Radio Antenna Design

AERIAL IS PUZZLING

TO MANY AMATEURS.

First Thing to Insure Success

Is to Place Wires Properly.

The aerial still remains a stumbling block for many radio fans. There is usually very little trouble with the set after it has been used for a few weeks, but the outdoor work is not so easy. The best set is useless with a poor aerial so be sure you have a good aerial if you expect good results.

Before you buy any wire or insulators, go up on the roof of your house and look it over. For receiving only, a single wire is all that is needed, and it should be as long as possible, up to about 600 feet. Big poles are not needed.

The wire can be fastened to any convenient chimney, pipe, of skylight. The aerial need not be confined to one house. If you are a city dweller, and are surrounded by other buildings, investigate the possibilities of stretching a wire to a house several hundred feet away. If it is a few feet below the level of the walls, do not worry: a few feet difference in height in a receiving aerial has very little effect on reception.

The lead-in, if possible, should be taken off the aerial all in one piece — that is, simply twist the wire through the insulator, and bring it directly down to the lightning arrestor.

Aerial for Short Stretch.

If the aerial is limited to one building and the longest possible stretch is only sixty feet or so, a three or four flat top aerial will be a little better than one wire. Remember this holds true for very short aerials, where one wire would have little capacity. The spreader to hold the wires need not be more than five or six feet long; an old broom handle will serve nicely. A small insulator is put on the end of each wire, and the other end of the insulator fastened to the spreader. If desired, a small mast can be put up, and the aerial suspended from that, but this need not be done except when the roof has many obstructions, and it is necessary to clean them.

Proper Wire.

A word about the right kind of wire to use would not be out of place. For stretches up to eighty or ninety feet, ordinary No. 14 copper wire will do. For shorter lengths, No. 18 can be used, but its use is not recommended as it will sag badly in hot weather. The best all-round wire to use is seven-stranded copper or phosphor bronze.