Notes and Comments

Radio Record, Volume II, Issue 33, 1 March 1929, Page 4

Notes and Comments

By

Switch

N° experienced listener harbours the fatuous belief that the howling valve nuisance can be completely eliminated under the existing radio conditions, but some measure of relief can be reasonably hoped for by educational propaganda. In the Mount Victoria area there is one individual, probably a one-valve_ set owner, who fills the air nightly with fiendish screams. This person is quite likely ignorant of the interference he is oceasioning. Possib', he is overloading his valve with "B" battery voltage, and cannot prevent his valve from oscillating. If this should meet his eye he should tap his aerial terminal with a moistened finger-tip; if he hears a loud click when he touches his aerial terminal he will know his valve is creating interference.

‘ GRID leak with a too high resistance will cause a valve to become a "howler." The resistance should be reduced gradually until the best value is found. ‘The filament of a valve which is receiving too much current from the A battery will also make a valve howl, besides shortening the life of the valve. If a set employs radio-f:eguency amplification the radio-frequenc, transformers, if placed too close, will cause howling. The transformers feed back from the plate to the grid and cause oscillation ("howling" ).

HE Sydney "Wireless Weekly" publishes the following letter from a correspondent :--J.W.R. (Croydon) .- "T have built a crystal set from the circuit published in your paper, and I cannot get results. -I am certain all the wiring is correct. The only thing I can think of that may be wrong is the catswhisker, this hair I cut off, our cat’s face is white. Should the hair be black? Kindly answer in your helpful paper?’ ‘The editor published the following answer:-"We have opportunity here to read some very amusing letters. Yours wins easily this year! Almost as funny as the reader whose aerial was attached to the guttering of his house, and his earth to a peach tin filled with water-for a crystal setmiles away from a broadcasting station! A catswhisker is the term given to the piece of coiled wire which is used to make contact with the crystal. A catswhisker usually consists of platinum, though any fine springy wire will do. BHxcuse our mirth!" All the same, "Switch" believes that the "innocent" correspondent was doing a little leg-pulling.

"THE Australian stations have bucked up considerably of late, and nearly any evening one can obtain a fair amount of entertainment from across the Tasman. In point of volume, "Switch" places the Australian stations in this order: 2BL, 2F0, 2GB, 4QG, 83LO, 2UB, 8AR. The Japs. are generally somewhat weak at present, but they have occasional good nights.

"HE SCOTSMAN," LEdinburgh’s leading daily paper, claims to be the first newspaper to own and operate its own tele-photograph service. The system used to link "The Scotsman’ with its London office is that developed by the Bnglish experimenter, J.

Thorne-Baker. Some months ago tests between Melhourne and Sydney were conducted by the leading daily papers in each capital, but due to difficulties of synchronisation the tests were not successful. New Zealand papers are wisely waiting till the process is a proved success after a lengthy trial.

EVERAL Wellington listeners share the opinion of "Switch" that the Sydney University carillon does not sound tuneful. A Sydney exchange says :-"A series of carillon recitals by Mr. J. G. Fletcher is being given: fr¥ Sydney University through Broadcasting station 2BL. Though there has been much criticism of the carillon and many friends of the University consider that it was a waste of £25,000, it is certain that broadcasting has been the main factor in enabling the carillon to gain admirers." Well, those Wellingtonians who have spoken to "Switch" on the subject express disappointment with the Sydney carillon.

YA, Wellington, gallantly came to the rescue last Friday night. The crew of the Government steamer Tutanekai were wanted urgently on board the vessel to go out to the Brothers lighthouse with a doctor. ‘The ship had just come back from a long trip round to the South Island lighthouses and the crew were glad to get to their homes. The Marine Department asked 2YA, Wellington, to broadcast a mey.. sage to the men to return to their ship, and within three hours a sufficient number of men were aboard to take the vessel to sea. WELLINGTON listeners have -observed lately a marked increase in the volume of 4YA, Dunedin. Those who reside within three-quarters of a mile from 2YA, Wellington, are generally unable to get 4YA, while the Wellington station is on the air. On Wednesday evenings, however, 2YA being silent, 4YA is now available to those who desire to hear it. "THE change back to standard time in New Zealand will give listeners a general improvement in reception of the Australian stations after the YA stations close down. Half an hour will make a. noticeable difference mye volume of reception,

EGINNERS are often puzzled over the strength of transmission by broadcast stations expressed in watts. A novice queried the writer the other day on the subject, and somehow he confused "watts" with "volts." A watt is the unit of electric power. Wattage is found by multiplying voltage" by amperage; 746 watts is equal to onehorse power. A discussion had arisen as to the horse-power employed in broadcasting at 2YA. Roughly speaking, 2YA employs 6? horse-power.