The Radio Amateur's Hand Book / A Complete, Authentic and Informative Work on Wireless Telegraphy and Telephony

by A. Frederick Collins

RHEOSTAT, FILAMENT.--A variable resistance used for keeping the current of the storage battery which heats the filament of a vacuum tube at a constant voltage.

ROTATING COIL.--See Coil.

ROTARY GAP.--See Gap.

ROTOR.--The rotating coil of a variometer or a variocoupler.

RUHMKORFF COIL.--See Coil, Induction.

SATURATION.--The maximum plate current that a vacuum tube will take.

SENSITIVE SPOTS.--Spots on detector crystals that are sensitive to the action of electric oscillations.

SHORT WAVES.--See Waves.

SIDE WAVES.--See Wave Length Band.

SIGNALS, CONVENTIONAL.--(1) The International Morse alphabet and numeral code, punctuation marks, and a few important abbreviations used in wireless telegraphy. (2) Dot and dash signals for distress call, invitation to transmit, etc. Now used for all general public service wireless communication.