2006-10-28 05:38:06 · 5 answers · asked by Rodge 1 in Science & Mathematics ➔ Engineering
Are you trying to make a choke? An inductance? The fewer the turns the higher the frequency. For VHF you would maybe need 8 turns. For medium wave I used to wind a coil around the end of a cardboard centre of a toilet roll holder! From end to end would usually get the medium wave AM. Less turns and I got short wave. I got India with a length of wire as an aerial about 15 ft long, a toilet roll inductor, a variable capacitor and a germanium diode connected to a pair of headphones on short wave. I was only about 8 years old - I can do better than that now! lol. Top band is usually refers to the 2 metre band. You would probably use a smaller diameter core and wind on maybe 10 turns. I'd just forget it and buy a radio if that is your purpose. Of course Inductors can be used for other things! Good luck with it whatever you are trying to do! The formula for the reactance of an inductor is X = 2 * 22/7 * F * L (F = frequency L = inductance in Henri's.
2006-10-28 05:52:41 · answer #1 · answered by Mike10613 6 · 0⤊ 2⤋
Wow, I wouldn't even try to use 40' of wire on 160 m. I trust you're talking about a vertical. The bandwidth and the radiation resistance will be so low that it would be almost useless. Check the latest ARRL handbook for their inverted L antenna or for top hat capacitive loading to get some better results. Low Band DX'ing (ARRL) is another good source of info. If you still want to go with 40' of antenna, either book will have the info you want.
73
2006-10-28 13:15:41 · answer #2 · answered by Gene 7 · 0⤊ 2⤋
oh i,m sorry i left my clever hat at work
2006-10-28 12:48:47 · answer #3 · answered by Anonymous · 0⤊ 2⤋
http://www.youtube.com/watch?v=RlVHs0Wo9S0
2006-10-28 12:45:05 · answer #4 · answered by Anonymous · 0⤊ 2⤋
and the reason i would know this is????
2006-10-28 12:40:34 · answer #5 · answered by mousie 4 · 0⤊ 2⤋