I recently upgraded my nav plotter to a 24 inch LED TV [12v] from a 22 inch LCD monitor, mainly for the power-saving and a brighter picture. There does not seem to be any reasonably priced 12v large-screen monitors. Seeing I had a TV I might as well be able to watch it so I started looking at antennas. On my fishing vessel, I had a power stabilized TV antenna that cost a fortune but after a brief search, I stumbled onto fractal antennas. Fractal antennas are a recent invention and are what our mobile phones use.
There are plenty of articles online with plans and Youtube videos. I chose this design for its simplicity and ease of construction and made a rough one out of aluminium rod, copper wire, plywood and masking tape and tried it at home. They are supposed to be hung vertically inside a window for best performance but I was staggered how good it was! I'm about 30 miles from the towers. I rotated it, tried it horizontal and it worked great.
The measurements are in inches. I just banged nails into a bit of wood and bent the wire around. The second one I made using SS rod from an old Morse cable and mounted it on a piece of Laminex. This one is for the boat. They can be made from any wire or even aluminium foil just cut out with scissors. Cost is probably under $10 for the balun and cable and fittings if you don't have them laying about already. I rebuilt my first one, made it a bit more attractive for use at home.
Yesterday I was sailing offshore about 8 miles and still 30 miles or so from the transmitters and tested the antenna. I had it on a piece of cord and moved around the saloon, rotating it and even holding it horizontal but it was faultless everywhere. I just hung it temporarily at an angle out of the way in the end.
I will build another one without a balun for my FM radio and see how that goes. They seem to be very tolerant of frequencies.
I have seen them on the web but never got around to making one to see if they really work . I know my expensive TV aerial doesn't ,and my cheap one does ( most times ) so thank you . Time to have a go as well
Thanks Ramona, I'd heard of these but never got around to looking at it, sounds like they work a treat!
I found it difficult too to find any decent options for 12v displays, I ended up getting onto a mob out of Taiwan that have a pretty impressive range. They do variants for raw and enclosed panels, sunlight readable, IP68 etc etc, so the range is a bit daunting at first glance.
I import these, so if anyone does want a display panel let me know what options you want and I'll send you a price, it is not that difficult to get one-offs sent over on the back of a stock order, depending upon where they are at in production. This is not meant to be a sales push, there is no money in one off displays.
They make the panels from scratch, so adding or changing specific ports like a TV tuner or a RS232 port is a no-brainer, I think from memory a TV tuner adds $10 US dollars to the display.
www.litemax.com/
SB
Do you think you need a reflector on the back board? Or good signal without? Seen some with aluminum foil isolated, but behind antenna?
Do you think you need a reflector on the back board? Or good signal without? Seen some with aluminum foil isolated, but behind antenna?
I don't think so. I have my fourth one under construction at the moment. They work perfectly with the back or front towards the towers and all angles in fact. I was surprised they work so well inside a fibreglass yacht. I built that one in the photo above in SS because I thought it might have to go on the uppers somewhere.
Good wire to use is the 3.2mm TIG & gas filler wires and comes in different grades of ali, bronze or SS.
If you can't score any from the local welder or Bunnings try
www.bobthewelder.com.au/Tig-and-Gas-Rods/
Good wire to use is the 3.2mm TIG & gas filler wires
Could you expand a little (one/two sentences) about why these welding alloys would be better?
I would have thought pure copper or aluminium wire/rod would have best conductance, but I'm no expert on antennas.
I was going to use some old brazing rods myself but have misplaced the box. It's just for the ease of bending the material around the nails on the jig. I have made 3 now using stiff copper wire twisted together but you can use any metal. Coat hangar wire or cut out some aluminium foil if you like.