Audio-frequency amplifier, [185];
limitations of, [185]

Audion, [35], [40], [42]

Audion, amplifier, [182];
detector, theory of, [126];
modulator, [232];
oscillator, theory of, [89];
frequency control of, [99]

B-battery for tubes, [43];
effect upon characteristic, [128]

Banked wound coils, [228]

Battery, construction of gravity, [16];
dry, [27];
reversible or storage, [29]

Band of frequencies, [249]

Beat note, detection of, [221], [245]

Bell system, Arlington transmitter, [249]

Blocking of tube, reason for, [171]