A "SICK" SET

Radio Record, Volume I, Issue 13, 14 October 1927, Page 15

A "SICK" SET

TO ASCERTAIN CAUSE. When a receiving set does not operate to full efficiency or refuses to operate it is sometimes hard to put one’s finger on the spot where the trouble lies. By using the following pointers it will be found that trouble-shooting in a set will be greatly simplified. . If a set refuses to bring the or just delivers signals that are audible one should first determine whether the aerial is in perfect condition. The loudsneaker or ’phones sliould be tested. then the batteries and the valves. If these are all perfect then start on the set proper. Simple Tests. Test all coils with a battery and a flashlight lamp to see if there is an open circuit in any of the windings. The condensers should then be tested for short circuits. Avbattery and lamp will do this also. lf the lamp lights, the condenser under the test should not be nsed. All connections from the instruments should be tested for contact and strength. As some soldering flux corrodes it is advisable to use rosin core solder for all connections; this eliminates. the chance of corrosion. ‘This information is given on the supposition that the sect is wired correctly; this is really the first point to look over. Locating the Trouble. Another thing to remember is that if the detector yalve delivers a signal and the amplifier will not, then one can be positive that the trouble lies in the amplifier. If the signals are heard in the first step of amplification and not in the second, then the trouble lies somewhere between the jack and the loudspeaker or ’phones. on the last stage. Jacks, valve socket contacts, run down batteries and poor connections are the four things that are the cause of most sets that are inoperative. Bearing these things in mind it should not be difficult for the listener to hunt trouble in his own set.