I agree with Chuck here. I personally don't like antennas spec'd at 6dB beamwidth.
On Wed, Apr 11, 2018 at 10:43 AM, <[email protected]> wrote: > 6 dB == half the range for an antenna if you are presuming a certain fade > margin. . > > Path loss = 96.6 + 20 log F + 20 log D > F is frequency in GHz, D is distance in Miles. > > If you say 1 GHz (for simplification) and 1 Mile path loss is 96.6 dB: > > At two miles it is 102.62 dB. > > At 3 dB down the range has decreased by 70% > > I think a beamwidth showing 70% to 100% range is more useful and honest > than 50% to 100%. > In other words, 3 dB down in receiver voltage is within the normal daily > fluctuations. > Not going to make or break a connection. > > 6 dB down is significant and could cause trouble. > > > *From:* Mathew Howard > *Sent:* Wednesday, April 11, 2018 9:29 AM > *To:* af > *Subject:* Re: [AFMUG] Rfelements > > I'm not sure if the RF Elements horns are rated at 3db or 6db, but I know > RF Elements list the beamwidth at both points for their normal sectors > (which is the best way to do it, if you ask me). It seems to be a lot more > common these days to use the 6db beamwidth for marketing purposes, but I > think there are actually some valid reasons for doing that - if the > manufacturer is recommended that you use antennas that are 90 degrees at > -6db, rather than -3db for an ABAB deployment, for example (which is the > case, with some of them, if I remember correctly), then it makes sense to > sell those as a 90 degree antenna, so that the people that don't bother to > check things like that don't buy the wrong antenna. > > On Wed, Apr 11, 2018 at 10:21 AM, <[email protected]> wrote: > >> Speaking generally here, not about this product specifically: >> >> >> A 30 is a 30 at some dB down from peak. Most reputable antenna >> manufacturers cite the beamwidth at the 3 dB down points on each side of >> the main lobe. That is called HPBW or half power beam width. >> >> Some go out farther to the 6 dB point to make their beam width seem wider >> than their competitors. Personally I believe that is false advertising. >> But I am sure they do not share my opinion. >> >> Look at the type of beamwidth. Should state how many dB down somewhere >> on the spec sheet. >> >> Other than that, horn antennas are very well characterized. They are >> used as lab standard calibration antennas. Other than the point where they >> choose to specify the beamwidth I think you can totally trust the specs. >> >> *From:* Steve Jones >> *Sent:* Wednesday, April 11, 2018 9:01 AM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] Rfelements >> >> so if im getting the right feel, here, I CAN trust these spec sheets? a >> 30 is actually 30 and not 90? FB is real? >> Ive had two in play on EPMP1000 for some time but i keep pulling them and >> moving them elsewhere because of changes, so Ive never had one up long >> enough to see. I have use case for narrower patterns and more APs at some >> sites because the uplinks are getting more interference than id prefer, my >> only other option is to add the secondary antenna on the 2000, im not a fan >> of adding windload with no net capacity gain >> >> On Wed, Apr 11, 2018 at 9:57 AM, Steve Jones <[email protected]> >> wrote: >> >>> we have a substantial garbage dump >>> >>> >>> On Wed, Apr 11, 2018 at 9:08 AM, Jaime Solorza < >>> [email protected]> wrote: >>> >>>> There's mountains near Steve's WISP footprint? >>>> >>>> Jaime Solorza >>>> >>>> On Wed, Apr 11, 2018, 7:45 AM Mike Hammett <[email protected]> wrote: >>>> >>>>> You have that the other way around. A horn would be ideal in a >>>>> mountain area. >>>>> >>>>> >>>>> >>>>> ----- >>>>> Mike Hammett >>>>> Intelligent Computing Solutions <http://www.ics-il.com/> >>>>> <https://www.facebook.com/ICSIL> >>>>> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> >>>>> <https://www.linkedin.com/company/intelligent-computing-solutions> >>>>> <https://twitter.com/ICSIL> >>>>> Midwest Internet Exchange <http://www.midwest-ix.com/> >>>>> <https://www.facebook.com/mdwestix> >>>>> <https://www.linkedin.com/company/midwest-internet-exchange> >>>>> <https://twitter.com/mdwestix> >>>>> The Brothers WISP <http://www.thebrotherswisp.com/> >>>>> <https://www.facebook.com/thebrotherswisp> >>>>> >>>>> >>>>> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg> >>>>> ------------------------------ >>>>> *From: *"Sean Heskett" <[email protected]> >>>>> *To: *[email protected] >>>>> *Sent: *Tuesday, April 10, 2018 10:49:19 PM >>>>> *Subject: *Re: [AFMUG] Rfelements >>>>> >>>>> I Totally agree with josh. >>>>> >>>>> They have a specific purpose so if you can deploy within those >>>>> parameters they are great. >>>>> >>>>> Unfortunately our area isn’t conducive to that type of deployment >>>>> because of terrain. In the mountains you need antennas with a wider >>>>> vertical beam because your towers are on mtn peaks and some clients are >>>>> same height as the tower and other clients are on the valley floor. It’s >>>>> hard to use a spot beam to cover all that. >>>>> >>>>> In the Midwest or other flat areas I could see them being useful to >>>>> spot beam the population centers. >>>>> >>>>> -Sean >>>>> >>>>> >>>>> On Tue, Apr 10, 2018 at 8:29 PM Josh Reynolds <[email protected]> >>>>> wrote: >>>>> >>>>>> They are great for stuff like 30/40Mhz wide, gps sync, put 4-6 on a >>>>>> pole in a subdivision or on a tower leg kinda thing. >>>>>> >>>>>> >>>>>> If anybody thought they were for something else (ie long range), they >>>>>> didn't read the data sheets. >>>>>> >>>>>> Lightweight, low size, low wind load, perfectly circular pattern - >>>>>> great spot beams. Good F/B ratio. >>>>>> >>>>>> On Tue, Apr 10, 2018, 9:12 PM Robert <[email protected]> wrote: >>>>>> >>>>>>> I recently did a couple of tests with RF horns. I was hoping for a >>>>>>> lot >>>>>>> and was disappointed. I was hoping that they could be colocated >>>>>>> closer than regular sectors that I use and the crosstalk signal >>>>>>> levels >>>>>>> were just about the same as the shielded sectors. As far as the >>>>>>> signals at the CPE's they were pretty good but not amazingly better >>>>>>> for >>>>>>> as small as the target area got reduced to. >>>>>>> >>>>>>> On 4/10/18 6:43 PM, Steve Jones wrote: >>>>>>> > Can i get some non fanboy real world on these guys? Btw, i hate >>>>>>> facebook >>>>>>> > groups almost as much as dslreports or the ubnt forums, this is >>>>>>> > literally the only place to get legitimate product info. >>>>>>> >>>>>> >>>>> >>>> >>> >> >> > >
