Radio Broadcast (May-Oct 1922)

RADIO BROADCAST 55 THE PORTABLE RECEIVING OUTFIT Which also can be used as a radio telephone transmitter. Current for the operation of the vacuum tube is supplied by a single dry cell now consider its ability to receive, leaving the transmitting for consideration anon. A PHENOMENAL RECEIVER WE HAVE become so used to thinking of radio in terms of kilowatts, and towers and what-not, that the suggestion of a really compact receiving outfit, operating from a single dry cell being of much value does not seem very likely, but in this instance we have erred. Many of these receiving outfits are now in use and there is nothing more interesting than putting one of them through its paces, for an agreeable surprise is generally the result. For instance, there is a gentleman in Jersey, who could not tell one letter of the code from another, were it to be transmitted to him at five words a minute, nor does he know the difference between a condenser and an inductance, and his ideas concerning wave length could never be found in any book on radio, for he hasn't any, but he has installed one of these receiving sets. The aerial this gentleman boasts is a single copper wire, about eighty feet long and thirty or thirty five feet above the ground. Would it surprise you to know that he was able to receive wireless telephone speech very clearly from a vessel nearly a thousand miles at sea, during the day? There are a number of similar installations in Brooklyn and it is quite a common thing for these stations to listen to the transmitting from the broadcasting station, located in East Pittsburgh, Pa., even though no effort is made • to instal pretentious aerials. Most of those which have been observed are of the single or two-wire type, generally fifty to one hundred feet in length. With such a receiver is it strange that a new era has dawned in Scout communication? AN EXCEPTIONAL TRANSMITTER AFTER considering the wonderful im, provement in radio receiving apparatus, which now makes it possible for us to listen to wireless telephone conversation over distances of many miles, with very simple equipment, it is even more astounding to learn that this same outfit may be converted into a transmitter by merely making an adjustment or two, removing the receivers from the head, and talking into one of them. In order to transmit, it is necessary to have the bulb oscillating and this condition may be recognized by a mushy sound in the telephone receivers. When this occurs, it is merely necessary to talk into one of the telephone receivers and the speech, thus transmitted may be picked up over short distances. A low resistance microphone placed on the ground lead will give slightly better results. It is not necessary to throw any switches in transferring from transmitting to receiving, but it is necessary to alter the "tickler" knob a little, in order to cut out the mushy sound when reception is being carried on. If this were not done, the incoming speech or telegraph waves would be distorted and in the case of the former, might be unintelligible. FIELD OPERATIONS SCOUTS on field manoeuvres may conveniently carry one of these stations with them, and where several troups are to be directed from a single headquarters, it is generally found advisable for the headquarters station to be equipped with a more powerful transmitting station, while the various troops may