, there should be NO solid conductor wires used on any boat. Only stranded wires due to the constant movement and related stress. 73 Gary K4FMX _____ From: Repeater-Builder@yahoogroups.com [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Vernon Densler Sent: Tuesday, November 24, 2009 11:18 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Best coax for marine use 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
