If you can read signal strength, that is all you need. Spray it and watch for a change.
Sent from my iPhone > On Jul 22, 2020, at 6:59 PM, Forrest Christian (List Account) > <li...@packetflux.com> wrote: > > > I'll have to do some experiments here to see if I'm comfortable with doing > this. I was hopeful that the vendor would say that the newest modules are > fine being conformally coated, but like I said below, haven't heard back. > > I also have a beta firmware for the rackinjectors in which you're able to > optionally set the pulse mode to the GPS equivalent of "autosync+freerun". > Initial tests show no drops, and reasonable holdover performance. I.E. you > can completely lose signal for several minutes and still be close enough to > sync that you shouldn't have any problems. If you want to give that a > shot, shoot an email into cust...@packetflux.com, and I'll reply with a copy > of the firmware. I guess that goes for anyone else on the list. > > One note about the avantage of this over autosync+freerun is that even if the > GPS at a site drifts in this mode, all of the radios getting sync from that > receivers remain in sync with each other, versus autosync+freerun in the > radios means that each radio in freerun ends up out of sync with the others > in the event of a GPS loss. > >> On Wed, Jul 22, 2020 at 6:53 AM Mark Radabaugh <m...@amplex.net> wrote: >> >> I decided to try a conformal coating on the Syncbox to see if it would cause >> any problems with the GPS and avoid the corrosion issues we have seen. We >> tested before and after the conformal coating with no detectable impairment >> to the GPS SNR and signal level. >> >> Only about 16 hours so far but throwing a pitcher of water on it and leaving >> the cover off all night in a rainstorm hasn’t seemed to bother it. The >> picture didn’t catch the sync light but it’s happily blinking away. There >> is a lot of silicon grease on/around the RJ45 which looks a bit funny but I >> can’t conformal coat the jack itself for obvious reasons and I was intending >> to douse this one with water. I’m sure SNR is bad right now with a blob of >> water on top of the antenna but it’s picking up enough to stay in lock. >> >> Going to leave it like this and give it a couple weeks to see how it holds >> up, but so far so good. >> >> Regarding loss of sync on 450 equipment - on further examination of the logs >> we are seeing issues with 450 equipment randomly losing sync or switching to >> free-run and back to sync-over-power across a number of injectors - CMM5, >> CTM-2, and Rackinjectors. These issues started about the time we started >> deploying SyncInjectors but it’s really looking like that is coincidental. >> Data is pointing toward something that changed with the firmware rather than >> the injector. I have not had time yet to see if it included the older 450 >> versus 450i yet. >> >> Mark >> >> <IMG_3364.jpeg> >> >>> On Jul 13, 2020, at 10:28 PM, Forrest Christian (List Account) >>> <li...@packetflux.com> wrote: >>> >>> You bring up a few fair, and known, points. I'll respond to at least a few >>> of them: >>> >>> In relation to the water ingress, we've seen enough of these to know it's >>> at least an occasional issue. Especially in hotter climates, one thing >>> we've seen is the gasket cracking in the enclosure. I'm also not >>> completely convinced this isn't a water condensation/surface moisture issue >>> in damper climates. Our enclosure manufacture just switched the gasketing >>> material, perhaps as a result of our whining, to something different. >>> I've also looked at various alternatives for enclosures but haven't found >>> the right one yet. I thought I had one which would have been perfect, >>> until I got the $50 per unit quote in quantity. Some days I miss the >>> pipes, but it was time for them to go from a mostly marketing perspective. >>> >>> I've also looked at the conformal coating in the past, and the challenge >>> has been that the GPS module manufacture has told us this is a no-no since >>> it apparently changes the tuning of the GPS patch antenna. I probably >>> need to re-evaluate this now that there's a different patch antenna on the >>> new modules - but I expect a similar answer. >>> >>> For the past couple of years, I've been trying to move to a module flat on >>> the board and then either using a PCB antenna like is used in devices like >>> cell phones, where the antenna's pattern is such that mounting it flat on >>> vertically oriented PCB results in a vertical pattern like the patch has. >>> This should solve the water getting on the antenna issue, as there won't be >>> anything directly below the seam to leak on. The holdup has been me >>> trying to possibly move to a module with a different GPS chipset at the >>> same time, hoping that this would be better than our existing module. >>> With all the warts (some of which will be described below), I'm