Chipping in here, To be fair to MT: AFAIK It's harder/more expensive to design 48V-input power supplies (the chips on most boards require some mix of 5.0/3.3/2.5V or other rails) than lower voltages. Of course 48V is desirable by users, because of lower cable loss, enabling longer runs. I had this debate with the MT people some time back, in favour of 48V. It seems there are far more 12-30V chipsets, and easier-to-implemet designs, than at 48V. Also, telco environments always have 48V (36-72 a common spec) But commercial pressures (people only buy high volumes at low price points) probably guided the "28V max non-isolated" decision.
Also, relevant point: Some boards out ther have **isolated** input PSUs. The RB532 and 112 for example. However, most boards don't. Well isolation costs money (read: custom-wound transformer, other components) but non-isolated designs are cheaper. Well that depends on your deployments - some environments cope with non-isolated roof/tower-top devices fine - and some don't. Important to consider that. I hope that comment is of help - Regards Stephen Patrick CableFree Solutions -----Original Message----- From: Travis Johnson [mailto:[EMAIL PROTECTED] Sent: 04 August 2007 19:13 To: WISPA General List Subject: Re: [WISPA] MT announces RB192 and RB333 Maybe someone can post the link to the FCC docs showing their certification? Also, you will notice their PoE only supports up to 28VDC now, rather than 48VDC like the RB532. They probably couldn't get the boards to pass FCC at 48V. Travis Microserv Butch Evans wrote: > On Fri, 3 Aug 2007, Travis Johnson wrote: > >> And even if they do, that doesn't make a complete radio system FCC >> compliant... only their board. > > No, but it is a GOOD first step toward creating certified systems. If > I were to try to build a certified system on the older boards, I'd > have to spend more money, because more tests would have to be run. > > FWIW, I'm not sure where the idea that they would put the sticker on > and not hold the paperwork. That's a bit over the top paranoia. > ---------------------------------------------------------------------------- ---- WISPA Wants You! Join today! http://signup.wispa.org/ ---------------------------------------------------------------------------- ---- -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- This email has been verified as Virus free Virus Protection and more available at http://www.plus.net -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
