transmitter, message, indication, directional antenna, sideband, beacons, frequencies, antenna, frequency modulation, beep, transceiver, freq, passband, indicator, analog, amplitude modulation, interferer, dipole antenna, millivolt, geophone, pulser, sensing, transponder, warning, readout, oscillator, inferior colliculus, annunciator, repeater, microvolt, hint, directional, metastability, transmissions, mux, demodulator, cherenkov radiation, lightwave, omen, chirp, vhf, radios, waveform, radiotelephone, uplink, trigger, homing device, morse code, telegraph, synchroniser, indictor, analogue, polarity, waveband, presage, amplitudes, quadrature, distress signal, pseudorandom, demultiplexer, amplifier, modulation, herald, voltage, transmitting, modem, intermodulation, resonant cavity, decoding, sign, photocell, baud rate, retrorocket, harbinger, exciter, radio frequency, cellular, variable resistor, circular polarization, milliwatt, omnidirectional antenna, circuitry, heterodyne, birdcall, wideband, ultrahigh frequency, impedances, dimming, directivity, reminder, drogue parachute, sensory neuron, phototransistor, dipole, sine wave, reactance, modulator, telemetry, decoder, jitter, nernst, photodiode, signals, input, waveforms, ap, non, outputs, stimulus, fig, module, thermal, vc, vector, dos, emf, i.e., incoming, intensities, dc, lowfrequency, wave, unmodulated, acoustic, circuit, d.c., audio, electric, highfrequency, microwave, volt, bioelectric, electrical, hydrological, measured, meteorological

alarm, alarum, alert, all clear, animal communication, augur, auspicate, beam, betoken, bode, bugle call, curfew, distress signal, dog-ear, drumbeat, electronic signal, flag, forecast, foreshadow, foretell, heliograph, high sign, indication, indicator, input, input signal, mark, number, omen, output, output signal, phone number, portend, predict, prefigure, presage, prognosticate, radiotelegraphic signal, radio beacon, radio beam, recording, retreat, semaphore, start, starting signal, storm signal, symbol, telegraphic signal, telephone number, ticktack, time signal, visual signal, warning signal, whistle, whistling, wigwag

., afp, air alert, alarm, alarum, alert, all clear, alpha fetoprotein, alpha foetoprotein, amplification, amplitude distortion, answer, attenuated, attenuator, audio, background noise, beacon, beam, beat, beckon, beep, bell, bengal light, bespeak, betoken, bleep, blinker, blinking, boosters, booster amplifier, booster stations, bugle call, burglar alarm, buzzer, call, carrier, carrier wave, closed circuit, crosstalk, curfew, delay line, demodulation, detection, detector, diaphone, distortion, distress call, distress signal, doorbell, doubler, drumbeat, electronic converter, electronic scanner, electronic signal, erasable, fadeout, fidelity, flag, flag down, flag of truce, flag stop, flasher, foghorn, fogsignal, frequency-response characteristic, frequency-response curve, frequency response, frown, fusee, fuzee, gain, generator, glower, go-ahead, green light, ground noise, gun, half-mast, heliograph, heterodyne oscillator, heterodyne receiver, high sign, imminent abortion, indicate, indicator, information, input, input signal, interrogate, kinescope, light, lights-out, local oscillator, loop, lour, lower, maroon, mayday, metal detector, mixer, modulation, nonlinear distortion, nyquist frequency, nyquist rate, output, output signal, overdrive, pick up, picture tube, point, prearranged, pulse modulation, quantise, quantize, quartz crystal, radar echo, radiotelegraphic signal, radio beacon, radio beam, rallying, recording, red flag, red light, relay links, relay stations, relay transmitters, remarkably, repeater, retreat, reveille, ring-a-rosy, ring-around-a-rosy, ring-around-the-rosy, round-trip light time, rtlt, s/n, sampling frequency, satellite television, satellite tv, scanner, secret, send a message, sensing element, sensor, signal-to-noise, signal-to-noise ratio, signal/noise, signal/noise ratio, signally, signal detection, signal fire, signal level, signal light, signify, siren, sleeper, sleeper nest, smile, sos, sound, squelch, squelcher, squelch circuit, start, starting signal, stoplight, storm signal, strength, strong, superhet, superheterodyne receiver, synchronous, system clock, taps, telegraphic signal, telegraph key, telephone bell, television tube, threatened abortion, time signal, traffic light, traffic signal, transponder, twilight zone, unmistakably, visual signal, wake-up signal, warning signal, watch fire, wave, way station, weak, whistle, whistle stop, white flag, wigwag, wink, xt, yellow light

communicate, communication, incitement, intercommunicate, provocation, tell

bespeak, betoken, impressive, indicate, point, sign, signaling, signalize