must not /> >/exceed 56 kilobauds. A RTTY, data or multiplexed emission using an unspecified /> >/digital code under the limitations listed in ?97.309(b) of this part also may /> >/be transmitted. The authorized bandwidth is 100 kHz. / The Trailblazer was fast, but it wasn't *that* fast! It actually was like 19200 baud async, internally some 18kbps sync. This was fast compared to the usual V.22bis (2400 bps) modems of the day, but of course later telephone modems appeared that could to 56k. We ran a Unix system with UUCP at work in those days but we could not use modems that fast because the machine wasn't able to handle full 19200 baud async I/O as it could not handle the interrupt load... those were the days. (It was an NCR system with a separate processor for serial I/O, but IBM PC and clones in those days also struggled at 19200, that is why the 16550 chip with hardware FIFO was created...) A couple of years later I bought a ZyXEL U-1496+ modem that also did 19200 over phone lines, and was popular at some local ISPs. Like the Trailblazer it also used a 68000 processor and it cost well over $500 in local currency. I agree that those modems are not going to work over radio. Even on telephone lines they perform lengthy "training" sequences to measure the phase response of the line, and then assume it remains the same over the duration of the call. Rob