>How do they propose to syncronize the frequency hopping algorithm when
>using SS in casual QSO's. For that matter how does one know which to use.

One way it is done involves running the "pseudorandom" spredaing code in the receiver slightly fast or slow. Eventually the signals will syncronize; then the receiver runs through the code at the standard rate. And if the syncronization is lost, the process repeats itself.

The code used would have to be agreed upon before the contact is attempted; instead of using a calling frequency, for example, a calling code would be used. Then, after establishing a contact, the stations could go to a discreet code in a manner similar to non-SS stations going to a discreet frequency to pass traffic or ragchew.

I've been told that the military has used GPS signals for generating codes and also syncing the radios. The spreading code then depends on when the transmission takes place, and it doesn't repeat. You can hear some of these signals between about 255 and 270 MHZ in the military satellite downlink band. The frequency hoppers sound like the old Russian Woodpecker. Direct sequence spread spectrum radios put out a more subtle "white noise with meaning" that I have not been able to distinguish from the background noise.

Regards, Phil Collier, KG2DH

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