From URL:

http://www.tpub.com/content/neets/14...s/14184_94.htm

FSK SIGNALS.-In fsk the rf signal is shifted in frequency (not amplitude)
between "key-open" and "key-closed" conditions. The signal amplitude remains
essentially constant. View (A) of figure 2-3 represents the letter "F" keyed
as a shift in frequency between mark and space. The normal frequency
condition with the key open is a space. Recall that this may be either the
lower or higher frequency. When the key is closed, the frequency instantly
changes to the mark value and remains constant during the marking interval.
Opening the key again returns the frequency to the space frequency. Midway
between the mark and space frequencies is the assigned channel frequency

AFSK signals are at URL:

http://www.ik3qar.it/rtty/3/
--
73 From The Signal In The Noise
Caveat Lector Ya All

------------------------------------------------------------

"TeeAye" wrote in message
...
On 9 Sep 2003 14:07:15 GMT, "Dick Carroll;" wrote:

For amateur radio, the frequency is considered to be that of the MARK
signal.

Also known as the "resting frequency", IIRC

Dick

__________________________________________________ _______

New one on me.

--
Bill, W7TI

On Tue, 9 Sep 2003 08:40:41 -0700, "Caveat Lector"
wrote:

From URL:

http://www.tpub.com/content/neets/14...s/14184_94.htm

FSK SIGNALS.-In fsk the rf signal is shifted in frequency (not amplitude)
between "key-open" and "key-closed" conditions. The signal amplitude remains
essentially constant. View (A) of figure 2-3 represents the letter "F" keyed
as a shift in frequency between mark and space. The normal frequency
condition with the key open is a space. Recall that this may be either the
lower or higher frequency. When the key is closed, the frequency instantly
changes to the mark value and remains constant during the marking interval.
Opening the key again returns the frequency to the space frequency. Midway
between the mark and space frequencies is the assigned channel frequency

AFSK signals are at URL:

http://www.ik3qar.it/rtty/3/
--
73 From The Signal In The Noise
Caveat Lector Ya All

Damn, I thought I had received a definitave answer, and now I get a
contrary view... ;-(
goes away muttering untypeable utterances....

On Tue, 9 Sep 2003 08:40:41 -0700, "Caveat Lector"
wrote:

From URL:

http://www.tpub.com/content/neets/14...s/14184_94.htm

FSK SIGNALS.-In fsk the rf signal is shifted in frequency (not amplitude)
between "key-open" and "key-closed" conditions. The signal amplitude remains
essentially constant. View (A) of figure 2-3 represents the letter "F" keyed
as a shift in frequency between mark and space. The normal frequency
condition with the key open is a space. Recall that this may be either the
lower or higher frequency. When the key is closed, the frequency instantly
changes to the mark value and remains constant during the marking interval.
Opening the key again returns the frequency to the space frequency. Midway
between the mark and space frequencies is the assigned channel frequency

AFSK signals are at URL:

http://www.ik3qar.it/rtty/3/
--
73 From The Signal In The Noise
Caveat Lector Ya All

Damn, I thought I had received a definitave answer, and now I get a
contrary view... ;-(
goes away muttering untypeable utterances....

Ok lets simplifies it
From URL:
http://wombat.doc.ic.ac.uk/foldoc/fo...y+Shift+Keying

communications (FSK) The use of frequency modulation to transmit digital
data, i.e. two different carrier frequencies are used to represent zero and
one.

FSK was originally used to transmit teleprinter messages by radio (RTTY) but
can be used for most other types of radio and land-line digital telegraphy.
More than two frequencies can be used to increase transmission rates.

Also URL: http://www.its.bldrdoc.gov/fs-1037/dir-016/_2347.htm

frequency-shift keying (FSK): Frequency modulation in which the modulating
signal shifts the output frequency between predetermined values. (188) Note
1: Usually, the instantaneous frequency is shifted between two discrete
values termed the "mark" and "space" frequencies. This is a noncoherent form
of FSK. Note 2: Coherent forms of FSK exist in which there is no phase
discontinuity in the output signal. Synonyms frequency-shift modulation,
frequency-shift signaling.

