Listen In!

Wanganui Chronicle, Volume 77, Issue 156, 4 July 1934, Page 10

Listen In!

1 NOTES AND PROGRAMMES •&'

(By

“Detector.”)

2YA, Wellington, has developed an annoying background of late. The Third Test. Th 0 third Test cricket match will begin on Friday. Mere all-night sittings! “The Superior Type.” The majority of listeners arc turning to a superior type of receiver, an Auckland paper tells us, and the average price paid has risen from £l4 to £lB. If £lB is the price of superior sets in Auckland it is easy to understand the complaints from there about heterodyning and inability to receive stations. Grid Emission Trouble. When a mains receiver with indirectly heated valves shows a serious falling-off in performance • after, perhaps, a quarter of an hour's work, it is to be suspected that grid emission is taking place in one or more of the valves. Due to the transference of an excessive amount- of heat from the cathode to the grid, the latter may bo emitting electrons. Confirmatory evidence that grid emission is really the trouble is obtained if the. set again works normally after cooling down. Fortunately, improvements in valve manufacture have largely removed this trouble, and it is not often met with nowadays. When the symptoms of grid emission are noticed, it is to be suspected that for some reason or another the valve heaters are being operated at an excessive temperature, and in the case of an A.C. mains set it is worth while checking the connection of the mains to the tapped primary of the power transformer. If. for example, a 240-volt A.C. supply were connected to the terminals appropriate for a 200-volt supply, a considerable voltage rise would take place. American Stations. The American stations have been coming in very well, WSM, WEAF, KPO. WLW. WFAA, WHAS, KO A. WABC. NEW., WOC-WHO, KNX, WHAM. WTIC. KMOX, XENT, KSL, XfOO. WCAU, being at good listening volume at 4.45 p.m., states a local listener. KFI has been most erratic lately, being good one evening and not listenable the next. These stations are now at their maximum strength and will remain so for another fortnight. Not Affected. Second-hand sets will not be affected by the new arrangements for the collection of royalties, and the charge will not apply to valves. “Tests” Are Copyright. The Australian Broadcasting Commission warns all proprietors of restaurants that its “description” of the Tests are copyright, included exclusively for licensees, and that they must not be heard in cafes or a public place. The commission will soon have to add detectives to its organisation. Background Eliminated. Tn the last Test broadcast, by 2BL. Sydney, the annoying background, meant to bp the hum from the ground, was eliminated. A new “effect” was instituted in the bowler’s “How’s that?” when a ball hit the batsman’s pads.

New Belay Station. The popular West Coast B station 3ZK, which is operated from Greymouth, has recently installed a specia I relay station high up on the hills above Greymouth. The purpose of this station is to pick up the weak signals which are heard from the national stations in the daytime; these signals are then transmitted by land- •; line to the, 3ZR studio in Mackay l - Street, where they are amplified and ’ transmitted through the station. i Wrestling Announcer. I The wrestling announcer at 2YA has ! improved since his initial broadcast. He | still has a bad habit of whispering to i himself, which at times is almost m- ■ audible. Heard From 6WF. Last week a local listener tuned 6WF, Perth, Western Australia, and heard Mr. John Bishop, late musical director of the Royal Wcllingtcn Choral Union, engaged upon a pianoforte lecture recital. Static was some- ! what troublesome, hut trie listener, ■ who is personally acquainted with Mr. I Bishop, had no difficulty in immedi- ' ately recognising Mr. Bishop’s voice j and the recital, which had been proI viouslv given at 2YA. I ; Wave-lengths, It may be mere coincidence, but the fact remains that ail the main stations in New Zealand would appear tu be shadowing all the main Australian stations it is possible to receive in New Zealand. Perhaps the worst example of shadowing is noticeable in the case of 2YC and 2BL. In the Wellington area, at any rate, it is virtually impossible to receive 2BL at all comfortably until 2YC closes down. Christchurch shadows Adelaide, one might add, and Dunedin shadows Melbourne. Wellington is uncomfortably close to 2BL, Sydney. Moreover, IYX Auckland, shades a common wave-length with Perth, and IYA is only 15 kilo-

