On Sun, 13 Mar 2005 19:32:17 -0500, "Dee Flint"
wrote:


also, when people refer to ASK and FSK, is ASK basically an audio
output that's been sent over FM? and FSK is more like CW, only to a
receiver that can monitor both mark and space (0 and 1) frequencies?

always thought amplitude-shift-keying was mainly used for morse

I believe he meant AFSK (audio frequency shift keying) vs FSK (frequency
shift keying).

The ITU emission designators for some digital modes and some typical
usage:

* A1A On/Off keying for manual reception (Morse)

* A1D ASK, Amplitude shift keying. The only recent use I have seen
is in some 433 MHz SRD (Short Range Devices)

* F1D Pure FSK (RTTY is classified as F1B)

* F2D Audio subcarrier modulated by amplitude or frequency (e.g.
1200 bit/s AX.25 packet) modulating an FM transmitter

* A2A Audio subcarrier on/off modulated by Morse code modulating
an AM transmitter (e.g. aeronautical beacons in the LF band)

* A2D Audio subcarrier modulated by amplitude or frequency
modulating an AM transmitter

* J2A Audio subcarrier on/off modulated by Morse code modulating
an SSB transmitter (many amateur multimode rigs)

* J2D Audio subcarrier modulated by amplitude or frequency (e.g.
300 bit/s AX.25 packet) modulating an SSB transmitter

On the air A1A and J2A are equivalent.

On the air F1D and J2A are equivalent and can be generated and
detected in both ways.

I hope this clarifies some of the issues.

Paul OH3LWR