Spiral aerial

I offer more practical in using a version of the spiral aerial which replaces the shtyrevy spiral aerial in length 16 — 18 see. The radio station "without the aerial", except an unusual look, will be very compact. The aerial in the form of a framework is made of the stuck together strips of plexiglas on the size of the case of radio station as its continuation in the top part that is shown in drawing.

the Framework of the aerial is pasted by p to the case of radio station and can have the various sizes depending on the sizes of your radio station. At height of a framework of 25 mm winding by a wire 0,3 — 0,5 mm should be begun having receded from the case of 5 mm. This place will give the chance to arrange more precisely the aerial shifting rounds. Winding is made before framework filling in one layer. After control rounds cover with BF-2 glue and close from above a cap from the stuck together strips of plastic in thickness 1 — 1,5 mm so that the cap did not differ in the sizes from the radio station case. To attach a cap from above to the case of radio station it is possible the M2,5-MZ screw in the middle of the aerial.

For control by transfer, supervising level of radiation in S-meter of other radio station to the aerial smoothly we bring a hand. If indications of S-meter I start to decrease, we wind off and we bite off 1 round of the aerial and we continue so further. After a while, bringing fingers to the aerial, we notice that S-meter indications at first increase, and then decrease at further approach of a hand to the aerial. It means that we came nearer to an aerial resonance. Further fine tuning we make smoothly moving apart aerial rounds on a framework and achieving a maximum of indications of S-meter.

If at the very beginning of control at hand approach to the aerial is observed by p increase in indications of S-meter, means few rounds are reeled up and it is necessary to make anew winding by thinner wire to receive on the same framework more rounds. The same method is suitable for control of any kinds of spiral aerials.