On Mon, Feb 4, 2013 at 9:17 PM, Hal Murray <hmur...@megapathdsl.net> wrote: >
> Can you re-transmit on a nearby frequency without blasting the receiver off > the air? No not if it is in the same band, filters are never that good. I thought the OP had several bands available. So if this all needs to happen at one RF frequency the transmitter needs to act like a radar and send out modulated pulses. The oscilator that does the modulation (sawtooth?) needs to run continuously. so that the phase of the returned signal can be compared. If you don't know the range you need a conservative pulse repetition frequency (PRF in Radar speak) then once you find the range you can use a faster one to collect better data if you need to. The fester PRF transmits on average more energy so you get better data The advantage is that all the "smarts" is in just one place, all the other units are simply a "mirror with gain" or "bent pipe". The next level of sophistication is to scan the antenna and note the azimuth position when the signal is maximum. Then you have both range and diction. No need to triangulate. Radars sound expensive but go to any small boat marina and you see that even small boats have them. The newels units integate with GPS and the boats auto pilot and still prices at retail level are under $2K for entry level systems. All that said, why not simply use GPS? Your mobile unit can have a GPS receiver and transmit is location. This works ten times better and cost a lot less. The cell phone industry gave up on triangulation when GPS because cheap and easy -- Chris Albertson Redondo Beach, California _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.