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

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"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