finding >>> that the modules/chipset that we're using is actually not that bad in >>> comparison to some others. I even have had an eval of a 'timing grade' >>> gps receiver here, which had more failures than the non-timing-grade ones >>> we're using. I have a few more to qualify, but look for this change in >>> coming months assuming I can find a suitable module and antenna which works. >>> >>> In relation to the random timing loss of lock, I am not going to disagree >>> with you at all. I suspect some of this might be leftovers from the >>> GPS+GLONASS issue from the end of the year which seems to have resolved >>> itself for the most part, but I know enough about that bug that it wouldn't >>> shock me to find that there are still lingering issues. The problem here >>> is that although it 'feels' like there might be more issues, I don't have >>> quantifiable numbers. With all of that in mind, I'm currently working on >>> in-field upgrade procedures for upgrading the firmware for these modules to >>> get them the GLONASS fix. This seems to be a more troublesome problem than >>> it should be, since it's just an issue of getting the right firmware - the >>> problem being that the company who built the firmware for these got gobbled >>> and the successor company tends to be more difficult to work with. I have >>> firmware which does work on the modules, it just isn't an official build by >>> the manufacturer. >>> >>> Around the end of the year, we did switch our basics to a newer module, >>> based on the same chipset. The Basics shipped since then default to >>> GPS+GALILEO. Recently we've been using this module in Aux Port and >>> Deluxes, but with GPS+GLONASS+Fixed-Glonass firmware since the Cambium >>> firmware doesn't understand (yet) the Galileo sentences. So anything you >>> get from us today has this latest chipset in it, and has the GLONASS fix >>> even if it isn't enabled. I will say that testing and in-field reports >>> indicates this is even more stable, not sure how much of it is because of >>> the increased antenna gain, and how much of it is due to the updated >>> firmware, or how much is just a side effect of having a lot more of the >>> older units in the field having customers report problems on. I know at >>> least some of it is measurable on the bench here, so it isn't all based on >>> field reports. The only downside so far is that we do see an uptick in >>> DoA's (but still well under 1%). Frustratingly, the DoA's we've gotten >>> back have somehow resurrected themselves between the field and here, but >>> thankfully there doesn't seem to be any increased in-field failures that we >>> can see other than the DoA's. >>> >>> To Eric's point about the holdover timer.. I understand the CTM2's had >>> this functionality built in. Nothing else I'm aware of has had that except >>> for some our early GPS modules which just produced a pulse no matter what, >>> and when it could align it it would. This was good in the early days, not >>> so much nowadays. >>> >>> I'm looking at a couple options to implement a holdover. First of all, >>> assuming the docs are correct, I can tell the GPS modules to produce sync >>> all the time, or only when they have a 2D lock, or when they have a 3d >>> lock. Sync all the time can be bad. Especially if you're not monitoring >>> lock status, since it means that a GPS can be out of lock but producing >>> sync pulses which are wildly wrong, causing all sorts of issues. 2d lock >>> can be bad too since it shares similar issues. As a result, the modules >>> default to '3d lock'. I've been toying with doing something dynamic in >>> the rackinjector where it is able to dynamically changes the mode, so it >>> waits until you get 3d lock, and then since it should have a good position, >>> switches to '2d lock' mode, or maybe even freerun. At the bare minimum, I >>> probably will allow customers to change the setting statically if they're >>> willing to deal with the ramifications. >>> >>> I have some other ideas I'm cooking up as well, just don't want to say too >>> much until I'm actually a bit farther down the path. >>> >>> >>>> On Mon, Jul 13, 2020 at 5:57 AM Mark Radabaugh <m...