re: Novice questions on SW

HiTi,
Ham radio operators do not use FM below the 28-29.7 Mhz band. Most HF voice communications is conducted using single side band, either upper or lower (USB or LSB, respectively). Some fans of AM and historically interesting radios, continue to use that mode, but it is not widely used. On a technical level, FM refers to how the radio signal is modulated - and technically, one could modulate an FM signal anywhere. There are, however, some legal restrictions that would make its use unlikely or illegal in large parts of the spectrum.

The 3.5 to 4, 7, and 10 Mhz Amateur bands use primarily SSB, telegraph (CW), radio teletype, PSK31 (a newer form of radio teletype that is more efficient), and packet (data) radio communications.

I do not have the spurious emissions restrictions handy at the moment. But generally, spurious emissions outside the Amateur bands must be greatly suppressed.

Does anyone care about spurious emissions? They sure do. I once got a friendly note (really) from an FCC monitoring station that had picked up a spur from my transmitter; it was just an advisory suggesting that I look into it and did not require a reply. Currently, I am working with the local TV channel 2 in my town because they appear to have a spur within the Amateur 50 to 54 Mhz band. Other users of the spectrum are going to be protective of their allocations - so, generally, while the FCC might not be looking all the time, other users are looking at their own spectrum. Turning on a radio transmitter is the same as turning on a flashlight in a dark room - you will be found. Besides, it is good engineering practice to keep your spurs to the minimim possible.

Good luck,
Ed, KF7VY
Ham Radio Online