VHF Antenna fail

[footloose]

Looking to replace antenna which broke.

Relocating it to radar arch which is about 10 foot above water line. Do I still need a 6 footer when off shore or can I go with smaller folding unit for the few low bridges I have to sneak under?

We mostly dive, stay in view of shore except for occasional Bahama runs and some Key west tripswhere we cut the "corner".

Suggestions and why?

Thanks!

Foot

 

[Radioactive]

longer antennas are desirable for two reasons:

greater height above water

higher gain

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In this case, your antenna is likely "high enough" for any size antenna. The mounting height is high enough to resolve much of the "line of sight"issues.

The second reason is the one why you need to make a decision. Antenna gain is another way of expressing "effective radiated power". By compressing the radiation pattern to a narrower vertical radiation angle, the effective signal power is higher with higher gain antennas.

SO, if you are in a congested area, where you might have many unsophisticated radio users making "undirected radio checks", you will have a better chance of having a more powerful signal and carry on communication when using a higher gain antenna ( vs a shorter, unity gain antenna ).

Having a higher gain antenna is a very nice feature, but if the constant raising/lowering of the "big stick" tends to cause you to leave the antenna non-deployed, then the shorter antenna, always deployed, is the best choice.

 

[chriscraft67]

You might find the SS-2 marine antenna made by GAM Electronics to be a good trade off. The stainless antenna is about 35 inches long. The antenna and coil use an adapter to mount on a marine antenna extension. In your case a 3 or 4 ft. extension would probably work. The resulting extension plus antenna would be very light and easy to lower if need be.

These are very high quality, hand-made, all stainless antennas that I have used for years for both VHF marine and the 2-meter amateur band on my boat and I almost always get very good signal reports even in a seaway.

 

[rbmitchell]

I would go with a three foot, base loaded whip. If you damage that on a low bridge, you'll have taken out your radar also.