VHF aerial cable and connectors, quick beginners guide?

[DHV90]

Hi all,

Need to run a length of coax from where the cable exits the mast, in the saloon, to the new VHF by the companion way. Im totally new to Coax and connectors and there seems to be an awful lot of different model numbers for both cable and connectors.

Can anyone give me a basic explanation of what I need to use for a VHF and how best to go about it, which connectors to use etc.

Many thanks!

 

[MoodySabre]

I expect you are using RG58 cable. if you want htis to be removable then use two PL259 plugs (you can get solder on type or screw-on solderless) and a connector like this https://www.amazon.co.uk/PL259-Sock..._rd_t=40701&psc=1&refRID=EFA3C91M4KRZBJNBVAFF

If it is permanent then youtube will show you how to splice the coax.

 

[Martin_J]

and if you put one of those PL259 plugs on each end of the cable between the mast base and the companionway, and one on the end that appears (from the antenna) at the mast base, then you'll need an so239 double female adapter to make the joint at the mast base.

http://www.nevadaradio.co.uk/cables-leads-plugs/plugs-adaptors/nevada-uhf-060

 

[Martin_J]

Sorry MoodySabre - I'd not clicked on your link. I only saw the first few letters that mentioned PL259-So....

To the OP - PL259 is the usual plug and SO239 is the usual socket. Do get one to match the cable size. Some co-ax is thicker than others (depending on the type you buy).

 

[skipmac]

Not sure about over there, but in the states AMP brand connectors are the top of the line, dependable quality and only a bit more than the generic Chinese connectors.

If you are good with soldering then the soldered version of the PL-259 is my preference but it isn't the best if you aren't practiced in the art. Also takes a very hot soldering gun to do it right and not melt the insulation. I prefer one of the small butane torches (torch as in flame, not flashlight ).

If you don't have the tools and skills for the soldered version there are screw together ones that are supposed to work as well. Regardless of which version you use, before assemble slide a few inches of heat shrink onto the wire and shrink it over the end of the connector when done. If you use the female, double ended connector at the base of the mast for disconnect when pulling the mast you should heat shrink over that entire assembly to keep it dry in the bilge. Easy to cut off if you need to.

 

[Salty John]

Here's some information that may help:
http://www.saltyjohntheblog.com/2018/01/coax-cable-connectors.html

 

[Steve_N]

Here's some information that may help:
http://www.saltyjohntheblog.com/2018/01/coax-cable-connectors.html

Love it, thanks, particularly how they got named e.g. BNC and TNC!

 

[DHV90]

Excellent, thats really helpful thanks all. Is there any simple multimeter check to assess condition of the actual antenna and in-mast coax? Just so Ill know if I've done my bit right or not! Don't 100% trust the in mast wiring considering just about everything else on the boat that the PO touched.

 

[MoodySabre]

Excellent, thats really helpful thanks all. Is there any simple multimeter check to assess condition of the actual antenna and in-mast coax? Just so Ill know if I've done my bit right or not! Don't 100% trust the in mast wiring considering just about everything else on the boat that the PO touched.

Simple? Not my kind of simple. Try using the VHF - this is a proper occasion for the dreaded “ ..... radio check please”

 

[Daverw]

Excellent, thats really helpful thanks all. Is there any simple multimeter check to assess condition of the actual antenna and in-mast coax? Just so Ill know if I've done my bit right or not! Don't 100% trust the in mast wiring considering just about everything else on the boat that the PO touched.

Unfortunately no easy way to test without using an antenna analyser which cost about £250 or an SWR meter which will give you some idea

 

[Salty John]

A multimeter is only of use to tell you if you've fitted the PL259's correctly. Detached at both the radio and the antenna, you should see no circuit between centre pin and outer shell of the PL259. You then know you don't have a short - usually caused by a single strand of the centre conductor being snagged as you pushed it through the centre pin on the Pl259, and bent back to make contact with the body. Once you connect to the antenna you'll see either a dead short (antennas that are internally grounded as lightening defence - Metz, Shakespeare), or some specific resistance for other types of antenna.
If the cable run is good, the best check is then a radio check.

 

[john0740]

The usual problem is simply that the connectors won't fit through cable routes and so folks look to run co-ax cables and then add connectors.
To overcome this problem without the worry of poorly fitted connectors, consider the use of cable pre-terminated with FME connectors.

These connectors are little larger than the diameter of a RG8X cable and make running coax cables straightforward. FME-UHF adapters allow for equipment connections. Not as cheap as some RG58 and PL259s but avoids a lot of work and potential issues from poorly installed connectors.

Example pre-made FME cable (various lengths)
http://www.glomex.it/leisure/eng/accessorio-RA350-24FME.php

Example FME-UHF adapter https://uk.rs-online.com/web/p/rf-coaxial-adapters/1243270/

P.S. I have no connection with any supplier and personally usually crimp RF connectors (but I do have access to the necessary crimp tooling).

 

[Momac]

http://www.kcb.co.uk/shop2/contents/en-uk/d43.html
select custom made lead in the length you require with rg58 cable and connectors as required