metres off Crystal Brook. Down among the shorter waves reception in New Zealand is becoming increas l ng]y marred by a series of whines and moans that emanate from the smaller fry in Australia. There is, in fact, one particular band, somewhere about 350 metres, that has become a hopeless tangle of conflicting heterodynes and whistles. The time, must inevitably come when the whole problem will have to be faced. It is significant that there is already a. movement afoot in Europe for few stations and strong ones. Aerial Lead-in. No apology is needed for returning to a subject that is older than broadcasting; reference is here made to the aerial lead-in, a collective term generally applied to the connecting wire and its insulator by means of which an external aerial is connected to a receiver inside the building. The ordinary lead-in insulator of commerce, consisting of an ebonite lube and a central metal rod fitted with terminals at each end, would seen! to be far from satisfactory. Poor connections, especially at the outside, end, have often been proved to be responsible for an effect that is mistaken for fading. A strong case can- be made out lor maintaining a continuous and unjointed metallic circuit from the end of the aerial to the receiver terminal. But it is usually inconvenient, to lead the bare aerial wire right up to the set. and so at least one soldered connection becomes necessary; whatever one may think of the desirability or otherwise of soldering, this is certainly a case where it is to be preferred to any other kind of joint. An insulated guy rope to the ground from the aerial is an advantage, the aerial wire being led to the insulated rubbered wire passing to the ebonite or glass tube through wall or window. A knot in the insulated wire at each end of the tube prevents displacement. The tube should be inclined downwards to the weather.

i Typical Wrestling Broadcast. “Talker has a head scissors on Roloff . . . Talker has a head scissors on Roloff . . . Talker has a hoau scissors on . . . No! Yes! . . . Talker has a head” . . . and so on till Ihe ninth time. Then “round and round they go in the referee’s hold . . . round and round” . . . till the ninth time. Next, “He can’t get out of this” . . . here again till the ninth time. V/onderful stuff. This repeating is a blot lon these relays. The trouble is that | some announcers persist in chattering i when they have nothing to say. j Setting of Trimmers. Experienced amateurs do not. need to be reminded that the adjustment of a trimming condenser is by no means “straight line frequency”—or, for the matter of tha.t “straight line anything.” At the position of the adjusting screw corresponding to roughly minimum capacity, a full turn has little effect in varying the frequency l c-f the circuit which it controls, but at I nearly maximum position a small fraction of a turn makes a clearly perceptible difference. This explains partly why the practice of starting lhe operation of trimming at random is often ’productive of disappointment, or at any rate of an unnecessary waste of time. It is generally worth while going to the trouble of seeing that the trimmers are set initially to roughly the middle of their useful working range. This condition ran generally be achieved by screwing each control of the “all-in” position (right hand), and then slackening back each screw by a couple of turns, or even slightly less. It may be that by following this j plan an unnecessarily large amount of ; trimming capacity is included in each i circuit. But even if it is, after hav•ing found a good adjustment it is easy to make progressive reductions of capacity until one can go no farther with- | out impairing the alignment of the circuits. Triple Control. Neighbour: How many controls art* on your radio set I Owner: Three—my mother-in-law, my wife, and my daughter

