WIRELESS IN THE HOME.

Otago Witness, Issue 3593, 23 January 1923, Page 60

WIRELESS IN THE HOME.

PRACTICAL POINTERS ON AERIALS. The out-of-doors antenna has been named as obsolescent, but it is still very much in evidence, and must remain so until elaborate tube sets are brought within range of short purses; so any practical hints about its construction or operation are always welcome. In ltadio Journal (Los Angeles), W. S. Xtandiford gives a lew “pointers’’ that will interest apartment dwellers in particular : “Radio amateurs living in the same building often connect their receiving instruments to the same antenna so as to save extra work and expense, and then wonder why their sets do not work satisfactorily. Theoretically, it would seem that such a proceeding would work well, but practical experience shows that it will not do so. This is due to the fact that it is not possible to tune the two sets exactly with each other. But even supposing that it was feasible, another factor enters which is as follows : Suppose that the amateurs tuned to a wave-length of 360 meters; as each instrument has a certain amount of wire on the tuning coil, etc., this combination would result in a double oscillation, making the tuning really 7ko meters, which would defeat the purpose intended. “If two sets are in use in the same building, and both radio fans would like to “listen in’’ to broadcasted concerts, etc., then how shall aerial equipment be provided ? There are two possible methods by which this can be accomplished. The first is that two outside antennas be erected on the same roof. This will work well with the crystal sets and no trouble will be experienced, even if they are placed reasonably close together. Tube sets can also be used if their antennae are spaced far apart and run in different directions from each other. In connection with this type of apparatus it ought to be remembered, however, that regenerative sets having bulbs are actually transmitting a continuous wave at the same time that they are receiving, and so if it should happen that two sets tuned at different wave-lengths are using separate aerials in close proximity to one another, there will be interference. “The other possibility is in the use of a small antenna inside of the building, preferably in the room where the set is located. Amateurs must remember, however, that an indoor aerial never gives as good results with regard to loudness of signals, etc., as an outdoor one, this being due to the absorbtion effects of electrical wiring in the house or the steel framework if in a large building.”