| OCR Text |
Show Coil, Condenser Wave Trap Is Simple Affair Wave traps are by no means new. For several years they have been used In various ways, but curiously enough few broadcast listeners have made use of them to eliminate the most frequent interfering conditions. A wave trap is a simple affair consisting con-sisting of a variable condenser in shunt with a coll of suitable size and the whole connected In series with the aerial wire leading to the tuner of the receiving set. When this trap is turned it weeds out the undeslred signal. Care should be taken In Its construction to keep the resistance at low value, otherwise the sharpness of tuning of the trap will be adversely affected and the signal strength will be lessened. The size of the coll depends on the waves to be eliminated. Thus for 200-meter 200-meter trapping a 35-turn coil will be found most effective, while for excluding ex-cluding 360-meter stations a 75-turn coll Is necessary. The variable condenser con-denser should have an approximate capacity of .001 microfarads, which Is the general equivalent of a 43-plate condenser. The manipulation of wave traps Is as simple as their construction. If while listening to a 360-meter station inter- y Wfivt TRur ference is noted from a 300-meter station sta-tion the short circuiting switch on the trap Is opened. Then the condenser Is turned until the interfering signal disappears. dis-appears. Once this Is done It will be necessary to retune the receiver, as the characteristics have been considerably altered by the adjustment of the tuned circuit in the aerial wire. |
