Marshall-Gerken Co., Toledo, Ohio.

Michigan Paper Tube and Can Co., 2536 Grand River Ave., Detroit, Mich.

Murdock (Wm. J.) Co., Chelsea, Ma.s.s.

National Carbon Co., Inc., Long Island City, N. Y.

Pittsburgh Radio and Appliance Co., 112 Diamond St., Pittsburgh, Pa,

Radio Corporation of America, 233 Broadway, New York City.

Riley-Klotz Mfg. Co., 17-19 Mulberry St., Newark, N. J.

Radio Specialty Co., 96 Park Place, New York City.

Roller-Smith Co., 15 Barclay St., New York City.

Tuska (C. D.) Co., Hartford, Conn.

Western Electric Co., Chicago, Ill.

Westinghouse Electric Co., Pittsburgh, Pa.

Weston Electrical Instrument Co., 173 Weston Ave., Newark, N. J.

Westfield Machine Co., Westfield, Ma.s.s.

ABBREVIATIONS OF COMMON TERMS

A. ..............Aerial

A.C. ............Alternating Current

A.F. ............Audio Frequency

B. and S. .......Brown & Sharpe Wire Gauge

C. ..............Capacity or Capacitance

C.G.S. ..........Centimeter-Grain-Second

Cond. ...........Condenser

Coup. ...........Coupler

C.W. ............Continuous Waves

D.C. ............Direct Current

D.P.D.T. ........Double Point Double Throw

D.P.S.T. ........Double Point Single Throw

D.X. ............Distance

E. ..............Short for Electromotive Force (Volt)

E.M.F. ..........Electromotive Force

F. ..............Filament or Frequency

G. ..............Grid

Gnd. ............Ground

I. ..............Current Strength (Ampere)

I.C.W. ..........Interrupted Continuous Waves

KW. .............Kilowatt

L. ..............Inductance

L.C. ............Loose Coupler

Litz. ...........Litzendraht

Mfd. ............Microfarad

Neg. ............Negative

O.T. ............Oscillation Transformer

P. ..............Plate

Prim. ...........Primary

Pos. ............Positive

R. ..............Resistance

R.F. ............Radio Frequency

Sec. ............Secondary