Benefits of Coverage. It is an open secret that the radio experts are more than pleased with the practical coverage results following the erection outside Christchurch of the new transmitter. Not only has this new station given results greatly in excess of theory, but it continues to give consistent results winter and summer. Over the sea the range seems to bo calculated in hundreds of miles, while over thick bush anu even across rugged mountain ranges signals come in far more reliably than was ever anticipated. Considering that the new transmitter at Christchurch is only 2| kilowatts in power, results obtained when the Auckland transmitter of 10 kilowatts is working should be extremely satisfactory. One fact that requires stressing in connection with the good results obtained is that the long and painstaking spade work undertaken by the engineers when selecting sites has not been time wasted. In the old days stations were sited by instinct and guesswork (states an exchange). All that has changed. The engineers responsible deserve their spade work to be recognised more than it appears to be by the outside public. A Generous Grant. An official return shows that the Government grant to the British Broadcasting Corporation fur this year is £1,950,000. Of this the corporation has agreed to forgo £250,000 by way of contribution to the exchequer, lhe actual payment amounting to £1,700,UOO compared with £1,518,00 for 1933. “Death at Mast’s Head.” Last week-end ’s tragedy at Tauranga of the youth who was electrocuted while he was endeavouring to free his father from a wireless aerial which had fallen across electric service wires has again raised the question of regulations regarding the proximity of aerial masts and wires to the ordinary wiring system. The general manager of the Auckland Electric Power Board (Mr. R. H. Bartley) states that there are no regulations governing the erection of wireless aerials, but we have reason to believe that Mr. Bartley is wrong. There is a definite regulation to the effect that no aerial wires or stay wires shall cross above power lines or be so placed that, in falling, they may foul the live wires in any way. This regulation is clear enough, but the difficulty appears to lie in its enforcement. In crowded city areas it is often next to impossible to erect an adequate aerial that, in lhe event of a fall, would not come into contact with electric wires.

Th e handling of aerials has been responsible for several tragedies in Xew Zealand lately and, while the number is not alarming when one considers that the country has more than 120,000 radio sets in action, it serves to drive home the. necessity for the more careful handling of the equipment connected with radio reception. Properly handled radio is the safest of all electrical appliances—a statement that is backed up by the fact that there has net been one death in New Zealand directly attributable to shock from an all-electric set. But there are households in which the electrical contrivances are being misused. Electricity departments in various towns have received an increasing number of complaints from householders whoso lighting fuses have been blown out. In many cases it has been discovered that radio sets, installed by persons who know nothing of electrical hazards, have been at the root of the trouble. The use of the power mains lor aerial or earth wires is another source of danger and was the result of a distressing tragedy at Brooklyn, Wellington, in 1931. Electricity is a good servant but it can show a dangerous side if it is carelessly handled. All-wave Sets popular. A remarkable advance in the performance and popularity of nil-wave receivers has been evident in Wanganui recently, and it. may confidently be expected that the all-wave set will continue to win the approval of listeners. Ono set tested (H.M.V. model 111) brought in the distant short-wave stations with exceptional clarity and volume, the reception of French anil German stations in particular being well-night faultless. On the broadcast band, also, a wide range of stations was heard, the tone being unusually fine. Radio Repair Sendee. Make use of our Radio Repair Service. Radio is our specialty, therefore bring your repairs to the firm who specialise in this work. All and any classes of sets repaired. Valves may be the cause of poor reception, so bring them in, and we will test them free.— D. A. Morrison and Co., Avenue.* THE PENETRATION OF ROCK BY RADIO WAVES A short time ago research work wacarried out at the Mammoth Cave, Kentucky, UJ3.A., under the joint auspices of the U.S.A. Bureau of Mines and the Geological Survey of Canada. The disputed question of the extent to which radio waves will penetrate into the earth has a high scientific interest and it. bears directly on some practical modern methods of geo-phy-sical prospecting for underground metals such as the sulphides of lead, iron and copper. ITevious investigations had been made at the Caribou Mme, Colorado, and in the Mount Royal tunnel at Montreal. The results of all this work has been of a dubious nature because of the presence of iron pipes and rads, and of copper conductors connected with electric wiring. There were three schools of thought; some claimed that the radiations came through the entrance, others that the waves passed through the rock, while the remainder considered that the enccts were transmitted along the wires and pipes. Probably all three paths tire avail able, but certainly the Mount Royal experiments proved beyond question that waves of about'4o metres failed to enter the tunnel for more than a few hundred feet by any of these means. Longer waves in the broadcast band were heard and measured throughout the entire three and a halt miles of the tunnel. To settle the question the Mammoth Cave in Kentucky was selected for the experiments, and it proved n fortunate choice. This cave had not been illuminated by electricity, and the manager was good enough to have the telephone wires removed. There arc no conductors in the cave except for short lengths of iron handrails here and there. The exits are filled by and sealed with the waters of the Echo and Styx Rivers. A few years ago ft new entrance was found and some electric wiring introduced; this is four miles away overland, and eight miles distant by cave.

