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��alternator shaft is a small direct current exciter. Engine and alternator are situated in a separate room from the rest of the apparatus. The engine is water- cooled by rain water collected in a large tank outside. The receiver consists of a Telefunken loosely coupled set with variable condensers, telephones, two sensitive Galena detectors and transfer switch. To the left of the receiver stand a high voltage tube condenser, the quenched, and variometer inductances. A hot-wire ammeter is included in the antenna circuit.

It is remarkable that this small station can work with Vera Cruz, over mountains and dry places, a distance of nearly 800 miles, but strange things hap- pen in the tropics.

��Pojpular Science Monthly

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��A Variable Condenser

VARLA-BLE condenser can be made of two test tubes covered out- side with tinfoil, one tube being a little smaller in diameter than the other. The smaller tube is placed inside of the large one, a flexible card being attached to the tinfoil on each. The condenser is varied by sliding the smaller tube in and out of the larger. There may be several sets of these condensers made and hooked up in either parallel or series. lor^e tube cohered m'fh fo// on oiyfj/de I

���Jmo// Me coi'ered iv/fh fo//on i

A variable condenser made from two test tubes

��Radio Club News

��THE Technical Association of Li- censed Operators, was formed on October 21. 1913. Meetings are held fortnightly, at which papers are presented and discussed. The present officers are : W. Woodrow, President ; E. T. Dickey, Secretary and Treasurer. Other clubs are invited to address communications to the secretary's of- fice, 1649 Amsterdam Ave.. New- York City.

Radio Club of Redlands

The Radio Ckil) of Redlands, Calif., was recently formed, with an initial membership of nine. The following officers were elected: President and Chief Operator. Ezra Moore ; Vice- President, Arthur Munzic ; Secretary- Treasurer, Rudolph Kubias, and Asst. Secretary-Treasurer. Harry William- son. Meetings are held every second Friday evening, at 7 :30 P. M.

Amateurs in nearby towns are re- quested to communicate with the club, at 108 Eleventh Street. Redlands, Cal.

Wireless Club in Salt Lake City

At a recent meeting officers were again elected to positions in the Granite Wire-

��less Association. The club is beginning its second year in amateur radio work and is now studying some of the latest works on Radio under the supervision of Prof. S. H. Besley. Most of the mem- bers have stations entirely of their own make and have secured excellent results. They hope to have the largest club of the Middle West and invite communica- tions from other clubs. These may be addressed to Pres. Merton Stevenson, Granite High School, Salt Lake City, Utah. The club's station call is G. W. A. and practice work is carried on the last Saturday evening in each month. Busi- ness meetings are held every Friday af- ternoon, beginning at 2 P. M. at the school building.

Pensacola Junior Radio Club

The Junior Radio Club of Pensacola, Ma., recently held its first meeting. The following officers were elected : Edwin Copas, President ; Oliver Williams. Sec- retary; Fred Gillmore. Operator. Near- by amateurs are invited to join. Ad- dress communications to PVed Gillmore. 127 W. Gregory Street, Pensacola, Fla.

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