Re: [WISPA] High Power RF close-proximity on tower question
Ouch. I can just feel the flesh boiling. Probably have to wear a radiation suite to work on your radio, being that close to that. I'd predict the Ubiquitits would get severe receiver overload without filters added. Any chance of moving your antennas further away? Or the FM antennas further away? Dont you have a non-interference clause? I'd think that would protect against receive overload also. Can you put the expense on the FM antenna guy, to buy your filters, since you were there first? Tom DeReggi RapidDSL Wireless, Inc IntAirNet- Fixed Wireless Broadband - Original Message - From: Scott Carullo To: wireless@wispa.org Sent: Monday, December 20, 2010 4:30 PM Subject: [WISPA] High Power RF close-proximity on tower question 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 -- 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/ 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/
Re: [WISPA] High Power RF close-proximity on tower question
What gear are you running? 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 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/ -- Jack Unger - President, Ask-Wi.Com, Inc. Author - "Deploying License-Free Wireless Wide-Area Networks" Serving the WISP, Networking and Telecom Communities since 1993 www.ask-wi.com 818-227-4220 jun...@ask-wi.com 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/
Re: [WISPA] High Power RF close-proximity on tower question
2 Trango 11Ghz Apex's 3 Ubiquiti Rocket M5 sectors 3 Ubiquiti Rocket M2 sectors 1 Nanostation M5 3 Rocket M5s with 34db dishes 2 Radwin 2000C's Scott Carullo Technical Operations 855-FLSPEED x102 From: Jack Unger jun...@ask-wi.com Sent: Monday, December 20, 2010 4:47 PM To: sc...@brevardwireless.com, WISPA General List wireless@wispa.org Subject: Re: [WISPA] High Power RF close-proximity on tower question What gear are you running? 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 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/ -- Jack Unger - President, Ask-Wi.Com, Inc. Author - Deploying License-Free Wireless Wide-Area Networks Serving the WISP, Networking and Telecom Communities since 1993 www.ask-wi.com 818-227-4220 jun...@ask-wi.com 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/
Re: [WISPA] High Power RF close-proximity on tower question
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/
Re: [WISPA] High Power RF close-proximity on tower question
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/ -- Jack Unger - President, Ask-Wi.Com, Inc. Author - Deploying License-Free Wireless Wide-Area Networks Serving the WISP, Networking and Telecom Communities since 1993 www.ask-wi.com 818-227-4220 jun...@ask-wi.com 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/
Re: [WISPA] High Power RF close-proximity on tower question
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/ 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/
Re: [WISPA] High Power RF close-proximity on tower question
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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] High Power RF close-proximity on tower question
I have an fm antenna (low power) on the tower where I am at at about 35 feet above me and I have a CPE on an FM backup antenna with no problems. This is Axxcelera 3.65 wimax. Shielded cable with good grounds. No need for ferrite beads so far. Sent from my iPhone4 On Dec 20, 2010, at 5:31 PM, Leon D. Zetekoff wa4...@backwoodswireless.net 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: wireless@wispa.org 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] High Power RF close-proximity on tower question
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: wireless@wispa.org 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] High Power RF close-proximity on tower question
Yeah, external filters are not an option for me. They are going to work or... The Trango and Radwin equipment may have a chance. I'm not really giving the UBNT stuff a chance at all. Am I being too pessimistic? Its the ethernet I've had the most problems with in the past, not the radios receivers Scott Carullo Technical Operations 855-FLSPEED x102 From: Bob Moldashel lakel...@gbcx.net Sent: Monday, December 20, 2010 6:39 PM To: wa4...@arrl.net, WISPA General List wireless@wispa.org Subject: Re: [WISPA] High Power RF close-proximity on tower question 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: wireless@wispa.org 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: wireless@wispa.org 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: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