A careful survey was made both under and above lhe ground so that corresponding points could be locate<l and levels known. Most of thf» work was carried out with an overburden of three hundred feet —about two hundred feet cf limestone capped by about one hundred feet of Cypress sandstone. It was found that the resistivity of these rocks was in the neighbourhood of 15,000 ohms per cubic centimetre. Broadcast Wavelength. The words and music from Louisville. Nashville, ami Cincinnati were received on a portable six-tube super het set similar to those used, by the Telegraph Department a few years ago for tracing interference to radio- listeners. These signals were traced from, the entrance of the cave inwards to a*bout five hundred feet when they died away, but they reappeared quite strongly at about one thousand feet from the entrance. It is interesting to note that the overburden was approximately Iho same throughout, namely about 150 feet. During the next night signals were received from echo at a depth of about three hundred and forty feet. The conclusion is irresistible: the waves from the distant stations can be detected under three hundred feet of lime rock and sandstone. These waves certainly do not come through the entrance of the cave and they do not pass along conductors.

Long Wave Stations. Morse signals from about six sta tions were heard on the loop aerial. These signals were quite readable, but it was not possible to measure their intensities, partly owing to statics. The wave fronts appeared to be mainly vertical, and the waves must, therefore, have been travelling through rock rather than down from above. Bearings and signal strengths were obtained also above ground and while there was an increase in the signal strengths above the cave, the bearings were identical. This picture of a wave with its front nearly vertical travelling through the rock just as though it was air is rather novel. It was possible to pick up these Morse stations with a. loop consisting of throe turns of wire on a. four-foot square frame. Horizontal Wave Fronts. A circular horizontal transmitting loop, 100 feet in diameter, was placed on the ground, and the insulated wire could be tapped so as to give one to ten turns as required. A rectangular receiving cod of three turns covering an area of forty by ten feet was placed on the floor three, hundred feet below the ground. The transmitter was caused to induce n current of half an amp. into one turn of the transmitting coil. The frequency of the radiation was then varied by stops of ten from 20 to 110 k.c. It was a most remarkable fact that frequencies of about, 2( to 30 k.c. boomed out strongly, whereas those above 30 k.c. were weakly received. The transmitter was shifted until there was nine hundred feet of solid rock between it and the receiver, and the only conclusion is that the radio waves passed through this medium because the loop receiver indicated that lhe signals came from the transmitter by direct path. —‘Coherer.’ »

IYX—A ackland. (880 Kilocycles.) 5.0: Light musical programme. 6.0: Cloß down. 7.0: After-dinner music. 8.0: Alterna tivc concert programme. 10.0: Close down. 2YA. WELLINGTON. (570 Kilocycles). 7.30 to 8.30: Breakfast session. 10.0> Chimes. Selected recordings. 10.30: D<?.ch tional service. 12.0: Lunch music. 2.0: Classical hour. 3.0: Sports results. 8.15: Light musical programme. 4.0: Sports results. 5.0: Children’s hour. ff -. 0: Dinner music. 7.01 News and reports. 7.30: Talk. Our Gardening Expert. 8.0: Chimee. Recording, Military Bands. 8.5: Eddie Pola and Com. pany, sketch. 8.13: The Casino Orchestra. 8.16: Richard Crooks (.America’s famoui tenor). 8.19: Jimmy Dorsey (America’s lead, ing saxophonist). 8.22: “Music Round the Camp Fire.” 8.37: Philadelphia Symphony Orchestra. 8.40: J-ecturette, Dr. Guy H. Scholefield. 9.0: Weather report and station notices. 9.3: The Commodore Grand Orches-

tra. 9.7: Rhondda Valley Male Quartet. 9J(i; Han-y Sculthor|>e’s Novelty Band. 9.16 j Sketch. “Do You Remember?” 9.22: John Hendrik- .tenor. 9.25: Roy Wilson and Hm Wurlitzes. 9.31: C. B. Cochran (comperei. assisted by Elizabeth Welch. Edward Cooper and Ray Noble and His Orchestra. 9.39: Mickie Edwards and Phil Hall. 9.45: Gladys Knight, contralto. 9.18: Ernest. Leggett’s Orchestra. 9.51: Thorpe Bates, baritone. 9.57: The Commodore Grand Orchestra. 19.0: Music, mirth and melody. 10.30; Dance programme. 11.0: Close down. tYC. WELLINGTON (840 Kilocycles.) 5.0: Light musical programme. 6.0: Close down. 7.0: After-dinner music. 8.0: Alten>a« tive concert programme. 10.0: Close down. 3YA. CHRISTCHURCH. (720 Kilocycles). 7.0: Breakfast sessiop. 8.30: Close down. 10.0: Devotional service. 10.15: Selected recordings. 11.0: Talk. 11.15: Selected recordings. 12.0: Lunch music. 2.0: Classical music. 4.0: Light musical programme. 4.30: Sports results. 5.0: Children’s hour. 5.0: Dinner music. 7.0; News and report*. 7.35: Addington stock market reports. 8.0: Chimes. Relay of Concert Programme from 4YA, Ihmedin. 9.0: Weather forecast and station notices. 9.8: Reserved. 9.20: Presentation of 8.8. C. Programme, "My Adventure at C’hislehurst.” 9.52: Recording, Descriptive sketch. Jack Hulbert and Company. 10.6: Dance music. 11.0: Close down. BYL, Christchurch. (1200 Kilocycles.) 5.0: Light musical programme. 6.0: CIoM Icwn. 7.0: After-dinner music. 8.0: Alternative concert programme. 10.0; Close down.

4YA, DUNEDIN. (790 Kilocycles). 7.0; Breakfast session. 8.30; Close down. J 0.0: Selected njeordings. 10.15: Devotional service. 10.15: Selected recording*. 12. 1 Lunch music. 2.0: Selected recordings. 3.30: .Classical music. 3.45: Sports results. 4.3< : Light musical programme. 4.45: Sports results. 5.0: Children’s hour, conducted hy Aunt i Leonore. 6.0: Dinner music. 7.0; News and reports. 8.0: Chimes. Special Concert Programme by the Concert Orchestra and The Facuiiy Players. 10.2: Favourites, Old and New. 10.30: Dance music. 11.0: Closedown. 4 YO Dunedin. (1140 Kilocycles.) 5.0: Light musical programme. 6.0: Closf down. 7.0: After dinner music. 8.0: Al« ternative concert programme. 10.0; Clo»l down. 4QG. BRISBANE. (760 Kilecycles). 6 p.m.; Music; •hipping news, etc. • ISi Children’s session. 6.45: Music and waaihet reports. 7.0: Studio music. 7.23: News sen vice. 7.45: General sporting information. B.oj Studio programme. 10.30: Dance mnsie. 11.0; Close down. 2BL, SYDNEY. (353 Metres). 6.15: Dance murfr. 7.5: Country aeesioft* f. 20: Recorded music, 8.0; Studio concert programme. 2FC, SYDNEY. (451 Metres). 5.45 p.m.; Children’s session. 6.45: P* eorded music session. 7.20: Sporting and news. 8.0: Studio Concert Programme.