Modes: Difference between revisions

Revision as of 22:15, 3 November 2023

This is a collection of the most common modes used in amateur radio.

A radio wave can be made to carry information such as sound, text, images or digital data, and a mode is a specific method for for encoding information on a radio wave, in this context known as the "carrier". A mode consists of a modulation and associated procedures.

The modulation is the specific way that the carrier wave is modified or "modulated" in order to encode information. The procedures are the rules that are agreed-upon by all users of a mode that ensures the information is universally understood and transferred successfully.

Analog modes

In analog modes, some property of the carrier wave is changed continuously in response to a continuously varying input. This is most commonly used to encode sound information, but can in principle encode nearly any type of information; analog modes exist to transfer images (facsimilie and SSTV) and video (analog television).

Analog modulation
Amplitude modulation (AM)	Single sideband (SSB)	Slow scan television (SSTV)

Digital modes

In digital modes, the carrier wave is only allowed to change between discrete states, called symbols. These symbols encode the information to be transferred, which is usually text but which can also include sounds, images, videos or other files.