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
