I had a chance to get up to the tower again this afternoon and play around. There is nearly 200% of the legal limit of exposure of RF on the cat five cable.
It seems to make no difference whether I lift the ground ground the ground or do anything with the ground, the negotiation issues are still there. Perhaps using something like superior Essex might help, but it also might be a crapshoot that does nothing. > On Apr 24, 2019, at 2:51 PM, Bill Prince <[email protected]> wrote: > > This was in the days when we had to run a separate cable for timing (and > those signals we single-ended; not differential). The timing cable ran > parallel to the cat 5, and the APs were losing sync intermittently. The > power/ground inside the CMM was going crazy to the tune of 8-12 volts or > something like that. > > We added bigger grounds to the power supply and CMM, and when we got to 4 AWG > it actually got worse. > > > bp > <part15sbs{at}gmail{dot}com> > >> On 4/24/2019 11:19 AM, Matt Hoppes wrote: >> Interesting, so possibly the issue is occurring through the >> grounding/electoral system. >> >>> On Apr 24, 2019, at 1:47 PM, Bill Prince <[email protected]> wrote: >>> >>> It wasn't actually on the cat5, it was on the ground (and indirectly the >>> power supply). This when we were using the old-style Canopy timing box >>> (CMM? not sure of the name any more). >>> >>> We had to ground isolate the scope to prevent it from being infected as >>> well. >>> >>> >>> bp >>> <part15sbs{at}gmail{dot}com> >>> >>>> On 4/24/2019 10:31 AM, Matt Hoppes wrote: >>>> How did you “look at it” on the CAT5? >>>> >>>>> On Apr 24, 2019, at 1:28 PM, Bill Prince <[email protected]> wrote: >>>>> >>>>> Back when we were getting interference like this (around 12-13 years >>>>> ago), the noise was actually intermod from a couple of nearby high power >>>>> transmitters. We didn't see it until we were able to look at it with a >>>>> high frequency oscilloscope. >>>>> >>>>> It would come and go based on whether both of those transmitters were >>>>> operating at the same time. >>>>> >>>>> >>>>> bp >>>>> <part15sbs{at}gmail{dot}com> >>>>> >>>>>> On 4/24/2019 9:36 AM, Matt Hoppes wrote: >>>>>> If I take a volt meter and measure from ground wire/rack to earth >>>>>> ground. Would I see voltage if the transmitter is getting in at any >>>>>> significant amount? >>>>>> >>>>>>> On Apr 24, 2019, at 12:25 PM, Robert Andrews <[email protected]> >>>>>>> wrote: >>>>>>> >>>>>>> & if the noise is coming from the grounding point? >>>>>>> >>>>>>>> On 04/24/2019 09:01 AM, [email protected] wrote: >>>>>>>> If you let shields float, they are a faraday shield. >>>>>>>> If you ground one end of the shields, they are faraday plus >>>>>>>> electrostatic shielding. >>>>>>>> If you ground both ends of the shields they do all of that but they >>>>>>>> also add magnetic shielding. >>>>>>>> However grounding both ends can cause a ground loop. >>>>>>>> -----Original Message----- From: Matt Hoppes >>>>>>>> Sent: Wednesday, April 24, 2019 9:22 AM >>>>>>>> To: AnimalFarm Microwave Users Group ; dave >>>>>>>> Subject: Re: [AFMUG] Fwd: CAT5. FM. And Rain >>>>>>>> Why do you mean "moved switching closer to the cluster", what is a >>>>>>>> "cluster"? >>>>>>>> Are you saying you floated the copper shields at the base of the tower >>>>>>>> and didn't ground them? >>>>>>>>> On 4/24/19 11:16 AM, dave wrote: >>>>>>>>> Matt, >>>>>>>>> I have that T-shirt For sure.. I was on a FM tower that was only 5kw >>>>>>>>> combined over one 5/8 coax for years. >>>>>>>>> Started with FSK then Cambium gear. >>>>>>>>> The things I noticed worse was the type of cable used. The longest >>>>>>>>> time we had used AL shielded type cable and eventually >>>>>>>>> relocated our switching near the base of the cluster which helped for >>>>>>>>> a while but after some time the AL shielding evaporated and >>>>>>>>> that type of cabling was barely good enough to get 10baseT out of it >>>>>>>>> and still had CRCs >>>>>>>>> We eventually moved to Superior Essex for everything on the tower and >>>>>>>>> used clips,hangers and grommets to get it off the tower leg. >>>>>>>>> Let the copper shields float on the cables and never looked back. >>>>>>>>> We have since moved completely off the tower last year but still >>>>>>>>> didnt have any issues at that time. >>>>>>>>> >>>>>>>>> What I did notice is that when we did move our switching and POE >>>>>>>>> closer to the cluster inside a nema enclosure it cleared a bunch of >>>>>>>>> issues on the cable for a long time. >>>>>>>>> >>>>>>>>> Dave >>>>>>>>> >>>>>>>>> >>>>>>>>>> On 4/20/19 10:06 AM, Matt Hoppes wrote: >>>>>>>>>> What's also interesting is none of the stuff in the shack has >>>>>>>>>> negotiating issues -- so it doesn't seem to be the switch as a