After giving up at one of the towers which had lots of FM and AM and also Television equipment we moved to another tower which only had 2 FM stations, well things were ok and then after a week same problem started to appear, on Ethernet side we cannot go above 10mb, we are using STP cables with metal RJ-45 connectors, and earth both points, any further help ? as in this area there are no other towers which do not have FM stations on them. I have tried ever possibility here but failed to get 100mbps on the link.
You could always try using a fibre link up the tower and keeping the copper network cable as short as possible. If you are using PoE you will of course have to run a desperate power cable
Thats the last thing I want to try is the keep the equipment box up, and see if that helps, I would need to run power cable up as equipment are PoE. Will try and keep UTP as short as possible, but has this helped ?
I haven’t had to do this as we don’t put gear on towers with broadcast gear on them. One of my friends fixed the 10m problem with fibre - ran mains power up the tower and ran all the mast head equipment from a PoE switch using the ubiquity PoE converters.
In theory this will solve the problem. Never done it so cant confirm. The problem is the frequency that ethernet cable runs at is almost the same as FM radio hence the noise injected into the cable doing the damage.
I kept it last cause we had similar issue with other tower where we had equipment on top of tower and very short ethernet runs, and this problem surfaced, so we moved it down the tower and earthed all we could find, but the problem appeared with different radios, been fighting same issue with this tower again and again ! so we went with another less dense tower but again same story, so lets see if getting equipment up the tower can solve this one. thanks for input everyone. if i manage to solve i would report back here.
you must be shure WHERE inteference enters in your router.
you have 4 options: ethernet cable, antenna, radio case, power supply.
to debug an installation you must measure all these channels, using a spectrum analyzer.
The advice about a spectrum analyzer is solid. If you’re not that patient you might try putting ferrite toroids on every cable entering the router, including the power cord.
If i read this correctly you haver earthed both sides of the cat5/6 cables and would i be correct that the antenna is earthed on to the mast and the router is also earthed if this is done would it not create a earth loop, earthing should be to one point only (star earthing) i would suggest earthing only one end of the ethernet cable and not both end also maybe try if possible to remove the earthing on the antenna, I assume as this is a commercial mast there is a de-ioniser on the mast top.
In my experience no amount of earthing will completely stop the ingress of noise from a high power FM transmitter.
Also you must follow the advice of Roadie, Earthing both ends of your ethernet cable is very dangerous. If a potential difference occurs between both ends you can have a massive current flowing even to point of causing a fire.
I remember reading a post somewhere, The person found that earthing the cable actually made matters worse. I cannot clarify this as never tried it.
I have some antennas on a FM mast and was able to attenuate the noise just enough by using the best quality CAT6 and earthing the cable only at the bottom end directly into the ground with its own independant stake. Also check your cable run. make sure there is good distance from it and any FM RF cable over its entire run. If the FM Rf cable is poor quality or damaged it can leak noise all over your cables
Thanks a lot for all the responses, had been busy trying all methods to get away with noise, tried using non STP cables just to see if earthing made it worse, but we still see erros on ethernet side if we put any link above the 10mbps, the interference could be on device, wireless side, and cable. when the link is run at 10 it uses different freq and when run at 100 the frequency used is nearly to the FM one hence the interference, after doing lot of troubleshooting we found some radios worked better then other, the ones with metal cage then the ones with plastic, so we changed most of them to metal cases, and also the equipment box is metal and earthed, looks to be stable now, if the radios would support fiber i would change all to fiber ! and forget this problem
fiber is cheap you can use it on tower, and its durable too then ethernet cables, the only thing expensive is then to run DC up for the converters, and Radios, and splicing ! somebody asked running indoor fiber cable, its possible but jackets are not good for indoor cables, better to use armored, 50/30 meters don’t cost much and splicing remains same, be careful with sharp turns and you are good for future.
Old topic but may help someone for keeping it alive.
You say about 10Mbps Ethernet connection between the upper box (link) and the router/swicther inside the building/container!
Well…TRY to connect an OSBRIDGE Evolution 560 or similar to it and tell me IF you CAN at LEAST connect it at 10Mbps…
NO f(l)ucken way man!..NOT EVEN connected!..We put another cable, we put the cable away from the other RF transmiting cables, we shield it, we un-shieled it, we grounded both ends, we grounded each end at a time, we had ~35m of cable and at the end we had ~5m (below the linkbox) by bringing AC close to it, we got a BIG NOTHING with the OSBRIGDE link…BULL shi(f)t!..
I afterwards puted a Mikrotik one and BOOOOMMMM , 10MBps linkage locked.
After that, and a lot of experiments, I can now lock even at 1Gbps no matter what, with a LOT of hardware changings, which I will upload to this forum with photos anytime soon to help some guys out there.
Companies who build these things (Wi-Fi links) are NOT RF familiar (they don’t care) and they can’t encode/at least simulate somehow, what we RF guys encode on HIGH RF mountains with a LOT of FM radio stations, TV stations, and mobile stations/repeaters.
