I would be very surprised if you couldn’t use the dual slant yagi at the SM and a V/H sector or (shudder) omni at the AP. You could open a ticket with Support or post on the Cambium community. But if 2.4 and 3.65 can do it, why would 900 lack this capability? Why would a Dalmatian not have spots?
From: Af [mailto:[email protected]] On Behalf Of George Skorup Sent: Tuesday, November 22, 2016 5:19 PM To: [email protected] Subject: Re: [AFMUG] Dual-slant 900mhz omni (for PMP450) ordering group It's not as simple as taking the slant adapter off of the Cambium yagi. The adapter is threaded. You'll need slightly longer bolts and nuts to convert it to H/V. Ideally, I'd like to leave them as slant and get away with a H/V omni during site conversions. Then there's no going back to the customers after swapping to Cambium OEM slant sectors. What we could do right now if we really wanted to, is use an Antel h-pol and a separate v-pol omni like L-com/Hyperlink or something like that. I know Ben Royer has done that. I think it was an MTI diving board though, and whatever v-pol omni. On 11/22/2016 4:56 PM, Mathew Howard wrote: I'm pretty sure the 900mhz 450i can do the phase thing... the 3.65ghz PMP450 definitely can (the high gain integrated thing is H/V, but all the other 3.65ghz is slant, so it does work), so it'd seem pretty odd if these couldn't. I did do some testing with mixing H/V and slant antennas, and it seemed to work fine, but I didn't really do enough testing to know for sure. It looks like you can change the Cambium yagis to H/V pretty easily (theres a metal piece the holds the mount to the antenna at a 45 degree angle, that looks to be removable... haven't actually tried it though). Tower loading is definitely a problem with these things... so far all of our deployments have only been one or two sectors, because we usually don't need nlos coverage in all directions anyway, but I certainly wouldn't want four of them on most of our towers. Itelite makes a little (closer to the size of a normal 2.4ghz sector) 11dbi dual polarity H/V sector that could somewhat help with that, if they work half way decently... they're not exactly anywhere near the same quality as the Cambium sectors, and I'm assuming they don't have good enough F/B ratio to do frequency re-use, but they are nice and small and I'm hoping they'll be usable for some stuff. We have one of them up, but I haven't had time to do anything with it yet, so I don't know how well it's going to work. On Tue, Nov 22, 2016 at 1:45 PM, George Skorup <[email protected] <mailto:[email protected]> > wrote: The scenario I have at many 900 sites is >15-20 customers using 4x90 ABAB on FSK. There is no other option. 900 is the only thing that works. And I'm already using 16MHz. The top of the band is hosed with paging. I might be able to sneak a 5MHz channel in somewhere, but it will depend on the site. The next problem is tower loading. I already have four sectors. Adding another four of the Cambium OEM is unpossible. So if I can have an omni to get the site converted to 450i, take the FSK sectors down and put 450i sectors in their place and then take the omni down. That Alpha is hugemongous, but is dual slant. The KP will be H/V. So how would the SM handle being in a mixed H/V and slant environment? Can the 900 450i do the phase thing? The final problem which could make this a big waste of money is the smart grid rollout that we will see in the next year or two. If I get FSK speeds out of the 450i after they turn it up, that's pretty much suicide. I would club baby seals for some TVWS gear that works. On 11/22/2016 9:12 AM, Kurt Fankhauser wrote: You are wasting you time with omni's on 900mhz. So your sacrificing a lot of gain to get 360 degree coverage which in turn will result in higher overall noise floor and lower signal when this 450 product really starts to shine you need 25db+ SNR at the client side to get the higher modulation connections. So even if you got the Omni you'd going to be lucky to get 8-10db SNR to the client which means your only going to be running at 2x speed and getting 10mbps download which will probably be intermittent. I had a lot of omnis on FSK 900 and I can tell you that after having used the cambium slant sector on 450 I am a firm believer in sectors only for 900 from here on out. I have connections that are 3-4 miles out running 10mhz channels and getting 40mbps down/10mbps up. You will never get that with an Omni unless you have LOS and if you have LOS then why aren't you using another frequency band? On Tue, Nov 22, 2016 at 2:03 AM, Colin Stanners <[email protected] <mailto:[email protected]> > wrote: I've been looking for dual-slant 900mhz omni options that would allow lower-cost PMP450 900mhz deployment on middle-of-the-woods towers where there are only a small number of customers (and low noise). I know that "omnis suck compared to sectors", but having nothing at all sucks more. Due to the difficulty of designing dual-slant antennas and the small market, options are very few. Commscope has the CH360QS, only 5dbi gain at ~900mhz... and it's a cellular base station omni with all the fancy doodads: 1800-2200Mhz band that WISPs can't use, internal GPS antenna, internal diplexer, remote-controlled signal tilt on the upper band, etc. At $3500 per antenna I hope that it makes your breakfast too. Alpha has the best design that I found at present, the AW3464. ~7dbi gain http://alphaantennas.com/products/small-cells/aw3464/ . It's ~$1200 USD which is still inexpensive compared to any other NLOS options. But currently those antennas cannot be bought - I spoke with Crossover Distribution and Alpha, they haven't received enough POs to make a production run, need 50 orders at a bare minimum. So if anyone else is really interested in one or more of these antennas, ready to buy for sure if they are available, e-mail me "If available, I will buy x number of the Alpha AW3464 at $1200/USD each from Crossover." and I'll make a list, once it hits 50+ antennas I'll speak with Crossover and see if it can happen.
