One other option is to put 48VDC in at the bottom of the coax, and then use a DC-DC converter at the top. I'm particularly fond of the meanwell rsd series, specifically the meanwell RSD-150C-24 should do just fine. Assuming you don't have more than 150W of radios up top. If you need less/more there are smaller/larger options available.
On Tue, May 15, 2018 at 9:35 AM, Forrest Christian (List Account) < [email protected]> wrote: > You don't lose any voltage until the radios start drawing power, so it > generally isn't 100% safe to boost it beyond what the radios are rated > for. I'd set the voltage at the bottom to the absolute maximum you know > the radios are fine with. Then it can only go down from there. > > > > On Tue, May 15, 2018 at 9:20 AM, Josh Luthman <[email protected] > > wrote: > >> Reason I ask is if at the bottom I believe it's 24v and the top it's >> 24v. I'm using that heavy duty coax (inch and a half?) up the tower for my >> DC. I think the center conductor was 8mm. >> >> If you're doing say 27.4v at the bottom and 100' of two pair 24 gauge, >> it's more like 26.83v at the top. I'm not losing that ~0.6v. >> >> I really don't want to fry anything and start replacing radios :( >> >> >> Josh Luthman >> Office: 937-552-2340 >> Direct: 937-552-2343 >> 1100 Wayne St >> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >> Suite 1337 >> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >> Troy, OH 45373 >> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >> >> On Tue, May 15, 2018 at 11:15 AM, Forrest Christian (List Account) < >> [email protected]> wrote: >> >>> The UBNT stuff used to be a lot more sensitive than it is. Anything >>> modern should be fine up to 28V on the 24V radios. >>> >>> On Tue, May 15, 2018 at 7:34 AM, Josh Luthman < >>> [email protected]> wrote: >>> >>>> Sweet! I'll crank up the power supply another volt. IIRC Ubnt stuff >>>> dies at 26 or 27 volts, so you can see why I aimed for right at 24v. >>>> >>>> >>>> Josh Luthman >>>> Office: 937-552-2340 >>>> Direct: 937-552-2343 >>>> 1100 Wayne St >>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >>>> Suite 1337 >>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >>>> Troy, OH 45373 >>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >>>> >>>> On Sun, May 13, 2018 at 9:21 AM, Josh Baird <[email protected]> >>>> wrote: >>>> >>>>> Agreed. I expect your issues will go away if you increase voltage. >>>>> We run all ePMP @ 48VDC. It fixed these random rebooting issues for us. >>>>> >>>>> On Sun, May 13, 2018 at 6:37 AM, Forrest Christian (List Account) < >>>>> [email protected]> wrote: >>>>> >>>>>> 22.93 is too low. Cambium says 23V is the minimum into the radio. >>>>>> See http://community.cambiumnetworks.com/t5/ePMP-Installatio >>>>>> n/ePMP-PoE-Powering-Primer/td-p/49944 >>>>>> >>>>>> You need to subtract a bit of loss inside the injector, and then a >>>>>> bit more for cabling. Plus a bit more for everything else. >>>>>> >>>>>> For verification, I took my bench ePMP and hooked it up to my power >>>>>> supply - it doesn't even turn on until 22.5V at the radio. I'm sure >>>>>> other >>>>>> copies are probably higher or lower. And I'm sure it changes with >>>>>> internal temperature of the radio. >>>>>> >>>>>> One big difference between the PoE Injector and the SyncInjector is >>>>>> that the syncinjector uses semiconductor switches which generally have a >>>>>> bit more voltage drop than a relay. The tradeoff is that the >>>>>> semiconductor >>>>>> switches can switch far more power than the relays can and can switch >>>>>> quickly enough to do sync over power. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Sat, May 12, 2018 at 10:26 PM, Josh Luthman < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> So we replaced all 8 surge cards. It's getting 22.95 and 22.93 for >>>>>>> the two boxes (to the green terminal). Devices are still rebooting... >>>>>>> >>>>>>> Epmp never has problems with the same DC supply through the green >>>>>>> POE injector, forgot to mention that. >>>>>>> >>>>>>> >>>>>>> Josh Luthman >>>>>>> Office: 937-552-2340 >>>>>>> Direct: 937-552-2343 >>>>>>> 1100 Wayne St >>>>>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >>>>>>> Suite 1337 >>>>>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >>>>>>> Troy, OH 45373 >>>>>>> <https://maps.google.com/?q=1100+Wayne+St+Suite+1337+Troy,+OH+45373&entry=gmail&source=g> >>>>>>> >>>>>>> On Sun, May 6, 2018 at 8:14 PM, George Skorup < >>>>>>> [email protected]> wrote: >>>>>>> >>>>>>>> Funny story if you were using ePMP near the beginning. Some of the >>>>>>>> first original 5GHz integrated radios had labels marked 56VDC. They >>>>>>>> were >>>>>>>> definitely NOT capable of being powered from 48/56V. Somebody screwed >>>>>>>> up. >>>>>>>> >>>>>>>> Yeah. We've run Force180/200 survey setups on a small 12V SLA too. >>>>>>>> It works, but they're rated at 14 volts. Same with the 100 and 450 SMs. >>>>>>>> Still works. However, I recall the regulator is very inefficient down >>>>>>>> that >>>>>>>> low. Like the old 320 and 430 APs could be run on 24VDC, but you really >>>>>>>> didn't want to do that, and Motorola/Cambium said it was completely >>>>>>>> unsupported. >>>>>>>> >>>>>>>> >>>>>>>> On 5/6/2018 5:13 PM, Bill Prince wrote: >>>>>>>> >>>>>>>>> I had a portable 12V battery that I would use for site surveys >>>>>>>>> with the old PMP100. I'm pretty sure they would function in the 8-10V >>>>>>>>> region. >>>>>>>>> >>>>>>>>> I know nothing about the ePMP radios. Trust George. >>>>>>>>> >>>>>>>>> >>>>>>>>> bp >>>>>>>>> <part15sbs{at}gmail{dot}com> >>>>>>>>> >>>>>>>>> On 5/6/2018 2:33 PM, George Skorup wrote: >>>>>>>>> >>>>>>>>>> Original 5GHz integrated and connectorized are 14-30VDC, -4/5 >>>>>>>>>> +7/8 only. >>>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> *Forrest Christian* *CEO**, PacketFlux Technologies, Inc.* >>>>>> Tel: 406-449-3345 | Address: 3577 Countryside Road, Helena, MT 59602 >>>>>> <https://maps.google.com/?q=3577+Countryside+Road,+Helena,+MT+59602&entry=gmail&source=g> >>>>>> [email protected] | 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 >>> <https://maps.google.com/?q=3577+Countryside+Road,+Helena,+MT+59602&entry=gmail&source=g> >>> [email protected] | 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 > <https://maps.google.com/?q=3577+Countryside+Road,+Helena,+MT+59602&entry=gmail&source=g> > [email protected] | 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 [email protected] | http://www.packetflux.com <http://www.linkedin.com/in/fwchristian> <http://facebook.com/packetflux> <http://twitter.com/@packetflux>