whole >>>>>>>>>> getting swamped, but rather the CAT5 getting swamped going up the >>>>>>>>>> tower. >>>>>>>>>> >>>>>>>>>>> On 4/20/19 9:58 AM, Chuck McCown wrote: >>>>>>>>>>> So moisture + rf = Ethernet interference. Just as originally >>>>>>>>>>> stated. No standing waves. >>>>>>>>>>> Is your cat5 in liquidtight? Have you played with grounding & >>>>>>>>>>> ungrounding the shields? How about taking a garden sprayer and >>>>>>>>>>> selectively wetting things? >>>>>>>>>>> >>>>>>>>>>> Sent from my iPhone >>>>>>>>>>> >>>>>>>>>>> Begin forwarded message: >>>>>>>>>>> >>>>>>>>>>>> *From:* Matt Hoppes <[email protected] >>>>>>>>>>>> <mailto:[email protected]>> >>>>>>>>>>>> *Date:* April 20, 2019 at 7:52:12 AM MDT >>>>>>>>>>>> *To:* Chuck McCown <[email protected] <mailto:[email protected]>> >>>>>>>>>>>> *Subject:* *Re: [AFMUG] CAT5. FM. And Rain* >>>>>>>>>>>> >>>>>>>>>>>> Yes. Problem goes away. >>>>>>>>>>>> >>>>>>>>>>>>> On Apr 20, 2019, at 09:51, Chuck McCown <[email protected] >>>>>>>>>>>>> <mailto:[email protected]>> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>> Have you killed the ref when you are having the problem? Might >>>>>>>>>>>>> not be ref related. >>>>>>>>>>>>> >>>>>>>>>>>>> Sent from my iPhone >>>>>>>>>>>>> >>>>>>>>>>>>>> On Apr 19, 2019, at 7:11 PM, Matt Hoppes >>>>>>>>>>>>>> <[email protected] >>>>>>>>>>>>>> <mailto:[email protected]>> wrote: >>>>>>>>>>>>>> >>>>>>>>>>>>>> 19watts >>>>>>>>>>>>>> >>>>>>>>>>>>>>> On 4/19/19 8:58 PM, Chuck McCown wrote: >>>>>>>>>>>>>>> What is the reflected power when you are having problems? >>>>>>>>>>>>>>> Sent from my iPhone >>>>>>>>>>>>>>>> On Apr 19, 2019, at 6:41 PM, Matt Hoppes >>>>>>>>>>>>>>>> <[email protected] >>>>>>>>>>>>>>>> <mailto:[email protected]>> wrote: >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>> My thoughts too. But the reflected power right now is only >>>>>>>>>>>>>>>> 19watts out of 9,000. >>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> On Apr 19, 2019, at 20:14, Chuck McCown <[email protected] >>>>>>>>>>>>>>>>> <mailto:[email protected]>> wrote: >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> My guess is that the FM station has a problem with the >>>>>>>>>>>>>>>>> antenna or transmission line. Moisture throws off impedance >>>>>>>>>>>>>>>>> somewhere and you have a strong standing wave on the >>>>>>>>>>>>>>>>> transmission line. Probably a bad connector. >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>> Sent from my iPhone >>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> On Apr 19, 2019, at 5:52 PM, Matt Hoppes >>>>>>>>>>>>>>>>>> <[email protected] >>>>>>>>>>>>>>>>>> <mailto:[email protected]>> wrote: >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Looking to the wisdom of the AF group on this. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I have some equipment on an FM tower. It’s a 9kw station >>>>>>>>>>>>>>>>>> around 150ft. We are at 250ft with two sectors and a >>>>>>>>>>>>>>>>>> backhaul. Netonix switch in shelter. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Nothing else on the tower. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Normally all is fine. When it rains or is very moist out >>>>>>>>>>>>>>>>>> (heavy heavy fog) we start having major Ethernet negotiation >>>>>>>>>>>>>>>>>> issues. The ports will go from 1Gig to 10F sometimes. >>>>>>>>>>>>>>>>>> Sometimes drop completely. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> I’ve got ferrite beads wrapped about 5 times top and bottom. >>>>>>>>>>>>>>>>>> >>>>>>>>>>>>>>>>>> Any further words of wisdom on what to try? I suspect some >>>>>>>>>>>>>>>>>> odd grounding issue. But not sure how to track it down or >>>>>>>>>>>>>>>>>> isolate it. >>>>>>>>>>>>>>>>>> -- >>>>>>>>>>>>>>>>>> AF mailing list >>>>>>>>>>>>>>>>>> [email protected] <mailto:[email protected]> >>>>>>>>>>>>>>>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>>>>>>>>>>>>>>> -- >>>>>>>>>>>>>>>>> AF mailing list >>>>>>>>>>>>>>>>> [email protected] <mailto:[email protected]> >>>>>>>>>>>>>>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>>>>>>>>>>>>>> -- >>>>>>>>>>>>>>>> AF mailing list >>>>>>>>>>>>>>>> [email protected] <mailto:[email protected]> >>>>>>>>>>>>>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>>>>> -- >>>>>>> AF mailing list >>>>>>> [email protected] >>>>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>>> -- >>>>> AF mailing list >>>>> [email protected] >>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> -- >>> AF mailing list >>> [email protected] >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > -- > AF mailing list > [email protected] > http://af.afmug.com/mailman/listinfo/af_af.afmug.com -- AF mailing list [email protected] http://af.afmug.com/mailman/listinfo/af_af.afmug.com
