After some research, it looks like the actual range is 6770-7000. It seems like this band aligns with the "land mobile" band right under 40 meters. Are there any specific stations to watch out for here (other than 6903, 6913 and 6915)?
How about the "land mobile" designations above and below the 20 meter band (13.87-14MHz and 14.35-14.99MHz)? Is there anything to watch for there? Apparently the 20m band is the most popular during the day?
I plan on operating AM. What is the normal audio bandwidth for AM on shortwave. Is it the same as the broadcast band (10khz)? Can I use whatever I want? My transmitter can go up to 50khz, so I'm deciding where to filter the audio.
I know these may seem like obvious questions to some of you, but I am not a ham, and I'm new to shortwave. (I do have all the equipment (spectrum analyzer) to make sure I'm not putting out any harmonics or spurs, though.)
Thanks for all the help!
Under ITU rules, 4.5 KHz is considered 'standard' audio bandwidth (but there is no license to appease so who cares
). At the end of the day, most guys are listening with receivers that, SDR's withstanding, have limited audio bandwidth. Wider audio also disperses transmitter power across a much large range of frequencies and will be perceived as 'more open' and 'less dense' than using narrower bandwidth audio, but there's no free lunch; coverage and listenability often suffers. Wider receive bandwidth also lets more noise in, hampering reception of wide, weak signals.
In short, if your running DX and lots of power (over 250W carrier power) the North American NRSC-1 10 KHz modulation with pre-emphasis is a good way to go. For lower powers, 3-5 KHz is usually best. These are judgements made based on the airchecks I've received over the years from listeners, noting that most guys, even if wider bandwidth is available, will usually settle on 3-5 KHz. So most of the time, that lovely twinkerbell percussion in your favourite disco number is most like going to be enjoyed only by yourself on your modulation monitor
SDR's are changing this, and as they become more prevalent, I would guess more people will be enjoying better audio from our stations.
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