Yeah, the beamwidth too, forgot about that. And beamwidth is proportional to gain. Gain is proportional to dish diameter.
From: Hardy, Tim Sent: Tuesday, November 08, 2016 6:08 AM To: af@afmug.com ; af@afmug.com Subject: Re: [AFMUG] Class A and B antennas A couple of clarifications: The VHLP800 (800 mm) is obsolete and no longer available - it was replaced by the VHLP3-11W (3'). There was a lot of discussion about the difference between A and B being sideline suppression and F/B and that certainly is true, but the main difference between a 2', 2.6' and 3' is the main beam gain and beam width. In order to meet Cat A at 11 GHz, the minimum size antenna that meets either of these requirements is 2.6'. There's not a demonstrable difference in co-polar patterns between these smaller antennas (Sentinel excluded of course) and the ability to coordinate them (or not) depends on congestion and what's within about +/- 30 degrees of main beam. There are major and demonstrable differences between differing manufacturer's models of the same size. As someone pointed out, the RW HP2-11 may be cheaper than RFS or Commscope, but the cross-pol patterns pale in comparison and we have seen many instances where a VHLP2 will coordinate where the HP2 will not. Anyone that licenses a 2' or Cat B antenna needs to understand the liability of doing so. In congested areas, it is certainly a risk that you may be required to upgrade to a Cat A if another user cannot coordinate around your Cat B antenna. All costs associated with this upgrade would be your responsibility. Finally, I could mention that there are larger very high performance (ultra-high) antennas (F/B > 80) that allow significant frequency re-use. Take a look at Mt San Miguel near San Diego where almost every path is using multiple 11 GHz frequencies and ultra-high performance antennas. Get Outlook for iOS _____________________________ From: Rory Conaway <r...@triadwireless.net> Sent: Tuesday, November 8, 2016 7:35 AM Subject: Re: [AFMUG] Class A and B antennas To: <af@afmug.com> And availability. The B11’s were available almost a year ago. Here is another thing, the B11’s can get up to 480Mbps of real throughput in a 40MHz channel. Rory From: Af [mailto:af-boun...@afmug.com]On Behalf Of Josh Reynolds Sent: Tuesday, November 8, 2016 5:05 AM To: af@afmug.com Subject: Re: [AFMUG] Class A and B antennas Just $1,200+ more per end than an AF11x. You could buy a pair of Cisco SFPs for that savings! At list price! ;) (Yes, I understand business case vs product cost, just ribbing you a bit.] On Nov 8, 2016 6:00 AM, "Mike Hammett" <af...@ics-il.net> wrote: I haven't bought B11s, just while scouting for options, I *COULD* do B11s. I could also swap them out later for something else like an AlfoPlus2. Why would I do a B11? Cheapest 11 GHz link with an SFP. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP -------------------------------------------------------------------------------- From:"Bill Prince" <part15...@gmail.com> To: af@afmug.com Sent: Monday, November 7, 2016 10:51:11 PM Subject: Re: [AFMUG] Class A and B antennas +1 Inquiring minds. bp<part15sbs{at}gmail{dot}com> On 11/7/2016 8:47 PM, Sean Heskett wrote: If you are in a congested RF environment why on earth would you waste the spectrum on a B11? It only does 256QAM On Mon, Nov 7, 2016 at 6:42 PM Mike Hammett <af...@ics-il.net> wrote: *nods* I asked about going from a 3' to a 6' SHP dish, no go. That said, I've got a couple paths in HFT central where I can still do B11s. :-) ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ---------------------------------------------------------------------------- From:"George Skorup" <geo...@cbcast.com> To: af@afmug.com Sent:Monday, November 7, 2016 7:39:31 PM Subject: Re: [AFMUG] Class A and B antennas My finger clicked send before my brain. Interestingly, a RadioWaves HP2-11 has 60dB f/b ratio and is a Cat B. While a HP3-11 has 62dB f/b and is Cat A. The VHLP800-11 has 59dB f/b and is Cat A while being only 3" smaller in actual diameter vs the HP3-11 (35.5" for a "2.5" foot antenna, vs a 38.4" 3 foot). But a bit weaker f/b ratio than a HP2. Both are shrouded. I don't get it. I think there may be something else like main lobe beamwidth, too. The problem with all this Cat A vs B stuff is it really doesn't matter anymore in congested areas. I had Liz look for a 56MHz channel on a path. She said nope. I said, OK, what about changing the 2' end to a 3'. She still said nope. Polarity, antenna size, etc., nothing mattered. Out of channels is out of channels. Good luck with those funky B11's. On 11/7/2016 7:09 PM, Mike Hammett wrote: Yes. Not a size requirement, just a suppression requirement. It's just what size of antennas normally meet those requirements. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP -------------------------------------------------------------------------- From:"George Skorup"mailto:geo...@cbcast.com To: af@afmug.com Sent: Monday, November 7, 2016 7:08:11 PM Subject: Re: [AFMUG] Class A and B antennas IIRC, the classes are about front to back radio and sidelobe suppression. On 11/7/2016 6:45 PM, Mike Hammett wrote: 2.6' in 11 GHz. I forget who. ----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ------------------------------------------------------------------------ From:"SmarterBroadband"mailto:li...@smarterbroadband.com To: af@afmug.com Sent: Monday, November 7, 2016 6:34:03 PM Subject: [AFMUG] Class A and B antennas Does anyone make a 2 foot Class A antenna for 11 GHz? Or is 3 foot the minimum. Does anyone make a 1 foot Class A antenna for 18 GHz? Or is 2 foot the minimum. Is there a minimum distance for a 11 GHz link? Thanks Adam
