Local Distortion

Radio Record, Volume II, Issue 5, 17 August 1928, Page 15

Local Distortion

T P., Island Bay, writes complaining * of his reception from 2YA. Its failures are "to put it mildly, most exasperating," and he-states that several similar receiving sets-five valversare having a like experience. Sunday, August 5, was a particularly bad night. Because Auckland and Christchurch came in much more clearly, "it would appear that the fault lies at 2YA." f..P.’s trouble is occasioned not by the station, but by the character of the set in use. In essence the trouble is caused by having two audio valves with the detector. This causes undue distortion on the local station, although giving perfect reproduction on distant stations. This is the general tendency, but of course it does not mean that all five valvers will distort on the local station. The difficulty can be easily remedied by employing a crystal in place of the audio and detector valves for the local station. A suitable switching arrangement could be improvised so that it would be possible to revert to the audio and detector when distant stations are required... Hxperience on the same evening with an amplified crystal shows that the transmission was in no way at fault-in fact it would be impossible for the station to transmit in the manner suggested. ] Country Fading. . {s it possible to make the Wellington station more satisfactory? When IL tune in all right it will come too loud, and then it will fade away, so that it is impossible to hear it. -J.S. (Hawarden). [The trouble here is beyond the control of either 2YA or the owner of the set. It is due to his locality. Beyond a certain distance from every station ("point blank range’), the signals reach the receiver indirectly. These indirect currents are strongly influenced by atmospheric conditions, hence fading.-Ed.] ;