THE RADIO WORLD

Southland Times, Issue 18972, 20 June 1923, Page 7

THE RADIO WORLD

(By

“Regenerator.”)

ONE VALVE RECEPTION. LOCAL AMATEUR’S FINE RECORD. A local amateur, Mr Frank R. Rose, sends the following letter:—“lt might interest your readers to know that the following broadcasting stations have been heard in Invercargill on only one valve:—l Auckland IYA; Gisborne 10 watts; Wellington 15 watts; Mr R. J. Orbell, Christ- | church, 15 watts; Dunedin, 4 YB. Welling- : ton, Monday and Friday, comes in very I strongly. The whole concert is easily tuned jin. Last Friday and Monday I picked up the music using one stage audio frequency i amplification, with an iron bed frame in place of an aerial. - The carrier wave was ' quite audible using only the short wire lead to the bed as aerial ... a matter of about four feet of 26 ga. wire. This rei ception of a 15 watt station 450 miles away I is unusual. Using two stages audio recep- . tion with loud speaker is quite practic- , able, in fact using a Brown loud speaker, on only one stage audio, a local amateur | brought in Wellington on Monday last loud enough to be heard all over a small | room.” i In thanking Mr Rose for his highly in- ! teresting communication “Regenerator” would venture to express the hope that I other Southland amateurs will follow suit i and send in records of their achievements, which will be gratefully received. BROADCAST RECEIVING. BEST TYPE OF AERIAL. An American company engaged in the manufacture of radio goods thus describes the correct form of aerial for broadcast reception:— The ideal antenna for broadcast receiving is a single wire about 110 feet long, including the length of the lead-in wire. Following are important facts to be kept in mind, and, if heeded by amateurs, results would be apparent immediately. “1. The aerial should be a single wire (preferably No. 14 copper wire) not less than 40 feet nor more than 80 feet in length (commensurate with lead-in). The higher the aerial the better. “2. The lead-in should be soldered to the aerial, unless constructed of one wire and led direct from the aerial. The lead-in should be kept away from the wall at least one foot or more, to prevent losses. “3. Ground wire should be firmly clamped or soldered to a radiator or cold water pipe, the surface of which must be scraped clean and free from paint and rust. “All of the above facts are of paramount importance in the installation of the aerial and should be adhered to faithfully.” A single wire aerial is better than a twowire aerial because for shortwave reception the greater capacity of the two-wire aerial is not desirable, as it might be necessary to reduce this by means of placing capacity in series in order to bring in, for instance, the short wave-length broadcasting stations, and that would mean a certain loss of efficiency. This naturally supposes that full advantage can be taken of length, but where this must be limited, then the twin becomes desirable owing to its increased area. If, however, owing to a twin aerial being unavoidable, the free-ends of the two wires should not be joined to-

gether. The two wires, which are otherwise quite separate, are joined at the instrument end of the aerial by taking a down lead from each and soldering these together to one common lead-in wire a few feet below the aerial. An ‘earth’’ lead should be short because a maximum of current flows at the earth end of the aerial. This cun-ent must flow through the earth connection from the aerial to the earth, and, by virtue of its being an oscillating current, from the earth to the aerial. Therefore, if the earth con- | nection is long, its resistance will cause i loss of current. I RADIO AND COPYRIGHT. j The Westinghouse Electric Company have announced that W.J.Z., its New York broadcasting station, will discontinue sending out copyright music at the result of the demands of the American Society of Composers, Authors and Publishers. The station cancelled the broadcasting of “Robin Hood” because of. the demand of the Society that a license fee arbitrarily fixed at 5000 dollars be paid to it for the privilege of broadcasting music of which it controlled the copyrights. . Other broadcasting stations have refused to consider the demands of the Composers’ Society, and at a meeting decided to continue to broadcast music regardless of whether it is coypright. The Westinghouse Company is not a member of this Society. W.J.Z. and other broadcasting stations will be unable to broadcast the music of hotel orchestras, which invariably play copyrighted music. The license fees are still in the experimental stage, and will range from 200 dollars to 5000 dollars, but an equitable basis will be fixed after the matter has been tested. If stations wish to keep up the high standard of music played they will either have to pay the fees or close down, as nearly all the best music is copyrighted. SPARKS. There have been numerous incidents reported lately of people seemingly deaf to ordinary conversation who are able to hear wireless signals quite easily. Among the theories advanced to explain this is that the condensation of the sound waves which in the case of ordinary headpieces are directed straight into the ears, tends to act in the manner of an ear trumpet, as it were. Another feasible explanation is that the headpieces pressing directly on the skull-bone transmit to it the vibrations of the diaphragms mechanically. A wireless concert was arranged in the Wellington Town Hall concert chamber last Friday evening by Mrs Eleanor Hampton in order to raise funds for the purchase of a receiving set for the Ewart Consumptive Ward of the Wellington Hospital. Unfortunately the public failed to respond and the affair was a total failure financially.

In the Thomas transmitter, a recent American invention, a minute electrical discharge takes the place of the mechanical disc-microphone This discharge flows between two points, separated by a very small fraction of an inch. It is affected by sound waves, just like the diaphragm, but being non-material and having no perceptible inertia, it responds equally well to all vibrations. Hence, it is claimed, music broadcasted by means of it is transmitted in all its original purity. Good progress is being made in the improvement to the transmitting station on the top of. the big Ford building (Courtenay Place, by Wellington Broadcasters

Ltd., says the Dominion. The new 50ft mast has been procured and prepared. It will be erected next Saturday afternoon. The readjustment of the transmitting set to enable the present 15 watts power to be increased to 250 watts will be complete in about ten days’ time. Radio amateurs can rest, assured that the new station will be a great acquisition and some good programmes are now being arranged. The Radio Society of Christchurch made a good start last Saturday afternoon in the erection of their broadcasting station in the Robert Francis building, High street, says the Christchurch Press. Two 32 feet Oregon poles were erected, giving an aerial span of 53 feet. The aerial is to be of the battleship cage type, using a counterpoise. Al 5 watt set will be used. The R.S.C. intend to build a 15 watt C.W. transmitting set for the coming TransTasman tests. Various other leading Christchurch amateurs are busy getting their “squeak boxes” but together, so Christchurch should put up a good performance. The first grade 1 transmitting license for Christchurch has been granted to Mr J. Orbell, St. Aiuaiis. Call letters will be 3AA, and of 155-165-175 meters. Both ’phone and C.W. will be used. A canvass taken of the wireles sets in the United States showed that about 1,500,000 sets were being used.