Ok, I popped the lid here... after realizing it's able to be opened withoud desoldering. I take it back... There are several 33.2 Ohm resistors which are wired suspiciously like heaters.... This now is starting to make some sense.
On Thu, Jan 21, 2016 at 9:19 AM, Forrest Christian (List Account) < li...@packetflux.com> wrote: > Darn FCC site... expires links way too quickly. > > The SM pictures look like they MIGHT have one. > > On Thu, Jan 21, 2016 at 9:15 AM, Forrest Christian (List Account) < > li...@packetflux.com> wrote: > >> I remember hearing the same thing, which is why I went looking at the >> photos. See >> https://apps.fcc.gov/eas/GetApplicationAttachment.html?id=2053606 >> >> There aren't any that I can see, even under the cans. I thought that >> perhaps looking at the actual board would reveal some, but I sure don't see >> any. On the SM perhaps? >> >> On Thu, Jan 21, 2016 at 9:08 AM, Adam Moffett <dmmoff...@gmail.com> >> wrote: >> >>> They have said there's a resistive heater. I heard it in ePMP training >>> in Albany and I've seen it stated on this list. >>> >>> If I remember correctly (I might not), they wanted the CPU to hit a >>> certain temp before starting up. If it was too cold you'd see a delay in >>> startup of up to 2 minutes while waiting for this heater to bring the CPU >>> up to temp. I've never actually observed the delay, so I guess they're >>> talking about Alaska cold, not NY cold. >>> >>> >>> On 1/21/2016 10:47 AM, Forrest Christian (List Account) wrote: >>> >>> I looked at the high resolution photos on the FCC site and didn't see >>> anything obvious. Now I've got the one I have on the bench out of the >>> case, I still don't see anything obvious heater-wise, but again I'm not >>> going to pop the shields off the board (requiring desoldering), to be 100% >>> sure... >>> >>> On Thu, Jan 21, 2016 at 8:30 AM, Steve D <bigd...@gmail.com> wrote: >>> >>>> Just throwing this out there, but don't the epmp's have a small heater >>>> in them that could be turning on when it's cold, drawing additional power? >>>> I recall it was supposed to pre-heat components to avoid freezeup on first >>>> boot but I can't recall if that's the only time they run or not. >>>> >>>> -Steve D >>>> >>>> On Thu, Jan 21, 2016 at 1:44 AM, Forrest Christian (List Account) < >>>> li...@packetflux.com> wrote: >>>> >>>>> I do want to clarify one item: >>>>> >>>>> This is not necessarily related to the cambium DRAM issue. I don't >>>>> want to claim that problem, since this isn't the same thing. This is >>>>> more >>>>> of an issue where you have ePMP's which seem to start having power-related >>>>> issues. If moving to a 30V brick makes your problem go away, then the >>>>> issue I describe below probably is your issue. If moving to a higher >>>>> voltage doesn't fix the issue then this probably doesn't relate to your >>>>> issue. Regardless, it is my intent to recommend that my customers move to >>>>> 48V as soon as I confirm that this seems to fix at least a decent number >>>>> of >>>>> the problems without causing others. >>>>> >>>>> Unfortunately this might be a case of the cold weather aggravating two >>>>> separate issues (or for that matter, the cold weather causing increased >>>>> current consumption in the ePMP, which then requires a higher voltage to >>>>> operate correctly). >>>>> >>>>> -forrest >>>>> >>>>> On Thu, Jan 21, 2016 at 12:43 AM, Forrest Christian (List Account) < >>>>> <li...@packetflux.com>li...@packetflux.com> wrote: >>>>> >>>>>> A bit of an update from the PacketFlux side. >>>>>> >>>>>> Late this afternoon I received a ticket from Tyson in relation to >>>>>> these issues. In particular, sync from a PacketFlux SyncInjector >>>>>> dropping >>>>>> off on an ePMP when it's cold. I have spent a bit of time this evening >>>>>> investigating this issue. The following is a summary of what I found. >>>>>> It's a bit long-winded so that those experiencing the problems can >>>>>> understand my current working theory and help me figure out if this is >>>>>> the >>>>>> case. >>>>>> >>>>>> WARNING: The following is based on a limited amount of testing with >>>>>> a single ePMP with no traffic and no clients and on a bench. This is >>>>>> likely the best case scenario. The field is only going to be worse. >>>>>> >>>>>> The setup is as follows: >>>>>> >>>>>> ePMP 1000 GPS AP, with no GPS hockey puck attached, connected to a >>>>>> Gigabit Syncinjector (Rev H and Rev I - I have a special one with a port >>>>>> of >>>>>> each 'type' ;-) ). I am powering the injector with a variable power >>>>>> supply so I can vary the voltages in. The AP is connected to the >>>>>> Injector >>>>>> with ~100m of CAT5 cable. The Antenna connectors have terminators on >>>>>> them, the AP is in transmit mode, but isn't passing any traffic since >>>>>> there >>>>>> are no clients. >>>>>> >>>>>> When feeding the injector with 24V, I get about 23V at the AP. This >>>>>> is pretty consistent with what I would expect in this situation. The AP >>>>>> seems to work fine, at least on the bench and without doing any real >>>>>> work. However, as the voltage drops, things start to get weird: >>>>>> >>>>>> At around 22V in, (21V at the AP), Sync becomes flaky. This is >>>>>> consistent on both H and I version ports on the injector. Sometimes it >>>>>> works, sometimes it doesn't. Note that 22V is the bottom of the rated >>>>>> voltage inputs for the ePMP. >>>>>> >>>>>> At around 20.5V in (19.5V at the AP), the radio just turns off. It >>>>>> won't turn back on until around 22V. >>>>>> >>>>>> Now here's where some total speculation comes to play. On the >>>>>> bench, this unit is drawing around 3W. Let's assume that under load, and >>>>>> when temperatures are cold, this unit draws closer to 6W. This would >>>>>> double the current, and quadruple the voltage drop. Now, assume 24V in, >>>>>> this puts you at around 20V in at the AP, which is about the turnoff >>>>>> point. Remember this is on 100m of wire, and a total speculation about >>>>>> a >>>>>> the power draw of a cold, under load AP. But the point is valid, >>>>>> regardless of the cause - if the circuit resistance when combined with >>>>>> the >>>>>> power load causes a low enough voltage at the AP, weird things will >>>>>> happen. And since weird things seem to start to happen around 22V, there >>>>>> just isn't much headroom at 24V. >>>>>> >>>>>> This explains why things work well at 30V. >>>>>> >>>>>> For those who are having this problem I'd recommend trying increasing >>>>>> the voltage into the SyncInjector. The Revision H injectors can safely >>>>>> handle up to around 56V or so. Assuming all of the radios on an >>>>>> injector >>>>>> are either ePMP or the newer 450i's, using 56V into a SyncInjector is >>>>>> perfectly acceptable and the ePMP's are rated up to 56V as well. >>>>>> >>>>>> So the summary: Try a 48VDC voltage source instead of 24V and see >>>>>> what happens. >>>>>> >>>>>> -forrest >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Wed, Jan 20, 2016 at 11:00 AM, Tyson Burris @ Internet >>>>>> Communications Inc < <t...@franklinisp.net>t...@franklinisp.net> wrote: >>>>>> >>>>>>> Hello Cambium, >>>>>>> >>>>>>> >>>>>>> >>>>>>> At the MidWest-IX launch party last night, several of us Indiana >>>>>>> WISPs compared notes on the ‘cold weather’ problems we are seeing with >>>>>>> ePMPs. It was very interesting to learn we are experience identical >>>>>>> problems across the spectrum. >>>>>>> >>>>>>> We all understand this is a DRAM issue with certain units you have >>>>>>> identified. We also understand the firmware RC that has been made >>>>>>> available to fix this short term. >>>>>>> >>>>>>> The bottom line is we are very frustrated and grow tired of dealing >>>>>>> with it. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Our concern is simple. If your software fix ‘degrades’ the >>>>>>> performance of the product or triggers other issues, as it has been >>>>>>> suggested, we would prefer a full recall and replacement program >>>>>>> immediately. >>>>>>> >>>>>>> >>>>>>> >>>>>>> If the suggestion that the fix will degrade the product performance >>>>>>> is inaccurate and not cause other issues, I would like for this to be >>>>>>> made >>>>>>> public. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Thank you, >>>>>>> >>>>>>> >>>>>>> >>>>>>> *Tyson Burris, President* >>>>>>> *Internet Communications Inc.* >>>>>>> *739 Commerce Dr.* >>>>>>> *Franklin, IN 46131* >>>>>>> >>>>>>> *317-738-0320 <317-738-0320> Daytime #* >>>>>>> *317-412-1540 <317-412-1540> Cell/Direct #* >>>>>>> *Online: * <http://www.surfici.net>*www.surfici.net >>>>>>> <http://www.surfici.net>* >>>>>>> >>>>>>> >>>>>>> >>>>>>> [image: ICI] >>>>>>> >>>>>>> *What can ICI do for you?* >>>>>>> >>>>>>> >>>>>>> *Broadband Wireless - PtP/PtMP Solutions - WiMax - Mesh >>>>>>> Wifi/Hotzones - IP Security - Fiber - Tower - Infrastructure.* >>>>>>> >>>>>>> *CONFIDENTIALITY NOTICE: This e-mail is intended for the* >>>>>>> *addressee shown. It contains information that is* >>>>>>> *confidential and protected from disclosure. Any review,* >>>>>>> *dissemination or use of this transmission or its contents by* >>>>>>> *unauthorized organizations or individuals is strictly* >>>>>>> *prohibited.* >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>>>>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>>>>> <forre...@imach.com>forre...@imach.com | http://www.packetflux.com >>>>>> <http://www.linkedin.com/in/fwchristian> >>>>>> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>>>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>>>> <forre...@imach.com>forre...@imach.com | http://www.packetflux.com >>>>> <http://www.linkedin.com/in/fwchristian> >>>>> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >>>>> >>>>> >>>> >>> >>> >>> -- >>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>> <forre...@imach.com>forre...@imach.com | <http://www.packetflux.com/> >>> http://www.packetflux.com >>> <http://www.linkedin.com/in/fwchristian> >>> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >>> >>> >>> >> >> >> -- >> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >> forre...@imach.com | http://www.packetflux.com >> <http://www.linkedin.com/in/fwchristian> >> <http://facebook.com/packetflux> <http://twitter.com/@packetflux> >> >> > > > -- > *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* > Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 > forre...@imach.com | http://www.packetflux.com > <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> > <http://twitter.com/@packetflux> > > -- *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 forre...@imach.com | http://www.packetflux.com <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> <http://twitter.com/@packetflux>
