Most caravans, it appears, are fitted with a short flexible whip antenna for their radios, usually roof mounted, these antennas are very poor performers at both AM and FM frequencies.
I considered replacing the one on my van with a better antenna but decided the work involved was too much.
Instead I've constructed an "add on" antenna extender, it is very simple and consists of a plastic tube, adhesive tape, a piece of galvanised wire and 10m or more (20m is good) of electrical wire.
The plastic tube should be about 150mm long by up to 20mm diameter. Almost anything will do but it must not contain carbon, to check this put the plastic tube and a glass of water into the microwave and set it to high for 30 seconds, if the tube warms up at all discard it and try something else.
Pick a point about 1.5m from one end of the electrical wire and starting here wrap the electrical wire tightly and with very close turns about 15 times around the plastic tube - do not overlap any turns. Fix it firmly in place with the adhesive tape.
The wire may be of any type of even different types joined together, the longer the better.
The tube should now have about 1.5m of wire at one end and, if you used 20m, about 18.5m at the other end.
Next bend the galvanised wire and tape it to either end of the tube, see photograph. This is simply a holding loop.
Now the fun part :)
Using a fishing rod or long stick with a hook lower the tube over the antenna on the caravan roof - this is not as bad as it sounds and usually takes me no more than a minute or two.
Finally: leave the short (1.5m) piece of electrical wire where it happened to land but take the long piece out to its full extent and tie it off as high as possible to a tree or the like. It doesn't matter if the wire goes through branches or round corners it will still work.
What happens radio wise is the wire acts as a radio antenna and the coils on the plastic tube act as a transformer and couple the signal picked up by the wire into the original caravan antenna. It works well.
Mine uses 20m of wire and turns totally unreadable stations into easily readable ones and poor stations into good ones. I guess that it adds about 6 'S' points if that means anything to you.
This device could also be used with a car antenna.
If you make one please let us know how it works for you.
Mike this interests me as I have very poor radio reception in NSW highlands - should the cable be insulated or would plain copper (Earth) strand be best? - what size wire/strand would be best?
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Possum; AKA:- Ali El-Aziz Mohamed Gundawiathan
Sent from my imperial66 typewriter using carrier pigeon, message sticks and smoke signals.
The windings on the plastic tube *must* be insulated but otherwise the rest of the wire may be anything from fence wire upwards. Copper wire works best (well... gold really :) ) but anything will do. This is a bit on the light side but will work well:
Thanks Mike - Yes I have some rolls of 13 x 0.12 so I'll give it a go.
Di Pole requires too much input on radio frequency/s - I attempted one a few year ago but it wasn't very good. On our block radio is patchy at best - No car radios work - Although we are at 800 meters elevation (Abercrombie headwaters) there are too many higher mountains all around us -
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Possum; AKA:- Ali El-Aziz Mohamed Gundawiathan
Sent from my imperial66 typewriter using carrier pigeon, message sticks and smoke signals.
I've been doing similar for years, a roll of wire from Jaycar, attach the end to antenna, I use an alligator clip, then run the wire out as far as possible and throw the roll over a tree limb or similar, drags in lots of previously unreadable stations.
Just take care I don't run it where a passer by can garrote themselves, normally not a problem as we normally free camp in remote area's as no one else around.
Santa wrote:I've been doing similar for years, a roll of wire from Jaycar, attach the end to antenna, I use an alligator clip
Most caravan antennas seem to be short (300mm) whips with a rubberised coating so the alligator clip won't be able to make a direct electrical connection, it will still work but not too well.
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"I beseech you in the bowels of Christ think it possible you may be mistaken"
Oliver Cromwell, 3rd August 1650 - in a letter to the General Assembly of the Kirk of Scotland
Santa wrote:I've been doing similar for years, a roll of wire from Jaycar, attach the end to antenna, I use an alligator clip
Most caravan antennas seem to be short (300mm) whips with a rubberised coating so the alligator clip won't be able to make a direct electrical connection, it will still work but not too well.
Your right, ours is a short rubber deal, pretty ordinary.
Will save your recipe and make one up before our next trip, appreciate the info, poor AM reception is always a problem in remote area's.
Jeez Mike, that's a bit sophisticated . Using a coil former and tape, etc. I use about 25 metres of wire with an alligator clip on one end. Connect the clip ( lower end of the coil ) to a bit of the van frame, wrap about 15 turns around the rubber ducky and secure the top of the coil with a knot and sling the rest in a tree.
I'm a big fan of the "wire in a tree" type of antenna. Easily transported, light and compact and easily erected. All that's needed is a small, home brew Z-match a counterpoise of about the right length and I'm on the air...
Back to the original subject, make the "tree end" as long as practicable and get it as high as you can.
Nothing but the best for my friends on this forum Mark! :)
Indeed; "wire in the sky" generally makes a good antenna - I use a 12m Spiderbeam (portable tree) and an 80m off centre fed dipole with a bit of a twist in that I use 300R TV ribbon to couple the arms to a 4:1 balun at the base of the Spiderbeam. It works very well on all HF bands.
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"I beseech you in the bowels of Christ think it possible you may be mistaken"
Oliver Cromwell, 3rd August 1650 - in a letter to the General Assembly of the Kirk of Scotland
Nothing but the best for my friends on this forum Mark! :)
Indeed; "wire in the sky" generally makes a good antenna - I use a 12m Spiderbeam (portable tree) and an 80m off centre fed dipole with a bit of a twist in that I use 300R TV ribbon to couple the arms to a 4:1 balun at the base of the Spiderbeam. It works very well on all HF bands.
I have no idea what all that means.
I just use the radio app on my phone! If i can't get phone reception i don't stress.
There are always, podcasts, and a gazillion songs on my phone sd card, and computer etc.
Live radio is always usefull, but i certainly do not intend spending any time or money trying to use whatever that stuff above is.
I tried this out on my recent trip and it definitely helped. Unfortunately, I could not get the cable vertically enough nor high enough to make a big difference. I was a bit too far from a tree and there were not many trees at the free camps I used. I have an idea how to overcome the height problem on my next trip though. I managed to pick up a couple of extra stations on the AM band and it also improved the clarity of some of the other AM stations. It made no difference on the FM band though I believe that AM loves a long aerial and FM needs a specific length aerial. You can advise better on my assumption. I have attached a pic of the cable I used and one of the extender I made. I did not need tape as I drilled a couple of holes top and bottom to thread the cable through which kept it in place. I used a fishing rod to lift it into place and again to lift it down. All very easily. As they say in Mythbusters, this is "Confirmed".
-- Edited by KevinJ on Tuesday 23rd of August 2022 11:32:25 AM
Thanks for letting me know and I'm pleased it worked for you.
To get antenna wires as high as possible I tie some light nylon string to the end of the wire (4m or 5m) and then tie an old socket (socket set type) of around 18mm size to the string. Then holding the string about 300mm from the socket I hurl it into the tree. A socket is an ideal weight as it's heavy, has a hole through it and being essentially round doesn't get caught up in branches. And when you're done just untie the socket and the wire usually falls down.
This antenna extension will tend to be more effective with the low frequency AM stations but it should help marginal FM stations too.
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"I beseech you in the bowels of Christ think it possible you may be mistaken"
Oliver Cromwell, 3rd August 1650 - in a letter to the General Assembly of the Kirk of Scotland
