When a Set Refuses to Function

Radio Record, Volume II, Issue 37, 28 March 1929, Page 31

When a Set Refuses to Function

F your newly-built set, when put on test, shows signs of activity but refuses to pass signals, it may be assumed that the amplifying section is O.K., but that something has gone amiss with the detector or H.F. section. The plate circuit can be tested by withdrawing and reinserting one of the H.F. plugs. This should cause 2 click, A similar click should occur when the loudspeaker leads are connected. If it is possible to hear a gentle rushing noise, it can be assumed also that the filament circuit is in order, and if the valves are of a type that functions with a glow, it will be possible to see if this is so. When no signals-not even Morse signals-can be heard, it. may be concluded that the aerial, though connected, is not in. circuit. with the rectifier. This is a very.¢ommon trouble, and is generally traceable to-a:badly fitting grid leg. If éxamination and a slight spraying out of the grid leg fails to provide a remedy, the coil connections should be checked and, as ‘in the case of the valve pins, the plug should be opened or sprayed. Contact of the most perfect order is essential everywhere, but more particularly in that portion of the set over and through which the very weak aerial oscilaltions are con- . ducted. .