@amplex.net> wrote: >>>> Forrest, >>>> >>>> As usual there are probably multiple issues going on. We have seen an >>>> increase in the number of DFS hits recently, and we also have a lot of >>>> Packetflux timing equipment on the network. I have noticed that DFS hits >>>> tend to be worse in ‘unusual’ hot weather conditions. And we have >>>> certainly seen a pretty unusual heat wave over the last few weeks. I’m >>>> not sure if this is just heat changing sensitivity of the DFS detections >>>> (temperature is involved in the RF calibration), if there is more >>>> reflection off the ionosphere in these weather conditions, or if the >>>> weather radar systems are just really jacking up power looking for storms. >>>> >>>> >>>> As far as timing - I do think there is some timing instability going on >>>> but I can’t pin it down to anything specific. We continue to struggle >>>> with RackInjectors losing the GPS timing signal from the Syncbox Basic >>>> during or after storm events. Typical symptom in the RackInjector fails >>>> to see sync from the syncbox and the AP’s go into freerun. Sat’s in view, >>>> etc. all look normal, just no pulses. Sometimes a power cycle from the >>>> RackInjector will fix it, sometimes physically unplugging it will fix it, >>>> and sometimes you just have to wait. I have instructed the field crews >>>> multiple times to make absolutely sure they screw in every screw tight on >>>> the syncbox but I’m not 100% sure they are doing that. I have seen at >>>> least one come back to the shop with evidence of water damage to the GPS >>>> board at the top. I would really like to see the extra step of conformal >>>> coating on the boards if there isn’t a reliable way of keeping water off >>>> of them. >>>> >>>> We have also been seeing an unusual number of LBT issues with the 3.65 >>>> gear which I believe are related to other AP’s drifting or briefly going >>>> off timing. >>>> >>>> Due to the number of times we were seeing loss of sync we had to enable >>>> sync + freerun in order to avoid session resets. I’m not convinced that >>>> we are not still seeing timing jumps due to the sequence of loss of sync, >>>> into freerun, then an abrupt change in framing when sync comes back. Any >>>> time something like that happens it tends to cause a wave of DFS and LBT >>>> events across the network. I can’t necessarily show anything specific at >>>> this point though. We do get a lot of archived and searchable logging >>>> from our Sumologic syslog server. I’m going to ask the NOC to put >>>> together a report of AP’s reporting timing recovery and any correlation >>>> with DFS or LBT events within a 60 second window and see what we get. >>>> >>>> Mark >>>> >>>>> On Jul 13, 2020, at 3:19 AM, Forrest Christian (List Account) >>>>> <li...@packetflux.com> wrote: >>>>> >>>>> I need to be a bit clearer in that I'm not really sure what version this >>>>> customer is running. The question about 15.x /16.x came from a couple >>>>> of oldish threads which indicated that something broke early in 15, and >>>>> that it still wasn't fixed in 16. But I found that unlikely to still be >>>>> the case another year or two on. In these year-and-a-bit old threads, >>>>> the report was that one had to go back to very early in 15.x to "fix" >>>>> this issue. But like I've said before in this paragraph - I find this >>>>> unlikely to still be the case - I just was hoping to verify that this >>>>> wasn't a common knowledge issue that DFS was broken on 16.x. >>>>> >>>>> I know this customer has been in contact with Cambium. Based on our >>>>> conversations with the customer so far, I get the impression that for >>>>> some reason they've decided this is a sync issue. I don't know if this >>>>> is a customer determination or if Cambium has told them this. I like >>>>> your word dubious as I'm skeptical as well, but I'm also not one to >>>>> dismiss a possible cause until I fully rule it out, as they could be 100% >>>>> correct. >>>>> >>>>> I could see where if you have an AP with sync broken intermittently >>>>> (especially if you have freerun on), you might end up with a DFS event as >>>>> a result of things just not being in sync. But I have reason to believe >>>>> this isn't the case with any of their AP's - at least not the ones I have >>>>> seen the GPS status screen on the RackInjector for. >>>>> >>>>> I could also see where a stray pulse or two may be misinterpreted by the >>>>> AP to be the correct alignment and have the same effect with causing AP >>>>> to transmit out of sync as well. But generally, the radios should ignore >>>>> these as they're very rare (and exist in both the PacketFlux and official >>>>> Cambium gear, so if it's a problem with mine, it should be a problem with >>>>> the official gear as well). >>>>> >>>>> And I agree with you 100% about a dislike for DFS. I have a feeling that >>>>> this customer isn't going to help me change my opinion. >>>>> >>>>> >>>>>> On Sun, Jul 12, 2020 at 8:23 PM Ken Hohhof <af...