True...good advice. On 12/20/2010 05:56 PM, Jack Unger wrote: > There is QUITE a difference between a separation distance of 20 ft and a > separation distance of 100 yards. Remember the inverse-square law - RF > intensity > decreases as the SQUARE of the separation distance. 100 yards is 300 feet and > 20 > feet goes into 300 feet 15 times so the RF intensity at 100 yards is the > inverse > of 15 squared (15X15) or the inverse of 225. Inverting 225 means that the > intensity at 100 yards is only 1/225th as much as at 20 feet. Scott's > equipment > is going to be exposed to 225 times greater RF energy than yours so his > equipment is likely to be overloaded with receiver de-sensitization while your > equipment may be OK. > > The solution is to "do everything right" as Scott says. The 11 GHz equipment > is > likely so far away from the FM and TV frequencies that it is probably OK. The > solution for 2.4 and 5 GHz is use proper bandpass filters between the antennas > and the equipment then test to see if the receivers seem to have full > sensitivity or not. > > jack > > > On 12/20/2010 2:34 PM, Bret Clark wrote: > >>> On 12/20/2010 1:30 PM, Scott Carullo wrote: >>> >>>> Ok, I've dealt with up to about 20KW on FM transmitter 20 feet away >>>> and dealt with it decently. >>>> >>>> Now I'm told one of our installs of gear on a tower is about to get a >>>> 100KW 20ft above my gear and a TV antenna 20ft below it at 700KW >>>> channel 39 I think. >>>> >>>> Anyone have gear running close to this kind of high-power antennas? >>>> Am I screwed or will I be able to have my equipment work int his RF >>>> environment? Assume I did everything right (grounded metal box, >>>> shielded cable soldered drain wires, ferrite cores on the cables etc...). >>>> >>>> Thanks >>>> >>>> Scott Carullo >>>> Technical Operations >>>> 855-FLSPEED x102 >>>> >> We are running 5.8 and 3.65 stuff on towers with 100KW TV systems on the >> tower located about a 100 yards from us on another tower...no problems. >> Probably not much difference between 100KW 20 feet or 100 yards apart. >> >> >> >> -------------------------------------------------------------------------------- >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> -------------------------------------------------------------------------------- >> >> WISPA Wireless List: wireless@wispa.org >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ >> >> >> >
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