Can I hide a VHF antenna inside an Ensign flag pole

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picardy

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I am looking to install a fixed mount VHF on a wooden motor launch and am keen that the antenna is hidden. My options are a stub antenna in the forward or aft locker or trying to disguise the antenna inside the ensign flag pole. This would involve making a thicker pole, splitting it to install the 600-700mm antenna and then gluing it back together with a discrete wire coming out of the bottom.

My question is has this ever been attempted and does VHF transmit and receive through timber?

Many thanks
 
Dry clean timber I would not expect to be too much of an issue, the low height would be a much bigger issue I would have thought
 
IMHO Anything in the way of an antennae will degrade the signal, wood and plastic probably less than metal. I would be inclined to look at a solid metal antennae, make it look like wood and stick an ensign on top.

I am an ex theatre sound engineer who used to use radio mics before the advent of diversity receivers, aerial distribution systems and directional receiver aerials.
 
picardy said:
I am looking to install a fixed mount VHF on a wooden motor launch and am keen that the antenna is hidden. My options are a stub antenna in the forward or aft locker or trying to disguise the antenna inside the ensign flag pole. This would involve making a thicker pole, splitting it to install the 600-700mm antenna and then gluing it back together with a discrete wire coming out of the bottom.

My question is has this ever been attempted and does VHF transmit and receive through timber?

Many thanks
Click to expand...
Certainly going to be better than a stubby aerial inside a locker but do try to mount it vertically for best performance.

www.solocoastalsailing.co.uk
 
Sea-Fever said:
Seeing as VHF operates around the 160 Mhz freqs (I think) the corresponding loss would be small.
Click to expand...

And since the line-of-sight distance will be limited from a (presumably deck-level) ensign staff, transmission power probably isn't the limiting factor in any case.

Pete
 
Why not just have a demountable aerial that can be mounted in the normal way when the boat is at sea and needs to have useable radio communication, and demounted when the boat is taking part in whatever Concourse d'Elegance or "parade of sail" she might take part in, where the 'modern' addition of an aerial might take away from her appearance.
 
I think your best bet is to use a fibreglass fishing rod as the ensign pole. So easy to stuff the antenna up the pole. The simplest form is to use a piece of coax cable where you expose 17 inches of the inner. Then you need a ground plane of 17 inches long going from the top of the outer (bottom of the 17inch exposed centre ) downwards. I have used outer sheath from 10mm coax. It has to be outside the outer insulation of the RG58 coax and insulated from every thing else. This type of antenna can then be poked up your pole as high as possible. Ok use wooden pole with the centre routed out in a similar manner if you insist on wood pole. ol'will
 
The effect of the flag and flag halyard close to the aerial when they are wet would keep a radio engineer busy for a while.
Personally I'd use a thin stainless whip aerial on top of the staff.
It wouldn't be hidden, but wouldn't be very visible either.
 
I was an RF engineer many years ago.
At VHF frequencies the attenuation will not be noticeable for 99.9% of all practical purposes. So long as your angle from the vertical isn’t too much, you won’t notice that either, but try to keep it only a few degrees from straight up and down.
Will’s suggestion will work, but if you can fit a commercially made antenna into your wooden pole you will get a slight improvement. (Commercial antennas are often 5/8 wavelength and show a flatter squeezed radiation pattern , and hence ‘gain’ over a quarter wave vertical)

If we were talking microwave frequencies it would be a different story.
 
Hi all thanks so much for the excellent advice. My preference is to try to conceal it within the wooden flag staff if possible - can anyone suggest a suitable antenna (ie make and model or a weblink) that would be suited to this as there are so many different types its a job to know where to start!

Any if possible, a recommended antenna option for the top of the flag pole if I went for that instead.

Many thanks
 
For my AIS I am using a home made dipole from co-ax as described on here many times. It's pushed up inside a piece of white conduit to give it mechanical stiffness for mounting. It wouldn't be strong enough fo a flag pole but it should be easy to find a length of plastic tube or fishing rod that will do the job and change it. Great idea to have it inside the flagpole. Another little job for the list.
 
Most manufactured antennas will have a fairly chunky base, either for ballast or to fit on a 1" diameter mount.

You could use something like the VTronix HA156C on top of the staff. Only 6" long.

Or if range is not that critical, why not just use a handheld? They can all be recharged from a 12V supply. You can use an adapter to connect to taller/higher temporary antenna if needed.
 
I think you should have the antenna motorised, so that it appears and extends from the top of the flagstaff. For additional effect have a small rotating parabolic reflector at the top, going "beep" with every revolution.

Maybe I have been watching too many Bond films.
 
JumbleDuck said:
I think you should have the antenna motorised, so that it appears and extends from the top of the flagstaff. For additional effect have a small rotating parabolic reflector at the top, going "beep" with every revolution.

Maybe I have been watching too many Bond films.
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Maybe not so daft - How would one of these work on transmission?

https://www.amazon.co.uk/Autoleads-...4TW84OO/ref=pd_lpo_1?pd_rd_i=B004TW84OO&psc=1

Hide it in a fake nav light or something. I'm sure it wouldn't be ideal, but in practice, and for line of sight distances a metre or two from the sea, would anyone or anything notice?
 
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