@kwisp.com> wrote: >>>>>> I am unaware of any correlation between DFS events and either Packetflux >>>>>> or 15.x FW. >>>>>> >>>>>> >>>>>> >>>>>> I don’t use a lot of DFS because honestly it seems fussy no matter what. >>>>>> But I have a tower with 10 sectors in 5 GHz (8 x 450i and 2 x 450m). >>>>>> They are all synced from a Packetflux Rackinjector using Cambium Sync. >>>>>> 4 of the 450i sectors are in 5.4 DFS, and I’m embarrassed to find they >>>>>> are still on 15.2 FW. Uptime of about 6 months and no DFS events. So >>>>>> I’m dubious about all of this. >>>>>> >>>>>> >>>>>> >>>>>> The latest production FW is 16.2.1 and it also has a lot of fixes so I’m >>>>>> not sure why you would be running something so far behind. As I said, >>>>>> I’m embarrassed to find I still have radios on 15.2. >>>>>> >>>>>> >>>>>> >>>>>> Has he opened a case with Cambium support? There are some best >>>>>> practices with DFS. For sure you don’t want to configure the AP to >>>>>> think the antenna gain is lower than it is (not possible with 450m or >>>>>> integrated 450i). You don’t want to set the SM Receive Target Level >>>>>> higher than necessary on other sectors. Then there’s choosing the >>>>>> alternate frequencies. And I suppose a poor sync configuration could >>>>>> cause false DFS detections, where an AP sees the signal from an adjacent >>>>>> AP. >>>>>> >>>>>> >>>>>> >>>>>> But who knows what causes these events? Somebody’s Linksys reflected >>>>>> off a bird? A competitor aiming a new radio? I used to have a 5.4 GHz >>>>>> PTP500 backhaul and the end pointed in the general direction of Chicago >>>>>> would have DFS events when there were storms. I thought ducting was >>>>>> causing it to see distant signals, but it could also have been tripped >>>>>> by lightning. DFS is fussy. I don’t like it. If I could swap out all >>>>>> the SMs on those DFS sectors for 450b, I would probably move them to >>>>>> U-NII-1. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> From: AF <af-boun...@af.afmug.com> On Behalf Of Forrest Christian (List >>>>>> Account) >>>>>> Sent: Sunday, July 12, 2020 7:56 PM >>>>>> To: AnimalFarm Microwave Users Group <af@af.afmug.com> >>>>>> Subject: Re: [AFMUG] 450i/450m DFS false detect problem solved in later >>>>>> firmware? >>>>>> >>>>>> >>>>>> >>>>>> I read the 16.0.1 release notes, nothing really specific about DFS other >>>>>> than it being on when it shouldn't be. However, I agree there is lots >>>>>> of stuff fixed in there, some of which could have repercussions for DFS. >>>>>> >>>>>> >>>>>> >>>>>> Are you saying that mid to late 15.x was generally broken for DFS and >>>>>> this is largely fixed in 16.x? I guess my real question should have >>>>>> been 'What is the state of DFS in the 450 platform and how fussy is it'? >>>>>> >>>>>> >>>>>> >>>>>> I'm still gathering information from this customer but it sounds like >>>>>> they're still trying to track down the root cause. Sometime in the past >>>>>> week or so they figured out that there was some correlation between the >>>>>> DFS events adding a fair bit of PacketFlux gear, so this correlation is >>>>>> now the leading root cause in their minds. So now I get to try to >>>>>> resolve their problem for them. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Sun, Jul 12, 2020 at 3:00 PM Dave <dmilho...@wletc.com> wrote: >>>>>> >>>>>> If they are not running 16.0.1 nuthing can help them from some weird >>>>>> issues with the DFS bands. >>>>>> >>>>>> Lots of things corrected in 15.2 and later for EIRP and SNR related >>>>>> calculations the help with H/V misreads and A/B channel alignments. >>>>>> >>>>>> Read the release notes in 16.0.1 for further info. >>>>>> >>>>>> >>>>>> >>>>>> On 7/11/2020 3:12 AM, Forrest Christian (List Account) wrote: >>>>>> >>>>>> I'm working with a customer that is having problems with DFS false hits >>>>>> who is convinced this is a PacketFlux sync issue. I'm never one to say >>>>>> it definitively isn't my problem, but I'm skeptical in this case. >>>>>> >>>>>> >>>>>> >>>>>> I know that at some point in the past that anything beyond 15.0.2 was >>>>>> known to have fairly common DFS issues by some customers. I thought >>>>>> this was resolved in later releases, but I also don't see any mention of >>>>>> said issue being resolved in any release notes post 15.0.02. >>>>>> >>>>>> >>>>>> >>>>>> I was wondering if anyone knew the current status? I.E. if they had >>>>>> been seeing the problem previously, and then discovered it was fixed. >>>>>> Or have tried recent releases and discovered the problem still exists, >>>>>> etc... >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> >>>>>> - Forrest >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> AF mailing list >>>>>> AF@af.afmug.com >>>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> >>>>>> - Forrest >>>>>> >>>>>> -- >>>>>> AF mailing list >>>>>> AF@af.afmug.com >>>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>>> >>>>> >>>>> -- >>>>> - Forrest >>>>> -- >>>>> AF mailing list >>>>> AF@af.afmug.com >>>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>>> >>>> -- >>>> AF mailing list >>>> AF@af.afmug.com >>>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >>> >>> >>> -- >>> - Forrest >>> -- >>> AF mailing list >>> AF@af.afmug.com >>> http://af.afmug.com/mailman/listinfo/af_af.afmug.com >> >> -- >> AF mailing list >> AF@af.afmug.com >> http://af.afmug.com/mailman/listinfo/af_af.afmug.com > > > -- > - Forrest > -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com
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