Frequency Modulation - Revision history

Jnc: Clarify

2026-10-15T11:55:01Z

Clarify

← Older revision		Revision as of 11:55, 15 October 2026
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	'''Frequency Modulation''' (or '''FM''') is an encoding technique, used for the encoding of both [[analog]] and [[digital]] data.		'''Frequency Modulation''' (or '''FM''') is an encoding technique, used for the encoding of both [[analog]] and [[digital]] data.

	For analog data, it typically takes a 'carrier' signal, at a fixed [[frequency]], and varies that frequency slightly, based on the analog [[signal]] to be encoded. This was the form used in 'FM radio' (hence that name).		For analog data, it typically takes a 'carrier' signal, at a fixed [[frequency]], and varies that frequency of that signal slightly, based on the analog [[signal]] to be encoded. This was the form used in 'FM radio' (hence that name).

	The form used for digital data is used in [[magnetic storage]], such as [[disk]]s and [[Disk#Low-cost disks\|floppy drive]]s.		The form used for digital data is used in [[magnetic storage]], such as [[disk]]s and [[Disk#Low-cost disks\|floppy drive]]s.

Jnc: Add original, analog definition

2026-09-23T00:15:53Z

Add original, analog definition

← Older revision		Revision as of 00:15, 23 September 2026
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	'''Frequency Modulation''' (or '''FM''') is an encoding technique, used in [[~~magnetic storage~~]] ~~such as [[disk]]s~~ and [[~~Disk#Low-cost disks\|floppy drive~~]]s.		'''Frequency Modulation''' (or '''FM''') is an encoding technique, used for the encoding of both [[analog]] and [[digital]] data.

	In FM there is a reversal (signal level, or magnetic flux) at the start of every data bit time (i.e. every clock time); for a '1', there is an additional reversal in the middle of the bit time, with no reversal indicating a '0'.		For analog data, it typically takes a 'carrier' signal, at a fixed [[frequency]], and varies that frequency slightly, based on the analog [[signal]] to be encoded. This was the form used in 'FM radio' (hence that name).

			The form used for digital data is used in [[magnetic storage]], such as [[disk]]s and [[Disk#Low-cost disks\|floppy drive]]s.

			==FM for magnetic media==

			In digital FM, there is a reversal (signal level, or magnetic flux) at the start of every data [[bit]] time (i.e. every [[clock]] time); for a '1', there is an additional reversal in the middle of the bit time, with no reversal indicating a '0'.

	Consecutive zeros show a reversal between data bit times; consecutive ones show two reversals in every bit time (i.e. doubling the frequency of reversals; hence the name).		Consecutive zeros show a reversal between data bit times; consecutive ones show two reversals in every bit time (i.e. doubling the frequency of reversals; hence the name).

Jnc: +cat

2018-12-14T19:21:13Z

+cat

← Older revision		Revision as of 19:21, 14 December 2018
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	{{semi-stub}}		{{semi-stub}}

			[[Category: Theory]]

Jnc: Proper cat

2018-10-18T19:54:21Z

Proper cat

← Older revision		Revision as of 19:54, 18 October 2018
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	It was mostly replaced by [[Modified Frequency Modulation]], which can store twice as many bits in the same maximum reversal rate.		It was mostly replaced by [[Modified Frequency Modulation]], which can store twice as many bits in the same maximum reversal rate.

	{{stub}}		{{semi-stub}}

Jnc: Slightly clarify

2017-10-25T15:34:10Z

Slightly clarify

← Older revision		Revision as of 15:34, 25 October 2017
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	'''Frequency Modulation''' (or '''FM''') is an encoding technique, used in [[magnetic storage]] such as [[disk]]s and [[Disk#Low-cost disks\|floppy drive]]s.		'''Frequency Modulation''' (or '''FM''') is an encoding technique, used in [[magnetic storage]] such as [[disk]]s and [[Disk#Low-cost disks\|floppy drive]]s.

	In FM there is a reversal (signal level, or magnetic flux) at the start of every data bit time; for a '1', there is an additional reversal in the middle of the bit time, with no reversal indicating a '0'.		In FM there is a reversal (signal level, or magnetic flux) at the start of every data bit time (i.e. every clock time); for a '1', there is an additional reversal in the middle of the bit time, with no reversal indicating a '0'.

	Consecutive zeros show a reversal between data bit times; consecutive ones show two reversals in every bit time (i.e. doubling the frequency of reversals; hence the name).		Consecutive zeros show a reversal between data bit times; consecutive ones show two reversals in every bit time (i.e. doubling the frequency of reversals; hence the name).

Jnc: An OK start

2017-10-25T14:42:08Z

An OK start

New page

'''Frequency Modulation''' (or '''FM''') is an encoding technique, used in [[magnetic storage]] such as [[disk]]s and [[Disk#Low-cost disks|floppy drive]]s.

In FM there is a reversal (signal level, or magnetic flux) at the start of every data bit time; for a '1', there is an additional reversal in the middle of the bit time, with no reversal indicating a '0'.

Consecutive zeros show a reversal between data bit times; consecutive ones show two reversals in every bit time (i.e. doubling the frequency of reversals; hence the name).

It was mostly replaced by [[Modified Frequency Modulation]], which can store twice as many bits in the same maximum reversal rate.

{{stub}}