There are dual slant antennas for cellular 900 but the trend seems to be toward multiband something like 900/1900/2500 for LTE.
From: Adam Moffett Sent: Wednesday, October 14, 2015 12:09 PM To: [email protected] Subject: Re: [AFMUG] PMP 450i 900 MHz SM One problem I see is V and H antennas are common and cheap, whereas dual slant 900mhz antennas are not. I think initially the only available antenna options are going to be whatever Cambium sells. I wonder if somebody could make an enclosed dual pol yagi that could be rotated to a 45 degree orientation. On 10/14/2015 1:05 PM, Mathew Howard wrote: Yep, the integrated SM was H pol, which was part of the reason I went with horizontal for all of ours... and pretty much everything else that I've seen on 900mhz is V pol. I think it does make sense to go with slant for a 900mhz MIMO system to equalize the two paths. On Wed, Oct 14, 2015 at 11:49 AM, George Skorup <[email protected]> wrote: We're all H pol on our 900. Wasn't the old integrated SM was H pol as well? Nearly all of the SCADA stuff out there is V pol. Slant gets you 3dB from H or V polarized systems. That's not a whole lot of rejection. Like I said before, slant should get you better equalization on the two paths so that it's not constantly running MIMO-A. But if it's so noisy that you get maybe 10dB SNR, OK, so that'll be 1X MIMO-B, basically not any better than FSK. On 10/14/2015 11:24 AM, Daniel White wrote: I’m sure Matt will post in detail their reasoning for dual-slant next week, but to sum up it was to get rejection from V-Pol and H-Pol signals since the band is probably 100% linear polarized. I was shocked to hear Matt tell me though that many FSK customers are using Vertical Polarity. I thought everyone did Horizontal, but maybe that was just the way my WISP did it. Thank you, Daniel White [email protected] Cell: +1 (303) 746-3590 Skype: danieldwhite Social: LinkedIn: Twitter From: Af [mailto:[email protected]] On Behalf Of George Skorup Sent: Tuesday, October 13, 2015 3:49 PM To: [email protected] Subject: Re: [AFMUG] PMP 450i 900 MHz SM I would rather have the style we're used to: MCX to N-male pigtails coming out of the bottom of the case. However, if you saw their dual-slant yagi which has two RP-SMA connectors on it and a provision for mounting the SM to the back of it, I can see why they're coming out of the top. The folded dipoles do not have a radome. They will ice up and be worthless. Again, I would much rather have an integrated panel. Their choice to do dual-slant.. we'll see how that goes. Makes all existing antennas obsolete. I'm a little disappointed since it'll be 10x as hard to convert a 4x90 FSK site. The -6dB 65 degree sectors drive me nuts. There's 26MHz to play with and you can count on the top being trashed, then cordless phones and baby monitors all throughout. There's no way in hell we could ever use six sectors at a site. 90 degree sectors allows you to move around in the band a little bit. So I hope they come up with some 90's. On 10/13/2015 5:24 PM, Brian Sullivan wrote: Is the design of the module final? I'd rather see integrated cables or those pesky RF connectors underneath a cover to avoid water. Will Cambium be including RF cables with each SM? Also, the specs say 100M throughput in a 20MHz channel. What is the throughput running in 1x or 2x? 450 + ePMP love child. -------------------------------------------------------------------------- This email has been checked for viruses by Avast antivirus software. www.avast.com
