Originally Posted by ashbypower
Problem with that is that is is effectivley 2 connections and as a rule of thumb a connetion can loose 1db and affect VSWR if not done properly!!
Well it is effectively exactly the same as what the antenna was supplied with (just that the thread on the supplied connector was not long enough) so I dont anticipate any difference in performance compared to the way it was supplied which was with a standard SO239/SO239 double ended connector.
Anyway the job is now done. What I did, for anybody else in the same situation, was:
1) Sourced an approx 2 inch long SO239 fully threaded bulkhead connector to replace the double ended SO239 that was supplied, so it would screw well into the base rather than just 2 or 3 threads. I screwed it in about 8-10 threads I think.
2) Chopped the funny Raider plug off and fitted a standard PL259 onto the end of the original VTronix coax (which was standard RG58 when I looked)
3) Cleaned upper and lower surfaces of the A frame mounting plate then applied a generous bead of sealant around the top of the hole and around where the connector goes into the antenna base, squidged the antenna down onto the hole which squeezed some sealant through the hole in the A frame and around the nut on the bottom - tightened the nut and then put a layer of sealant from the A frame mount covering over the nut and onto the threads so there should be no chance of water ingress into the bottom of the antenna.
4) Fitted the PL259 onto the bottom of the antenna, and then wrapped it all up with Bandit self amalgamating tape right down over the plug and onto the coax
5) to finish it off I smeared another good layer of the sealant over the top of the tape so the whole lot is continuously sealed right from the A frame down over the outside of the plug body and onto the coax
Should be pretty much submersible now. The sealant I used was something called Stixall which is a flexible clear adhesive sealant, it doesn't have the vinegar smell so I don't think it is based on acetic acid.
I tested it and it works well, radio check back to SWMBO's house had perfect audio (4 miles approx, but with a fairly big hill in the way) and listening to other traffic the signal strength is miles better. There was definitely a problem with the Vtronix, not sure what was wrong but it wasn't working properly and this is miles better
Time will tell if it lasts (the stainless mast is fairly stiff) but presumably the USCG give them a fairly hard time so hopefully it will be OK.