I’m just not going to put a hole in someone’s brand new metal roof, most homeowners won’t let us anyway. I’m talking about the shiny stuff in bright colors like you see on store and bank buildings, not the cheap sheets of tin they put on barns and garages.
Secondary concern unless you can mount on the edge is RF reflections off the roof. From: Af [mailto:af-boun...@afmug.com] On Behalf Of Josh Reynolds Sent: Wednesday, December 21, 2016 5:22 AM To: af@afmug.com Subject: Re: [AFMUG] Cambium 450 can signal be too hot? Explain the roof thing. I've personally done hundreds of satellite and wisp installs on metal roofs. I know wisps that ONLY install on metal roofs. Use proper lags, proper multi-lag foot pads, a good impact driver, and a butyl based sealant. Have decent insurance. On Dec 20, 2016 2:44 PM, "Ken Hohhof" <af...@kwisp.com <mailto:af...@kwisp.com> > wrote: In this case it’s 3.65 and at the SM due to using a dish. Long story behind this install, but it’s a grain elevator where we ran into problems with the belt housing obstructing one of the 4 APs and we didn’t get it in before harvest and then January came early and of course some guy calls wanting an install that should be on the missing sector but only 13 degrees beyond the 90 degree coverage for the neighboring sector. So rather than put him on the old 2.4 FSK we used a dish and 3.65 on the adjacent sector. Oh, and he neglected to mention he had put a metal roof on his ranch house so the installer had to put the dish lower than I like. No way we’re lagging through a metal roof unless it’s on a crappy barn. Bottom line is we’re only getting 4X and I’m trying to speculate what happens when we get the missing sector up, if it will pop to 8X or still be poor. It doesn’t sound like too high signal level is the cause of the problem. There are several other possibilities, I guess we won’t know until we put up that 4th AP which won’t be until nicer weather. From: Af [mailto:af-boun...@afmug.com <mailto:af-boun...@afmug.com> ] On Behalf Of George Skorup Sent: Tuesday, December 20, 2016 2:17 PM To: af@afmug.com <mailto:af@afmug.com> Subject: Re: [AFMUG] Cambium 450 can signal be too hot? ...at the cost of somewhat high probability of interfering with the opposite sector on the same freq. Been there, done that. Note than -52dBm is the default SM target receive level for SM Tx power control. I usually try to back this off to -55 or -57. And yes, I have short range SMs receiving at -45 to -50dBm. These will sometimes see the opposite sector. 30+dB of f/b ratio is great, but in this instance, it's not enough to achieve 256QAM. So you need to be very careful about what you're doing with customers close to sites. Some of these we've moved to an omni (yeah I know) at 5.4 dedicated to short range customers. On 12/20/2016 1:58 PM, Matt Mangriotis wrote: -55 dBm is a perfectly acceptable target level.� In fact, sometimes, you�ll want to set the target slightly higher (like -52 dBm) to overcome higher noise levels.
