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Show : DUNCAN TELLS MORE ABOUT SENDING RADIO T Standard-Examiner Expert Invites Questions From Young Fans BY K. 1 Dl SCAN Director. Radio Institute of Aincrii.i. Continuing our trip around the ir-enlt ir-enlt with a vli"eleis wave, we find that the spark gap ix the DOXl Bt p after tlie condenser. The purpose of this gun is to discharge dis-charge the energy stored up in the condenser in the form of radio fre-quehcy fre-quehcy isciilation. it also quehi lies the spark that Is. restores the gap to Its non-conducting slate when Its energy has been passed on to the antenna circuit The most popular form of spirk gap the quenched. It has several heavy copper plates separated by insulating in-sulating washers These are placed a rack or bidder and pressed tlifhtb together b means ol a pressute bolt. The distance between each i upper plnte is not over 1-100 of an Inch. The sparking surface insid.- the gup Is ab-SOlUtel) ab-SOlUtel) airtight to prevent leakage and sparking which would cause a loss In (lit output of the current. Bach gap requires about 1200 trolts. I'siiiK 20.000 oits approximately 17 gaps wcuid bo employed OSCILLATION TRANSFORMER. Xext comes the oscillation transformer trans-former consisting of a prim.iry and secondary winding. The primai-' of this is In the closed circuit (consisting (consist-ing of all puvts heretofore described) and the secondary is In the open or antenna circuit! The function of the OSClllaliOn transformer trans-former ie to transfer the energy from the closed circuit to the open By n . n-i i i , t he va . ! 'tig! h of -j 1 1 1 i eitcuit can be Increased or decreased by varying the self-inductance of eitticr the primary or ondary coll, ASK DUNCAN! R. Li. Duncan, the Standard-Examiner's Standard-Examiner's radio expert, is pio-pared pio-pared to write on any phase of wireless telephony on which Og-den Og-den enthusiasts want him to write. It is impossible for Duncan to answer individual questions but he will gladly take for his subject.-, topics suggested by readers. So you are Invited to write Duncan, telling him your desire.", at thia address: R. L. Duncan, director. Radio Institute of America. Amer-ica. Worth street. New York Write direct to Duncan, not to the Standard-Examiner When the limit of charge has been reached in the condenser. It discharges - through tip? primary winding of the oscillation transformer across the spark cap. This discharge consists of a number num-ber of radio oscillations, the frequency fre-quency of which will be Increased if inductance if reduced to the primary w inding or decreased if indu t.i:ic. jy added. A reduction in the capacity of a con-denser con-denser will likewise increase the frequency fre-quency of th. oscillations and an in-, in-, crease In capacity will reduce it. RADIO PRIM1 R SHORT CIRCUIT An Intentional or accidental connection by a con- Iductor across the terminals of an electric generator. A shortening of an electric circuit by touching of two j bare conductors In which the current i runs In opposite directions |