Re: Reality checks bouncing
In reply to #6666 reality checks bouncing by Leonard Erickson
[email removed] (Leonard Erickson) says: > .... Second, somewhere > between 20 and 100 MHZ, the signals quit bouncing off the ionosphere (if > the planet has one). At that point, range is *restricted* to > line-of-sight. Below it, you can reach whatever range you have the power > for. Oh yeah, the amount of interference has a *major* effect on > *usable* range. :-) Actually, it IS possilbe to get non-line-of-sight signals reliably through at frequencies around 4-5 GHz. The effect is known as troposcatter. The US Army uses this for medium range multi-channel radio shots. Typical ranges are in the 50 to 200 mile range. For up to around 50, the Army uses line-of-sight radios, and above this range, the Army uses satellites. It is very true that interference has a vast impact on ranges. Another factor influencing range is terrain. In Desert Storm, the Army discovered they could get longer ranges out of their line-of-sight radios than it was rated for when used over the sand. I do agree with you that for the radios listed, the power consumption is way too high. The highest power radio the Army uses is the Tropo radios. Those have a power consumption in the 1-2 kW range. All other radios are less than that. One of these days, when I get time and get settled in my new house, I'll try to organize some of the information I have on Army radios and send it out. - - David Paxson [email removed]