THE "HOWLER"

Radio Record, Volume I, Issue 2, 29 July 1927, Page 12

THE "HOWLER"

HOW TO CHECK HIM LECTURES AND TUITION NECESSARY . The ‘Howler’ is oue of the chief causes of listening difficulties. How can he be checked? Detection and tuition, supplemented by lectures, may do something, — The lure of distance reception must be recognised as one of the attractions of broadcast listening. Few who purchase a four or five-valve receiving set are content to listen only to the New Zealand broadcast stations, let alone confining their patronage to one station solely. In metropolitan and country town areas the besetting difficulty is to obtain entertainment from distant staticns, even New Zealand stations, without interference from howling valves. As the popularity of broadcast listening increases the tronble becomes more aggravated, until it has in some districts attained the proportion of a serious menace to broadcast listening. WHO ARE THE CULPRITS? One of the worst offenders is the owner of a singie-valve regencrative receiving set. With the plate (or anode) voltage of his valve frequently in excess of due requirements he sets out to ‘"rake in’? distant stations. ‘To pick them up he increases the filament volt-

; ~~ age of his valve or forces regeneration until the valve oscillates, and when the "carrier"? wave of the station is picked up he fills his neighbours’ loud-speakers | or head-phones with blood-curdling howls. The ideal adjustment for reaction is to bring it close to the point where oscillation commences, but if the receiving equipment is then, unequal to the task of reproducing the imusic, the operator of the set forces his valye into slight oscillation, and is content to hear some kind of "mushy" music, while he afflicts his neighbouring listener with howls. If his detector valve plate voltage is too high he cannot adjust his valve to its most sensitive point without "spilling over’? into oscillation. ANOTHER BORE. Another gentleman who occasions a cousideraLle amount of interfercuce is the self-imagined genius who is ont to teyolutionise radio by some marvellous discovery overlcoked by Marconi, De Forest, Ariastrong, atid others. Ue is for ever tinkering with and = altering his cirenit; he winds some wonderful coils and transformers and then sets about to startle the world. ‘The only people this pest startles are the other listeners in his district, for the howls which his set radiates rival those from a steam svren. There are, of course, very capable amateur builders and experimenters to whom the above does tot apply. AN INNOCENT DISTURBER. An innecent disturber of the peace of other listeners is the novice who operates & nentrodyne or Browning-Drake (another form of neutrodyne) which is not correctly halaneed, or neutralised. Ile has bought his set from the importers, and after a little necessary tuition gleefully reaches out for the OX (long-distance) statious. In many instances his radio set has not been fieutralised with the actual valves he is using. And some makes of valtes, ewing to mass production, vary considerahly in characteristics. ‘This resulis, in many instances, in an unbalanced radio frequeney cirenit so that the should-be harmless neutralised" set is a veritable box of liowls and squeals, ‘TO LOCATE HOWLERS. ~ "Fowlers" can We located if ¢ompetent men, with proper equipment, ate

appointed to the task. .Some Christchurch enthusiasts, a little while back, with the aid ot a motor-car and’ a loop set, located some persistent "‘howlers," ana the saine thing has been accomplished in other places. But is the discovery of these "howlers’’ a solution of the difficulty? Will this completely suppress howling? Experience, wunfortunately, proves otherwise, although some good has been accomplished. WILFUL OR ACCIDENTAL? Iustances are well known in New Zealand in which ."‘howlers" have been definitely located and proven, beyond doubt, guilty. Investigators have asked them to tune their sets, and they were shown to be causing interference. The investigators have then spent some time demonstrating the correct method of tuning and tutoring the ‘‘disturbers," yet on the following evening, through lack of skill, or intelligence, the offenders’ valves were howling as lustily as ever. In Auckland, the stations | outside this city are, sametimes, overwhelmed with a veritable tumult of howls. , TO REDUCE INTERFERENCE. There are various suggestions offered to reduce the howling valve nuisance. A house-to-house visit by radio inspectors would enable them to ascertain whether untutored people are causing the trouble unknowingly. While there "may be some persons, as in the Christchurch example, who cantiot be taught or led, there are others who would benefit by a little expert guidance. Though ‘one demonstration is worth a score of ‘lectures by broadcast, it must be re--cognised that a broadcast lecture covers wide area simultaneously, and is far sss costly than a systematic house-to-house visit. In addition to explaining how to tune a set without causing interference, the lecturer could also desclibe the test to ascertain whether a -heutrodyne is correctly balanced. Those whose sets were not properly neutralised could be advised to engage someone expert in such to readjust their circuits.