T8B: Concepts and types of modulation: CW, phone, RTTY and data emission types; FM deviation


AM, FM or SSB voice transmissions by radiotelephony are terms used for "phone transmissions".

Frequency-modulated phone is the name of the voice emission most used on VHF/UHF repeaters.

One thing you can you do if you are told your FM hand-held or mobile transceiver is over-deviating is to talk farther away from the microphone.

The part of a single-sideband signal that is above the carrier frequency is called the upper-sideband (USB).

The upper sideband is commonly used for 10-meter phone operation.


Data is the name used for packet-radio emissions.

Frequency-shift keying an RF signal is the usual way to produce an HF RTTY signal.

Two advantages to using modern data-transmission techniques for communications are high transmission speed and communications reliability.


Chirp describes a "problem" where a small change in a transmitter's frequency occurs each time it is keyed.