RADIO NOTES.

Wairarapa Age, 8 March 1927, Page 3

RADIO NOTES.

(BY “DETECTOR,”) Several listeners-in last Tuesday evening were again troubled by transthe writer was only able to log-in the former noises on the power lines and Sydney station, 2FC, with a fair reception. The remaining stations were practically inaudible owing to the p.ower line interference. Other causes of interference over which the operator of a receiving set has no control may be oscillating receiving sets, static and fading. It may be also that the receiver is not selective enough to tune out any single station.

Never erect an antenna parallel to a power line because this will cause maximum interference. A humming sound will be heard continuously. If the antenna is erected at right angles, the interference will be reduced to a minimum.

Quite often, a telephone exchange will cause interference, especially the ringing current which is, in places, produced by a polarity charger. The whistles and squeals which sound like broadcasting stations are often nfcar-by receiving sets operating in an oscillating condition. As sbon as the offender moves the dials, the whistle disappears. Very likely it ean be found on some other wave length. If the set oscillates, this trouble may be caused by too much regeneration or by a grid leak of improper value. Sometimes squawking results because jof the grid wire being too close to the plate element. The lead to the grid leak should bo as short as possible. This may be done at the detector tube by mounting the grid eondensor and the grid leak right on the tube itself. Too much B-battery voltage or too much filament will also the detector tube to “howl” or oscillate.

A “blooper” or regeneration set will cause interference or the receiver may fail to tune properly. If the set fails to separate stations that could be seperated before, it is likely that the coils are damp. The remedy is to remove the set to a warm or dry place. A long antenna is also responsible for “broad tuning.” Shortening the antenna improves the selectivity, although it will not overcome the trouble to any great extent if a tingle circuit receiver is used.

On Sunday evening, His Lordship the Bishop of London was heard by listeners, preaching at Auckland. The reception came in particularly well. Next Sunday evening His Lordship probably will preach at Christchurch.