LOCAL WIRELESS

Ashburton Guardian, Volume XLIV, Issue 10131, 7 June 1924, Page 5

LOCAL WIRELESS

ASHBURTON WORKS SYDNEY.

DOINGS AT 3AL, V 1(; . Y ' ■ •‘ t> •j. Last night was a reddetteri'night for the local radio station 3AL, as twoway communication was established

with Sydney -for the first time. At 9.<15 p.m. a general call to Australian stations was sent out, and was immediately, replied to by 2DS, Sydney, the station owned by Mr Jack Davis, the young amateur who recently accompained Mr MacClurcan on the “Tahiti” in a venture to find out. tire possibilities of long-disance shortwave communication. Mr Davis reported the local station veiy loud;' but fading rather badly. ; Usually HAL’s signals are reported; free from fading,.. . but as more than the'usual' power was being used, and as this adjustment gave fading on previous occasions, it is hoped to reduce Kwer and lessen the fading, and still comfortably strong in Sydney. •v Mr.,.Dawson says that he was consideraMy interfered with by the owner of a badly radiating set, the trouble getting, so bad that the last message' from 2DS was lost, and 3AL had to close- down as- if-was impossible to read : 2D.S through. the interference. It has been pointed out in these columns before what a nuisance a reradiating . set causes, aiid by the way last night’s interference came in,, the offender was using a prohibited circuit or a standard circuit very badly handled. Possibly the offender was unaware of the nuisance caused. In this case the following test would prove useful to him and perhaps an eye-, opener; If the damped finger placed on the aerial terminal of the set alters the received signal in any way, and particularly if it causes a “pop” in the telephones, the circuit is reradiating, and therefore acting as a transmitting set, contravening the regulations. A loop receiver has been arranged, and it will be possible to identify the offending .station next time, when the matter will be placed in the hands of the Radio Inspector. Mr Dawson is loth to do this, however, and it is hoped the offender will not make this necessary. Some low-power tests conducted with 2AE (Mr Patty, Gisborne) proved of interest as indicating the results obtainable on a very small power input. The first test was on 6.4 watts input—the normal power used at 3AL, and the report ,’waS “signals strong.” 3AL then reduced power to 1.6 watts input, and Signals still being strong, .35. of a watt was then tried, and the report came back “jake.” The next step was a big jump down to .012 of a watt input, with only 12 volts- on the plate of the valve and 1 milliamp (one-thousandth of an ampere) flowing through the .valve. 2AB heard this distinctly, but could not read it all due to interference from a neighbouring transmitter, but expressed the opinion that he could easily read it if interference was absent. 2AE’s set* then developed trouble and lower tests [ had to be postponed. As the transmitter at 3AL has been re-tuned since then,” 5 it is hoped to get still better results next time low-power tests are conducted. The average torch bulb consumes approximately 1 watt, and the- power used at 3AL was about one-eighth of this—to signal 500 miles. Daylight tests with 2AE were arranged for the King’s Birthday, but proved unsuccessful. It is hoped to arrange some more tests in a few weeks’ time, as approaching school examinations are monopolising Mr Daw- i son’s attention at present. j