Another item to consider is that there are significant effects which the atmosphere has upon these very high frequencies. For example, water vapor and oxygen have strong absorption bands (I think 22GHz and 40GHz, respectively). Also, water droplets in rain, clouds, and fog can scatter microwaves much more than lower frequencies. For these reasons, the use of much of this very high frequency territory is limited to special applications. On Sun, Apr 25, 2010 at 5:48 PM, solarwind wrote: > I've been looking at the Radio Amateurs of Canada band plans here: > http://www.rac.ca/en/rac/services/bandplans/allband.php and I see them > listing the 5 GHz - 248 GHz. Do people actually use these bands? > What's the highest frequency that a radio amateur can practically use? > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist