Good point about the power being on 1/2 and 3/6. I guess that makes it 802.3at Alternative A wiring. According to the schematic, 4/5 and 7/8 are wired straight through with no transformer. So gigabit compatible with only 2 transformers. Probably for non gigabit compatible, Alternative B is cheaper because you don’t need any transformers at all. And the 60-75 watt POEs use all 8 wires for data and power, so 4 transformers.
So confusing! I can’t find any wiring diagrams for the Cambium N000065L001B, but at 60 watts, I guess it must use all 8 wires for power. Hence the price? Something else I notice is the Cambium POE is rated for 0 to 40C, while the Phihong unit is rated –20 to +65C. Cambium tells you to use a PIDU for non controlled environment. Or Netonix or GIGE-POE-APC or Syncinjector. Still, AC powered POEs are handy for configuring radios on the bench, or like that case where I needed a POE at a customer’s office to power a SIP paging amplifier. From: George Skorup Sent: Monday, January 04, 2016 2:35 AM To: [email protected] Subject: Re: [AFMUG] 802.3at POEs It's cheaper at Allied: http://www.alliedelec.com/phihong-poe36u-1at-r/70124112/ Yeah, if you're not going to use the Aux port on the 450i, there's no reason to buy a 60W injector. Just keep in mind that this Phihong injector is power over the 10/100 data lines. And is - on 1&2, + on 3&6. It'll work perfectly fine with the 450i APs and 5GHz SMs. And obviously the Exalt ExtendAir G2. The 450i is awesome with the any pair power setup. The one thing I will say about this thing is that it runs a bit hot and if your hearing is decent, you can definitely hear the switcher whining away. On 1/3/2016 7:29 PM, Ken Hohhof wrote: I'm getting more and more equipment with 802.3at POEs, and I feel like I'm getting raped on the price if I get the POE from the equipment vendor. High price and minimal features. My Exalt G2 radios came with these really nice POEs that have diagnostic LEDs and tabs for wall mounting as well as rubber feet for desktop use. The only downside is they are kind of big, but that's not necessarily bad, that may help prevent overheating. It has LED indications for valid 802.3af and 802.3at signatures, as well as a flashing overload indication. I looked up the part number, expecting them to be expensive, but Digi-Key has a bunch of them in stock and the price is quite reasonable ($38 in single quantity). http://www.digikey.com/product-detail/en/POE36U-1AT/993-1088-ND/2384576 From the picture, this is also the POE that I should have gotten from CyberData to go with the SIP paging amplifier I bought, but instead they sent a cheaper L-Com POE that has just one dumb LED to show it is getting AC power. So I paid something like $64 for a $31 POE. The $100 Cambium POE for 450i is probably more than 36 watts in case you want to use the AUX port on the AP, but it lacks the nice mounting tabs and diagnostic LEDs. And 36 watts should be more than enough to power just the AP. So I’m inclined to just buy a bunch of the nice Phihong units and use them on everything. Am I missing something?
