Not yet. I've got some on the way thought. marlon ----- Original Message ----- From: <rea...@muddyfrogwater.us> To: "WISPA General List" <wireless@wispa.org> Sent: Wednesday, January 07, 2009 1:08 PM Subject: Re: [WISPA] FM radio station site strangeness
> Do you have the shielded cable? > > Mark > > > > ++++++++++++++++++++++++++++++++ > <insert witty tagline here> > > ----- Original Message ----- > From: "Marlon K. Schafer" <o...@odessaoffice.com> > To: "WISPA General List" <wireless@wispa.org> > Cc: <isp-wirel...@isp-wireless.com> > Sent: Wednesday, January 07, 2009 7:47 AM > Subject: [WISPA] FM radio station site strangeness > > >> 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! 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