I should have said -- at least the WTM4200 and WTM4800, both of which I have used.
On Mon, Sep 21, 2020 at 10:59 AM Josh Baird <joshba...@gmail.com> wrote: > Aviat radios don't bond + or - to the chassis. You can run them at -48VDC > or +48VDC. > > On Mon, Sep 21, 2020 at 10:45 AM Steve Jones <thatoneguyst...@gmail.com> > wrote: > >> So, like on these aviats, my contractor says they're -48v, but the >> connector in the radio bonds to ground. Does that mean my whole site has to >> have -48v or just radios powered by that particular psu? >> >> On Mon, Sep 21, 2020, 8:59 AM Ken Hohhof <af...@kwisp.com> wrote: >> >>> Now if we could get the manufacturers to be less secretive about their >>> POE schemes. They mostly want you to use their POE device and don’t want >>> to document the pinouts or explain if it matters which side is referenced >>> to ground. >>> >>> >>> >>> Mostly I find that using a Cat6-POE-APC with the jumpers as set at the >>> factory and + and – hooked up per the markings works. Which is basically >>> 802.3at. It works with the – side grounded, I suspect it would also work >>> with the + side grounded, or neither. I was hesitant to use this on a >>> PTP820 but it works fine. I don’t know why they make their POE scheme >>> sound so mysterious. >>> >>> >>> >>> >>> >>> *From:* AF <af-boun...@af.afmug.com> *On Behalf Of *Josh Baird >>> *Sent:* Monday, September 21, 2020 8:44 AM >>> *To:* AnimalFarm Microwave Users Group <af@af.afmug.com> >>> *Subject:* Re: [AFMUG] -48 noob questions (mikrotik) >>> >>> >>> >>> Yep - great explanation! >>> >>> >>> >>> On Sun, Sep 20, 2020 at 4:55 PM Chuck McCown <ch...@wbmfg.com> wrote: >>> >>> You have a power supply, say a 6 volt car battery. You connect a pair >>> of headlights to it with two wires. All is well. >>> >>> >>> >>> Now you start building cars. And you are going to wire up the >>> headlights. Someone points out that you can save some money on wiring by >>> using the car chassis instead if one of the wires. >>> >>> >>> >>> You decide to run the positive connection from the battery to the >>> headlights with wire and return the current via the car’s chassis. >>> >>> >>> >>> Now you have turned a 6 volt electrical system into a +6 volt system. >>> If you reverse the battery and connect the + side to the chassis and run >>> the wire from the negative post to the headlights , it will still work >>> fine. The headlights don’t care. Now you have a -6 volt electrical >>> system. >>> >>> >>> >>> The headlights don’t care but the radio does. Most radios expect the >>> chassis to be negative and their power wire to be positive. You can >>> “float” the radio by mounting it on an insulator and connecting its power >>> wire to the car’s chases and the chassis of the radio to the negative wire >>> going to the battery. A bit dangerous but I have had to do this at times. >>> >>> >>> >>> Oh, and the car is an early VW. >>> >>> Sent from my iPhone >>> >>> >>> >>> On Sep 20, 2020, at 2:19 PM, Steve Jones <thatoneguyst...@gmail.com> >>> wrote: >>> >>> >>> >>> I still cant comprehend any of this. I'm just dumb when it comes to it >>> >>> >>> >>> On Sat, Sep 19, 2020, 2:51 PM <ch...@wbmfg.com> wrote: >>> >>> Yes. >>> >>> >>> >>> *From:* TJ Trout >>> >>> *Sent:* Saturday, September 19, 2020 1:48 PM >>> >>> *To:* AnimalFarm Microwave Users Group >>> >>> *Subject:* Re: [AFMUG] -48 noob questions (mikrotik) >>> >>> >>> >>> It's just a simple 48 to 12v converter to feed the mikrotik. I tested >>> with a ict +48 supply and the 12v comes out fine, I'm 99% sure it will work >>> on the wood bench, and about 90% sure it will work in a rack. >>> >>> >>> >>> If it was true -48 I would assume the + terminal would be bonded with >>> chassis ground? >>> >>> >>> >>> On Sat, Sep 19, 2020, 12:45 PM TJ Trout <t...@voltbb.com> wrote: >>> >>> I think some of my devices have the chassis ground bonded with the >>> negative input terminals, I discovered this >>> because I am running a telecom rectifier shelf designed for -48 on a +48 >>> system because it's floating, but this >>> causes the + output to not be fused, so I practiced arc welding once. >>> >>> Strange, didn't know the 1100 had dc input, but it looks floating though >>> (per specs -48, 12-57 V) >>> >>> >>> >>> >>> On Sat, Sep 19, 2020 at 12:40 PM <ch...@wbmfg.com> wrote: >>> >>> I don’t think I have ever seen a true +48 load. >>> >>> >>> >>> *From:* Ken Hohhof >>> >>> *Sent:* Saturday, September 19, 2020 1:29 PM >>> >>> *To:* 'AnimalFarm Microwave Users Group' >>> >>> *Subject:* Re: [AFMUG] -48 noob questions (mikrotik) >>> >>> >>> >>> Different situation, but I have several sites with 1100ahx4 powered with >>> +48, even though Mikrotik says they take -48. I suspect you will find the >>> same to be true on the CCR. >>> >>> >>> >>> Connect the – terminal to ground and the + terminal to +48, obviously >>> you don’t want to apply reverse polarity by trying to connect +48 to the >>> -48 terminal. >>> >>> >>> >>> I have some ccr1009 and ccr1036 but they are all AC powered, and I have >>> no ccr1072, so I can’t answer your exact question. >>> >>> >>> >>> >>> >>> *From:* AF <af-boun...@af.afmug.com> *On Behalf Of *TJ Trout >>> *Sent:* Saturday, September 19, 2020 2:19 PM >>> *To:* AnimalFarm Microwave Users Group <af@af.afmug.com> >>> *Subject:* [AFMUG] -48 noob questions (mikrotik) >>> >>> >>> >>> So I have a handful of ccr1072's that I want to run on our +48v plant, >>> mikrotik sells a '-48v telecom' power supply and they insist it's not >>> compatible with +48v. I ordered one for testing and both +/- input >>> terminals have no reference to chassis ground. I went ahead and applied >>> +48v and the power supply fired up (no smoke) and when measuring from >>> chassis ground to the input terminals I see no difference in potential. >>> >>> >>> >>> Before I shove this into a $3,000 router I wanted to see what I may be >>> missing here? >>> ------------------------------ >>> >>> -- >>> 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 >>> >>> ------------------------------ >>> >>> -- >>> 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 >>> >>> -- >>> 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 >>> >>> -- >>> 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 >> >
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