Also see URL:
http://searchnetworking.techtarget.c...213936,00.html

Frequency-shift keying (FSK) is a method of transmitting digital signals.
The two binary states, logic 0 (low) and 1 (high), are each represented by
an analog waveform. Logic 0 is represented by a wave at a specific
frequency, and logic 1 is represented by a wave at a different frequency. A
modem converts the binary data from a computer to FSK for transmission over
telephone lines, cables, optical fiber, or wireless media. The modem also
converts incoming FSK signals to digital low and high states, which the
computer can "understand."


--
73 From The Signal In The Noise
Caveat Lector Ya All
---------------------------------------------------
"Mike W" wrote in message
...
On Tue, 9 Sep 2003 08:40:41 -0700, "Caveat Lector"
wrote:

From URL:

http://www.tpub.com/content/neets/14...s/14184_94.htm

FSK SIGNALS.-In fsk the rf signal is shifted in frequency (not amplitude)
between "key-open" and "key-closed" conditions. The signal amplitude
remains
essentially constant. View (A) of figure 2-3 represents the letter "F"
keyed
as a shift in frequency between mark and space. The normal frequency
condition with the key open is a space. Recall that this may be either
the
lower or higher frequency. When the key is closed, the frequency
instantly
changes to the mark value and remains constant during the marking
interval.
Opening the key again returns the frequency to the space frequency.
Midway
between the mark and space frequencies is the assigned channel frequency

AFSK signals are at URL:

http://www.ik3qar.it/rtty/3/
--
73 From The Signal In The Noise
Caveat Lector Ya All

Damn, I thought I had received a definitave answer, and now I get a
contrary view... ;-(
goes away muttering untypeable utterances....

Ok lets simplifies it
From URL:
http://wombat.doc.ic.ac.uk/foldoc/fo...y+Shift+Keying

communications (FSK) The use of frequency modulation to transmit digital
data, i.e. two different carrier frequencies are used to represent zero and
one.

FSK was originally used to transmit teleprinter messages by radio (RTTY) but
can be used for most other types of radio and land-line digital telegraphy.
More than two frequencies can be used to increase transmission rates.

Also URL: http://www.its.bldrdoc.gov/fs-1037/dir-016/_2347.htm

frequency-shift keying (FSK): Frequency modulation in which the modulating
signal shifts the output frequency between predetermined values. (188) Note
1: Usually, the instantaneous frequency is shifted between two discrete
values termed the "mark" and "space" frequencies. This is a noncoherent form
of FSK. Note 2: Coherent forms of FSK exist in which there is no phase
discontinuity in the output signal. Synonyms frequency-shift modulation,
frequency-shift signaling.

Also see URL:
http://searchnetworking.techtarget.c...213936,00.html

Frequency-shift keying (FSK) is a method of transmitting digital signals.
The two binary states, logic 0 (low) and 1 (high), are each represented by
an analog waveform. Logic 0 is represented by a wave at a specific
frequency, and logic 1 is represented by a wave at a different frequency. A
modem converts the binary data from a computer to FSK for transmission over
telephone lines, cables, optical fiber, or wireless media. The modem also
converts incoming FSK signals to digital low and high states, which the
computer can "understand."


--
73 From The Signal In The Noise
Caveat Lector Ya All
---------------------------------------------------
"Mike W" wrote in message
...
On Tue, 9 Sep 2003 08:40:41 -0700, "Caveat Lector"
wrote:

From URL:

http://www.tpub.com/content/neets/14...s/14184_94.htm

FSK SIGNALS.-In fsk the rf signal is shifted in frequency (not amplitude)
between "key-open" and "key-closed" conditions. The signal amplitude
remains
essentially constant. View (A) of figure 2-3 represents the letter "F"
keyed
as a shift in frequency between mark and space. The normal frequency
condition with the key open is a space. Recall that this may be either
the
lower or higher frequency. When the key is closed, the frequency
instantly
changes to the mark value and remains constant during the marking
interval.
Opening the key again returns the frequency to the space frequency.
Midway
between the mark and space frequencies is the assigned channel frequency

AFSK signals are at URL:

http://www.ik3qar.it/rtty/3/
--
73 From The Signal In The Noise
Caveat Lector Ya All

Damn, I thought I had received a definitave answer, and now I get a
contrary view... ;-(
goes away muttering untypeable utterances....

On Tue, 9 Sep 2003 14:24:43 -0700, "Caveat Lector"
wrote:

Ok lets simplifies it

No need I've been sending and receiving RTTY for years so I know what
FSK and AFSK is and what it sounds like.
The question was..
Which frequency is the carrier frequency as regards HF and VHF
Beacons, and I suppose A/FSK data, in the Amateur service.
The Mark, the Space or in the middle for Amateur usage ( the frequency
you log in your logbook ).
Keying can be normal or inverted making the space either higher or
lower than the mark so saying that the mark is the carrier frequency..
occasionally.. is'nt much use is it ?.

On Tue, 9 Sep 2003 14:24:43 -0700, "Caveat Lector"
wrote:

Ok lets simplifies it

No need I've been sending and receiving RTTY for years so I know what
FSK and AFSK is and what it sounds like.
The question was..
Which frequency is the carrier frequency as regards HF and VHF
Beacons, and I suppose A/FSK data, in the Amateur service.
The Mark, the Space or in the middle for Amateur usage ( the frequency
you log in your logbook ).
Keying can be normal or inverted making the space either higher or
lower than the mark so saying that the mark is the carrier frequency..
occasionally.. is'nt much use is it ?.

Does this URL help
http://www.ref-union.org/thf/9aa2.pdf

--
73 From The Signal In The Noise
Caveat Lector Ya All
"Mike W" wrote in message
...
On Tue, 9 Sep 2003 14:24:43 -0700, "Caveat Lector"
wrote:

Ok lets simplifies it

No need I've been sending and receiving RTTY for years so I know what
FSK and AFSK is and what it sounds like.
The question was..
Which frequency is the carrier frequency as regards HF and VHF
Beacons, and I suppose A/FSK data, in the Amateur service.
The Mark, the Space or in the middle for Amateur usage ( the frequency
you log in your logbook ).
Keying can be normal or inverted making the space either higher or
lower than the mark so saying that the mark is the carrier frequency..
occasionally.. is'nt much use is it ?.

Does this URL help
http://www.ref-union.org/thf/9aa2.pdf

--
73 From The Signal In The Noise
Caveat Lector Ya All
"Mike W" wrote in message
...
On Tue, 9 Sep 2003 14:24:43 -0700, "Caveat Lector"
wrote:

Ok lets simplifies it

No need I've been sending and receiving RTTY for years so I know what
FSK and AFSK is and what it sounds like.
The question was..
Which frequency is the carrier frequency as regards HF and VHF
Beacons, and I suppose A/FSK data, in the Amateur service.
The Mark, the Space or in the middle for Amateur usage ( the frequency
you log in your logbook ).
Keying can be normal or inverted making the space either higher or
lower than the mark so saying that the mark is the carrier frequency..
occasionally.. is'nt much use is it ?.

I believe it is pretty much standard that the Mark is the lower RF
frequency. For AFSK using a SSB transmitter that means that the audio
Mark tone is the higher frequency and the transmitter is set to LSB
which inverts it to the lower RF frequency.

For amateur and most commercial operation, the RF Mark frequency is
generally given as the assigned frequency. The military uses the
center, half way between Mark and Space as the assigned frequency.
Because they assign channel frequencies as the center of the assigned
bandwidth, this always puts the FSK signal in the center of the
channel.