These are wtm4200. He told me the connector in the radio bonds + to ground at the radio. Could be wrong. I'm outside my wheelhouse anyway with this being our first direct dc radios.
On Mon, Sep 21, 2020, 10:00 AM Josh Baird <joshba...@gmail.com> wrote: > 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 >>> >> -- > AF mailing list > AF@af.afmug.com > http://af.afmug.com/mailman/listinfo/af_af.afmug.com >
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