Filtering is pretty moot when you consider they are in plastic housings with no significant shielding.... :-)
-B- On 12/20/2010 6:31 PM, Leon D. Zetekoff wrote: > 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 is 100% correct. Remember these radios do not have much filtering > in the front-ends so you have to make up for it with external accessories. > > Leon >> 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: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > > -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
