VHF aerial

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bromleybysea

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Following on from another thread, I used to have a continuous lead from the aerial at the top of the mast to the VHF set but when I lowered the mast this year for the first time in several years it was easiest to cut the aerial lead below decks. What's the best way of joining it up again, the main parameters are reliability and not complete confidence in soldering small components due to arthritic thumbs:(. Though if it's the only way I'll have a go. Second question, when I reassemble the aerial on the mast, can I test the aerial and lead as far as it emerges from the bottom of the mast before it is stepped? Thanks.
 
Best way:Socket on deck

To connect below deck PL259 on each end of the cable and a coupling like this to join them together. Unfortunately soldering would be necessary on the plugs but the centre pins that need soldering are not that small.

Adapters may or may not be required for the plug to fit the size of cable.

Testing before stepping: connect to VHF but that requires plug to be in place, which will then need to be removed again.
 
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What our boat has in an N type socket set into the cabin roof, and an N type plug on the end of the coax from the mast, with a waterproof boot over it.

To unstep the mast, pull up the boot, unplug the N plug, and put a boot over the N socket to stop water getting in.

N type plug and socket used as these are infinitely better quality than pl259/so239 and actually built with waterproofing washers at the cable entry and mating faces so they are splash proof as they are, but still need a boot over the plug to make them totally waterproof.
 
Best is to make any join inside the boat. If the join is by two PL259's and a barrel connector (my preferred choice) it is best to take the cable through the deck via a deck gland which will accept the cable with PL259 connected. (This assumes a deck stepped mast, of course). Index Marine has a range of deck glands in plastic or metal - we only stock the aluminium version.
When you've fitted the PL259's you can test to be sure they aren't shorted with a multimeter across the centre pin and outer shell. To do this the antenna and radio must be disconnected or you'll show a short anyway.
If you can bring both ends of the cable together you can also check for continuity between centre pin and centre pin, and outer shell and outer shell. This is usually impossible if the cable is already in the mast - unless you have a multimeter with 25' leads!!
Note that the PL259 + barrel connector joint is quite bulky at, typically, 9cm long by 2cm diameter.
 
Salty John said:
Best is to make any join inside the boat. If the join is by two PL259's and a barrel connector (my preferred choice) it is best to take the cable through the deck via a deck gland which will accept the cable with PL259 connected. (This assumes a deck stepped mast, of course). Index Marine has a range of deck glands in plastic or metal - we only stock the aluminium version.
When you've fitted the PL259's you can test to be sure they aren't shorted with a multimeter across the centre pin and outer shell. To do this the antenna and radio must be disconnected or you'll show a short anyway.
If you can bring both ends of the cable together you can also check for continuity between centre pin and centre pin, and outer shell and outer shell. This is usually impossible if the cable is already in the mast - unless you have a multimeter with 25' leads!!
Note that the PL259 + barrel connector joint is quite bulky at, typically, 9cm long by 2cm diameter.
Click to expand...

This is exactly what I have just done after renewing the aerial, cable etc. I found the deck mounted connection a real pain as water WILL get in and corrode the wire(in my opinion anyway) The only snag is that in my case the inside joint is behind the headlining so needs lifting to connect the PL259's together. My VHF should now work! A new aerial, good cable, deck gland etc is not cheap - in my case it cost more than a modern cheapo DSC set.
 
vyv_cox said:
Me too. I have never bothered to solder the PL259s and indeed there are some versions that specifically say that soldering is not necessary.
Click to expand...
If you don't have the non solder type then you MUST solder. Two reasons: You won't transmit efficiently or at all, and you may just blow the output stage on the VHF because of no load.
 
ostell said:
If you don't have the non solder type then you MUST solder. Two reasons: You won't transmit efficiently or at all, and you may just blow the output stage on the VHF because of no load.
Click to expand...

Well, it's probably something like 15 years since I last bothered to solder one. So long as you make sure the central wire is making good contact there is no problem. On several occasions I have been advised by other boats that my transmissions are unusually strong and I have never damaged either of the VHF sets I have owned.
 
Can somebody telly mw where you can buy the connectors? I'm struggling with BNC and was thinking of the PL259 route, but can't find anywhere. Guess my ideal would be to have a F-F inline adapter and Male plugs on each line.

PL259 guides above very helpful, I'm suffering with BNC. Thoughts Chaps?
 
Mast Aerial coax to a coax already plumbed into rear of VHF.

Straight Coax to Coax join... but I'm failing badly... Suspect now the aerial may have got dingged worse than I'd previously thought, in the yard last winter :(
 
I have to say it, PL259's are horrible connectors.

Persevere with the BNC's. What issue are you having with them?

A good BNC plug and in line BNC socket will do what you want. If you are struggling, you either have the ****py twist on sort, or the wrong ones for your cable.

At the base of my mast as a "through deck" fitting I have an N type plug and socket. they are good connectors also, much like larger BNC plugs (but with a scwer locking ring instead)

Is this a permenant joint? if so you need a good wrap of self amalgamating tape.
 
I join mine below decks with crimped on M & F BNC connectors (50Ω). If you're willing to invest £20 in a crimping tool, they're easy to use - and you can either sell them again on ebay or make yourself popular with other club members by lending them out. It's surprising how many people suddenly realised I could make extender cables or shorten their depth sounder cables, etc. Something they had been putting off for the last decade or so.

Rob.
 
I'll check the cable dia/type tonight, so I can order the right bits.

Connection is under the cabin ceiling, in the heads and a am running out of wire to cut back on attempts! right now I have twised the cores & screens together just to see if the aerial picked up anything - it didnt. I suspect the ding'd mast aerial may now be busted, so will go up an change that next weekend.

Do you know of any useful guide on how to do BNC connections? I am clearly missing a step, either reassembling the connector or fitting the wire to it.
 
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