Antennae extension

[Twister_Ken]

At the moment my AIS aerial sits on the pushpit. When the boat's in cruising config, the outboard is stowed on the pushpit right next to it. I believe that may be why, sometimes, I don't get an AIS signal from ships that are well with visual range - line of sight - until they are maybe two or three miles out.

I'm wondering whether to put the AIS aerial on a short mast, like these below from Glomex, not so much for extra range as to get it out of the shadow of the outboard. Masts are available in a range of lengths from 150mm to 2000mm.

Given that there's a robust mount that the current aerial is screwed to, how high does the panel reckon I can go before I'd need to add some bracing to the mast - a complication I'd like to avoid if poss.

Masts are available in stainless

or GRP.

Which do you reckon would be best?

 

[Pinnacle]

A metre?

 

[William_H]

Yes a metre above the top of the rail will make a huge difference to range. olewill

 

[nigelmercier]

Unless it's a stubby antenna, I doubt the outboard will make much difference. But an extension will obviously increase the range.

 

[Twister_Ken]

It is a stubby, Digital Yacht ANT200…

 

[Salty John]

That's a combined antenna and AIS engine - quite heavy compared to an antenna. Even 1m would be a strain on the rail mount bracket if it's the typical type with two clamping bolts - it will tend to try and rotate around the rail.
You could consider an extension pole on a deck stub at the base of the pushpit and then a brace to the top rail.
Whatever you do, it would be advantageous to get the antenna out of the shadow of the outboard.

 

[Twister_Ken]

You could consider an extension pole on a deck stub at the base of the pushpit and then a brace to the top rail.

I like it!