In the case of grounding every 20-40 feet, what are you doing to achieve this without breaking down the water resistant jacket on the cable? Using an inline RJ45 POE surge protector? A ground tap clamp?
Also, in the case of Nanostations, the ground is done via the metal RJ45 STP connectors (the metal connector is the ground supposedly). Should I avoid hooking that STP ground up altogether? ----- Original Message ----- From: "Rick Harnish" <rharn...@greatamericanbroadband.com> To: "'WISPA General List'" <wireless@wispa.org> Sent: Saturday, January 03, 2009 4:16 PM Subject: Re: [WISPA] POE up AM radio tower > Doug, > > We have POE running on an identical AM tower (fairly low wattage) > configuration. We did used shielded cable and I believe we are grounding > the shield to the tower every 20-40' (can't remember). The shield does > pick > up the AM transmission and we also used ferrite beads at the bottom. Like > Jack says, it is extremely tricky to pull off and much care and patience > needs to happen in the engineering to ensure a workable solution. We do > have Canopy 5.2 running POE on this tower. > > Rick Harnish > > -----Original Message----- > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On > Behalf Of Jack Unger > Sent: Saturday, January 03, 2009 3:36 PM > To: WISPA General List > Subject: Re: [WISPA] POE up AM radio tower > > Doug, > > The only way to tell if using shielded cable would work is to try it. > Every high-power (radio tower) situation is unique. Most tower problems > occur on high-power FM towers where the FM frequency is close to the > Ethernet frequency but problems can easily exist on AM towers too > depending on AM transmit power levels, proximity to your cabling, > effectiveness of your shielding and grounding, filters internal to and > external from your equipment, etc. This topic (with examples) can be > discussed endlessly but each and every tower is going to be unique so if > you want a quick and correct answer then I'd suggest just going ahead > and trying it. Do your best on the initial shielding and grounding to > get the best result then see if that is good enough to meet your needs. > > jack > > Doug Ratcliffe wrote: >> We've had for many years access to a non-live AM radio tower (by >> non-live, > the antennas are mounted on the sides of the tower, insulated, look like > long steel cables). For a long time we ran AC to the top, into a small > choke/transformer (some little gizmo) that filtered the AM radio signal, > along with a fiber cable to the bottom. A lightning strike zapped all the > equipment a few years ago, and we never replaced it. The time has come > that > we need to put equipment on it again. >> >> I'd like to move towards running POE to the bottom, and at the top would > be Nanostations 2/5's. The tower is 160 ft tall self-supporting. I was > thinking about running shielded twisted pair cable. In the past we've > been > able to run short lengths of CAT5 at the top from the main power box, but > the last time any experimentation was done with CAT5 was with a former > partner, and the now deceased engineer that used to run the radio station. >> >> Would the shielded cable remove the interference/static charge/etc or is > this just not possible? >> >> >> > ---------------------------------------------------------------------------- > ---- >> WISPA Wants You! 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