) writes:
How can I possibly send an SOS message transmitted in a short range
signal having a normal computer modem ,a computer and a radio ,or just
transmitting in morse signal . How can I do it .

You don't.

The only reason you'd send an SOS is because you were actually in
an emergency situation, and SOS is actually specified for a certain
level of emergency (ie you can't use it if your car breaks down).

ONce you start messing with sending SOS for any reason, you risk
causing a situation, where effort will be put into finding you, only
to discover there is no emergency.

Michael VE2BVW