A CHEAP AND SIMPLE HF QRP ENDFED WIRE
After taking a look at the miracle whip and a couple of homebrew variations on the some ideas i soon realised it was simplier to make one that i originally thought. I have to be honest that this antenna i have made has given no QSO's at the moment, i also would think its highly inefficient and for this later reason (and i only used a pot rated at 1.5w ) i just use it for RX. It does make a good RX antenna for being so simple and cheap may i add and it lets me listen to hf in any room of the house whilst giving the radio a 50 ohm match.Lets forget the feeder for a minute and see how simple this really is.....2 components...simple enough? I dont think i could build anything quite as simple as this antenna. Ok the components, first you need some wire and the length i used is about 25 feet. The second component you need is a wire wound potentiometer and the one i used is rated at 1.5w and its value is 100k. I have not ried any other values as this was the only pot i managed to salvage and sadly is rated a little on the low side for TXing hence why i use it for RX only but it does give a low SWR on transmit. Expeiment with what you can get hold of in terms of values.
As best a pic i could get of the back of the pot, note the inner coax is soldered to the centre or wiper and the outer of the coax to one of the side connections (any side makes no difference).
Another view with a surplus chunky knob fitted.
On the remaining connecter a length of wire is attached with a croc clip or can be soldered on. You may need to experiment with the wire length so that it tunes ok 160m - 10m. I read that the pot acts as variable transformer at RF frequencies. In use connect up to the radio and tune for best recieve...73's