So far all I can find on the internet is that ethernet is at either 12.5 or 31.25mhz. NOT 350, that's gigE, not 10/100.
Also, this tower is a 100' wooden pole. Can't move anywhere really. marlon ----- Original Message ----- From: "Adam Goodman" <[email protected]> To: "WISPA General List" <[email protected]> Sent: Wednesday, January 07, 2009 9:15 AM Subject: Re: [WISPA] FM radio station site strangeness > It also sounds like there is a new leak in the waveguide. One more > thing you might try is to move the cable from leg to leg on the tower > so that you variable length sections that do not resonate at 350MHz or > ~100MHz (FM transminssion). > > > On Wed, Jan 7, 2009 at 11:16 AM, Adam Goodman <[email protected]> wrote: >> We also colocate with an FM transmitter. Only 1300W though. we also >> had interference on our Ethernet lines. We solved it by moving radios >> away from the FM antenna (3 feet or so on a 90' tower) We also >> installed ferrits which helped (I actually used a conduit pipe). >> Grounding the cat5 helped too. >> >> I would think that if you find that you need more shielding. put all >> your cat5 cables in a conduit and install abreakout box at the top of >> the tower. If your area is prone to electrical storms (where isn't >> these days?!) you will at some point be very sorry you didn't grount >> (and well!!) >> >> >> >> On Wed, Jan 7, 2009 at 10:47 AM, Marlon K. Schafer <[email protected]> >> wrote: >>> Hi All, >>> >>> I think we finally have this all figured out. Now I just have to figure >>> out >>> how to fix it. >>> >>> We've been up there for over 6 years now. It's certainly been a >>> problematic >>> site though. Constant channel changes (we have 3 competitors a mile >>> away >>> and pick up hundreds of ap's from in town) are the norm. >>> >>> This fall (a month or two ago) one of the tenants left the building. >>> This >>> cleared out most of the hardware that was in there. A little bit before >>> that I replaced an Inscape Data and a smartBridges combo with a single >>> MT >>> access point, using one of the cables that had been working for one of >>> the >>> other two. >>> >>> About a week ago things started to really act up. Multiple devices were >>> having trouble. I was able to catch it in the act finally. This time >>> the >>> problem wasn't a wireless issue, the devices were constantly >>> disconnecting >>> and reconnecting at the switch level. >>> >>> I pulled the Cisco switch out and dropped in a Netgear unit. That >>> didn't >>> fix it. Next I put in a Digital Loggers rack mount reboot device. That >>> wouldn't connect right either. >>> >>> I finally had to pull all of the hardware off of the shelf and set most >>> of >>> it on the floor (or just let it hang there) to get it working at all >>> well. >>> Still not perfect but better. >>> >>> I had by now hiked up there through sometimes knee deep snow 3 or 4 >>> times. >>> Next I took a motorbike with studded snow tires up and got permission to >>> turn down the power to the radio station. That didn't fix the problem >>> either. >>> >>> Next I borrowed a snowmobile and hauled some help and my spectrum >>> analyzer >>> up. I was unable to see any signals that didn't belong. >>> >>> Next day, another hike up the hill. >>> >>> OK, maybe a cat 5 cable went bad and I'm getting backfeed through the >>> switch. DC current or something. So I started testing the cables that >>> run >>> to the most problematic units. Well now, look at that. Bad cable. In >>> fact >>> there are three of them. Hmmm, kinda strange though. All three have >>> the >>> exact same fault! Oh well, better change them out anyway. I ran three >>> new >>> cable runs and just for kicks I tested one of them. What the heck????? >>> The >>> new cable has the EXACT same fault as the old one! Even though it >>> didn't >>> follow the exact same path as the old cables. >>> >>> Man, this is sure looking like a problem caused by the radio station. I >>> was >>> using indoor cat5 and didn't run lightning protection or ground >>> anything. >>> Yeah I know, but remember that this has been there for a very long time >>> like >>> this. And as a guy with an electrical background I know that there are >>> actually two ways to deal with stray electrical. Grounding is one. >>> Insulating is another!!!! Anyway, I know it wasn't built to specs. >>> >>> I added some grounding and that didn't help at all. >>> >>> Yesterday I finally had one of the local wireless companies (Day >>> Wireless) >>> that mainly does VHF radios, backhaul etc. They also checked things >>> with >>> the spectrum analyzer but couldn't find anything amiss. I was able to >>> duplicate the wiring fault for them (with my Ideal tester). But >>> suddenly >>> everything cleared right up! Stuff was looking good, no cable fault >>> etc. >>> Pings were looking good, devices were finally negotiating the >>> connections >>> right etc. >>> >>> I called the radio station to ask if I could try turning the power down >>> again to see if we see any change on the spectrum analyzer. They said >>> they >>> thought that I'd already done that because the showed the power was way >>> down. Turns out someone in the building had bumped a breaker and shut >>> down >>> part of the transmitter! Well, we got all of that figured out and guess >>> what. All of the problems came right back! I then turned the power >>> back >>> down and they cleared up. >>> >>> Tip for you guys, dropping an 18,000 watt system down by even 60% of >>> it's >>> normal output isn't always enough. We had to drop down to 10 to 20% to >>> get >>> the problems to clear up. The guys from Day Wireless had some small >>> ferrite >>> beads with them so we stuck them onto the cables. Put the beads on and >>> the >>> radios would negotiate at 100full. Take them off and they'd drop right >>> back >>> to 100 half. Duplicatable all day long. >>> >>> Soooo, current theory is that the radio station is screwing up my cat5 >>> connections. The fact that the building has less hardware in it and we >>> have >>> more snow up there than normal has probably caused some different eddy >>> currents or multipath. Or some other such strangeness. >>> >>> I have some shielded cable and connectors on the way. I have permission >>> to >>> move my gear from one side of the building to the other side. I've got >>> more >>> high end ferrite beads on the way (one that is made for cat 5 and is big >>> enough for three wraps to go through it). Not the little $.50 ones, >>> these >>> are nearly $6.00 each. >>> >>> I also have a Fluke DTX on the way. >>> http://www.flukenetworks.com/fnet/en-us/products/DTX+CableAnalyzer+Series/ >>> They rent for $650 per month from http://www.trs-rentelco.com/ List is >>> over >>> $7000. If I like it I'll probably get one and add it to my two spectrum >>> analyzers and my bucket truck. grin >>> >>> Never ever forget that wireless is 50% science and 62% black magic! >>> >>> I am quite hopeful that the new cable, beads on bother ends of the cat5, >>> better grounding, and an equipment move will fix this site up nicely. >>> If >>> not, who wants to buy it? lol Seriously, this site and one of the ones >>> that it feeds cause nearly 80% of my trouble calls. With any luck it >>> wasn't >>> wireless trouble that I've been having all along. Shrug. >>> >>> Here's the really strange part to all of this. The hardware that cost >>> the >>> most has the most trouble! grrrr >>> >>> Also, the Day Wireless guy had some kind of wide band sensor. He could >>> move >>> it around and see where overall signal levels were unsafe for people. >>> Right >>> beside a 4" or so copper pipe that the radio station used as a wave >>> guide >>> was pretty bad. A couple of inches from it was ok. The next highest >>> readings at the whole site? RIGHT a the BASE of the 100' wooden pole >>> that >>> everything is mounted on! And what did I do when I installed all this >>> new >>> gear a year ago? Yeah, I put the antennas up top and the radios right >>> down >>> at the base of the tower so I could get to them without having to rent a >>> lift. Dang the luck! >>> >>> Hope that this helps someone else out. >>> marlon >>> >>> >>> >>> >>> >>> -------------------------------------------------------------------------------- >>> 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! 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