Do VHF antennas go bad?

[follysurf]

Hi all,

This may be a stupid question, but I am about to pull new coax in the mast while it is down and am wondering if I should replace the antenna as well to avoid a problem later on. The current coax has deteriorated and been repaired several times. When everything was connected the VHF worked so the antenna is good although it does have mild corrosion.

Should I assume that everything will work well and not waste my money on a new antenna?

Thank you.

[btrayfors]

Maybe, but it would be better to replace the antenna while the mast is down. If you're seeing corrosion on the antenna, particularly if it's a coil-type like a Metz, then replace it. VHF antennas are very cheap insurance and, after all, the VHF is arguably the most important safety thing on the boat.

Coax repaired? Why? It should never be necessary to "repair" coax, unless it's been improperly installed.

If you can, use RG-213, 214, or LMR-400 coax for the transmission line, especially if the run is 50' or more. Alternatively, if you can't fit the larger coax then use RG-8X and install it so it's protected and you won't ever have to repair it.

Bill

[olson34]

I replaced a 15 year old Metz-type antenna and the run of coax to it. The antenna came off in pieces and I knew from research that the old coax had been superseded in the market by better product.
In the whole scheme of things (a re-rig) it was cheap. We pulled new tinned wired thru and replaced the UV-damaged anchor, steaming and foredeck lights, too.

Far easier (and a lot less labor intensive - i.e. costly) to do this work all at once, with the spar horizontal.

Mind you, all this stuff worked to some extent before the replacement/upgrade.
It has a useful-life-span, like all the systems parts on a boat.


You may be pleasantly surprised at the increase in range when you then make and receive calls on your VHF.

Sidebar: You did not ask, but since it's winter and unsolicited advice is free on the internet, take your VHF radio in for a free check up in the off season... I would imagine that most reputable marine electronics shops will do a no-cost bench check for you.......
We have an excellent shop here that's been doing this for decades. They keep handing back my '88 Furuno radio and telling me to keep on using it - no freq. drift and up to rated power output).

(I asked if they were ever tempted to say it was "showing a diminished thermothrockle output" and then sell me a new one. They laugh and say they do not do business that way! )

One of these days I will probably get a new fancy DSC radio, but for now, it's a "feature" that I do not need.

Best,

LB in PDX

[MarkSF]

Definitely worth replacing it. Here's the one I just used :

Shakespeare Antenna Specifications: Shakespeare Squatty Body® 5215-AIS VHF Marine Band

About $60 online.

I spent a lot of time tracking down an interference / bad reception problem. In the end the fix was to replace the RG8X cable between the radio and the base of the mast. (there's a union at the mast base and the thick stuff goes up the mast). So if you're replacing the mast cable and the antenna, I'd go the whole way and fit new cable all the way to the radio, all with quality gold-plated solderable Shakespeare connectors. I trust the Shakespeare RG8X too.

[smurphny]

Have had a lot of these on both power and sail and have never had one go bad except for plastic mount-type. Actually use an older one on mast because it's obviously made a lot better than the new one I keep for a spare.

[follysurf]

Thanks for the responses. My original thought was to go ahead and replace so I will stick with that plan. I agree that it is an inexpensive piece in the grand scheme of things. I am also pulling tinned electrical wire and replacing the anchor, steeming and foredeck light. I would rather do everything right and know that all is good when I step the mast.

As for the repaired coax... the connections between the mast base and deck entry had been repaired several times. My guess is that the wire got kicked around a bit by the previous owner.

I was planning on using RG-8X but will look into the others you mentioned.

[neverknow]

I was a communication electronic tech in the navy yrs ago. Keeping the radios on the ship going was my job.

The antennas do not actually ever "go bad" however just like everything they are susceptible to water damage. If yours is sealed and has no signs of corrosion it will be fine.

All that is inside of them is a wire of the proper wave length, keep it dry and it will last forever.

[ccriders]

One last thing,
It is very important that the coax is attached to the masthead inside the mast with a hanger, that there is an "O" ring seal where the coax leaves the mast, that there is a drip loop in the coax before it attaches to the antenna base and that the attaching connector is weather proofed. I use shrink wrap for the weather proofing but left the bottom end of the shrink wrap "unshrunk" so as not to trap moisture in the connector but protect it from rain, spray and condensation.
With anything electronic, you will have more problems with mechanical parts than electronic. Hence the care taken in installation will pay dividends.
John

[follysurf]

Olson34: From looking at the current VHF, I'm pretty sure it is original to the boat, 1972! It worked prior to the coax seperating so I am planning on continuing to use it although I know even the cheap ones are probably better. I am thinking of upgrading but it is not as pressing as other repairs ( I am running new coax from the deck entry to the radio). Maybe I will have it tested just for fun.

[MarkSF]

Do a radio check when it's all done, reception and transmission.

I don't think analogue electronics have changed that much since 1972. It's the extra digital features that have moved on.

If you do ever upgrade I just installed the Standard Horizon GX2150 with DSC and AIS. It has a really good 80db receiver too. Quite impressed.