Making a DIY emergency VHF aerial

[JohnTH]

Just goes to show how black the art of aerial design is. I have had endless success with dipole aerials. They are so simple and easy to make. As with most things though, whatever works for you is the important thing.

It is my opinion that, if you have your emergency aerial fitted and ready for instant use, it will never be needed.

MOBOS ??

Remember KISS.

73s de
Johnth

 

[jetwake]

A slim Jim coiled in a locker would maake a better emergency VHF antenna. Could be hoisted from a halyard if required. easy to maake from 300 ohm ribbin.

David

http://www.m0ukd.com/Calculators/Slim_Jim/index.php

http://www.hamuniverse.com/m0uxbslimjimnotes.html

http://www.n9tax.com/Slim Jim Info.html

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220477854803

 

[JohnTH]

Fantastic idea jetwake. A slimjim should work well.

Only problem that I can see is the halyard. How is the aerial deployed if the mast is down?

73s de
Johnth

 

[john_morris_uk]

Fantastic idea jetwake. A slimjim should work well.

Only problem that I can see is the halyard. How is the aerial deployed if the mast is down?

73s de
Johnth

And there was me trying to keep it simple! The slim jim is a fine idea, but not many will remember the dimensions to actually make one in an emergency. Stripping coax to make a dipole that's about 3' long will definitely work - and as I said before, "Tape it to the boat hook and hold it up!"

A slim jim made from 200 ohm ribbon would be easy to stow. Personally I have an old rubber duck type antenna on a length of coax in our Flares Box as the emergency antenna. I made it over twenty years ago and its never been used.

 

[JohnTH]

KISS is good for me boys.

My emergency aerial is part of my flag pole that is fixed to the transom. How simple is that?

73s de

Johnth

 

[CET1]

I use a slim jim antenna for our AIS reciever. Cost less than a fiver to make and has worked well. It also works for our VHF radio.

 

[Martin_J]

Bluechip..

And if you have time on your hands and want to play even more with the aerial cable.. How's about trying a 5 or 9 element co-linear aerial..

Description here on how to construct... http://web.arundale.co.uk/docs/ais/aerial.html

It's an interesting read to say the least!

 

[fisherman]

Too complex for the OPs purpose, but I have two slim Jims in the garden attached to an Icom DSC and an old Icom handheld. Made from 8mm copper tube tacked to a batten and shoved up a plastic pipe. I can receive Ushant traffic in high pressure conditions.

 

[rob2]

Another vote for the Slim Jim! I made a few for friends from ribbon cable and cased them in oval conduit (it's a good close fit). Sealed the ends with mastic and put a hanging loop on one end. It seemed to give better performance hanging from the spreaders than the masthead antenna! If I remember correctly there is a correction factor of 0.9 applied to the calculations ad the VSWR was around 1.2.

Rob.