VHF Radio Antenna

[helliconia]

I'm looking at taking my little 4.75M tub a bit offshore (definitely not WIDE though haha).

I have been looking at some VHF radios but need to know what size antenna should I be matching it to. Most of the radios seem to be of the 1W/25W variety. I can't see myself more 5 or 10kms offshore.

I just want to be sure I have the necessary range back to shore if I should need help.

[Evets]

Empty,

Go for the longest antenna you can get and mount it as high as you can. The higher the antenna the better the range.

Evets

[Fisherman36]

Empty,

Go for the longest antenna you can get and mount it as high as you can. The higher the antenna the better the range.

Evets

Agree, get the longest that you can (within reason). The higher and longer it is the better, but make sure the base you get for it can support it. A lot of antennas come with bases. 5 or 6 foot long should be ok.

[Testlab]

Make sure it's a VHF marine antenna. Sounds silly but unless you know what you are looking for it is quite easy to mistake a 27MHz aerial for a VHF. Don't forget you need a marine radio operators certificate for VHF and the course will teach you a lot of useful info.

[helliconia]

I've been looking at the course too. I'm just getting an idea on the cost of upgrading some bits for close offshore trips.

The will get the final say based on the budget

Is there anything "wrong" with the low end VHF radios, like the GME GX600 in the $250 price range?

[EDIT] Damned typos!

Edited October 19, 2011 by EmptyHooks

[Testlab]

The lower priced radios in Australia usually don't have DSC, which I think is another case of Australia being left behind when there is no good reason to be. All small craft VHF radios nearly perform the same since the installation limits performance more than the radio performance itself.

Although everyone focusses on transmit performance it is equally important to have good receive ability too. With a decent aerial in good condition, aerial cable that isn't water damaged and clean connections the receive performance will be good. Any problems with any of these items will degrade/reduce both receive and transmit performance.

If the equipment is in good order the next biggest killer of receive performance is electromagnetic interference from sounders, plotters, digital engine instruments, nmea2000 networks, engine ignition or computer interference, etc. Unlike a 27MHz radio where you hear the interference as repetitive static a VHF will simply have a higher noise floor in which faint signals simply disappear.

Most sounders and plotters come with clip on ferrite suppressors that go around cables. These ferrites don't affect the performance of the plotter or sounder but do have a big impact on radio reception. Even with them in place it is sometimes prudent to switch off the sounder and plotter if you need best possible radio reception. Route your aerial cable and power wires for the radio away from the other wiring if possible.

Hope this helps.

Edited October 19, 2011 by Testlab

[pure spirit]

I've been looking at the course too. I'm just getting an idea on the cost of upgrading some bits for close offshore trips.

The will get the final say based on the budget

Is there anything "wrong" with the low end VHF radios, like the GME GX600 in the $250 price range?

[EDIT] Damned typos!

Mate i have the basic GME think it's the 600, with a foot long antenna, on my cuddy cabin so it's about 2m from the water surface... I believed that I would need to get a bigger antenna (like everyone is saying)but when i realise i could hear the game boats (east of browns) talking from my home on the upper northshore I figured i'd save my money.

I have no dramas (sometime not the best but i can always communicate) checking in the marine rescue sydney from browns.

Bottom line if i needed to buy a new antenna I'd get a longer one but the way the short one is set it works just get it up high.