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
