That's a good point. I wish manufacturers would all put a graph in the specs showing the gain across the whole band... I've seen some that do (although I can't say that I remember which ones... ).
On Tue, Jan 23, 2018 at 9:47 AM, Adam Moffett <dmmoff...@gmail.com> wrote: > A difference that sometimes is not clear on spec sheets is you can't have > the same efficiency across all wavelengths. "5ghz" could mean from 4.9 to > 5.8 (or more in some countries). The antenna won't be equally effective > across a whole ghz of spectrum. > > You and I might test the same two dishes and you might say dish A was a > couple db better and I might say dish B was a few db better and the > difference might be that I'm using 5.1ghz and you're using 5.8ghz, so we'd > both be right about our respective dishes at our respective frequencies. > The spec sheet on both antennas might say "30dbi" and they're both right > because that's the peak gain at some point in the 5ghz band, but it needn't > be the same point between the different designs. The difference shouldn't > be more than a few db so most of the time we don't have to fret about it, > but if you're looking for the highest gain then it might matter. > > > ------ Original Message ------ > From: "Rory Conaway" <r...@triadwireless.net> > To: "af@afmug.com" <af@afmug.com> > Sent: 1/23/2018 12:45:58 AM > Subject: Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > So Chuck, what’s your opinion? Parabolic or reflector that the > manufacturers spec out at approximately the same gain? > > > > Rory > > > > *From:* Af [mailto:af-boun...@afmug.com] *On Behalf Of *Chuck McCown > *Sent:* Monday, January 22, 2018 8:16 AM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > > > Gain of a parabolic reflector: > > =10*LOG((0.55*((3.1415*Dia/Lamda)*(3.1415*Dia/Lamda))),10) > > > > .55 is the efficiency factor. Most of them range between .55 and .60 > > Diameter is in inches. Lamda is in inches. > > > > *From:* Rory Conaway > > *Sent:* Monday, January 22, 2018 7:08 AM > > *To:* af@afmug.com > > *Subject:* Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > > > If you are talking about the 2’ dishes, their gain in 5GHz is the same as > the KP reflector. We may test that but honestly, between the price > difference which is more than $100, the weight, and the complexity, it > would have to be significantly better and I doubt it is. > > > > Rory > > > > *From:* Af [mailto:af-boun...@afmug.com <af-boun...@afmug.com>] *On > Behalf Of *Mike Hammett > *Sent:* Monday, January 22, 2018 6:58 AM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > > > They still work down there, just lose a couple dB. Their better rejection > makes up for it. > > > > ----- > 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: *"Rory Conaway" <r...@triadwireless.net> > *To: *af@afmug.com > *Sent: *Monday, January 22, 2018 7:57:40 AM > *Subject: *Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > Most Jirous antennas aren’t good for under 5.4GHz though. We started > using them after being told more than 2 years ago they would have updated > nose cones shortly. I’m still waiting. > > > > Rory > > > > *From:* Af [mailto:af-boun...@afmug.com <af-boun...@afmug.com>] *On > Behalf Of *Mike Hammett > *Sent:* Monday, January 22, 2018 6:30 AM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > > > Jirous makes antennas with good patterns. > > > > ----- > 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: *"David Coudron" <david.coud...@advantenon.com> > *To: *af@afmug.com > *Sent: *Sunday, January 21, 2018 9:04:56 PM > *Subject: *Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > We love the KP Performance antennas for the CPEs, but haven’t used them > yet for backhaul. Have you been using them for that as well? We were > worried the wider beamwidth would catch too much other noise. Or maybe > that hasn’t been an issue? > > > > Thanks, > > > > David Coudron > > > > *From:* Af [mailto:af-boun...@afmug.com <af-boun...@afmug.com>] *On > Behalf Of *Rory Conaway > *Sent:* Sunday, January 21, 2018 8:56 PM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > > > Right now the best antenna we have tested at 30dBi has been the KP > Performance antennas. We will be testing the RF Elements antennas next. > > Rory > > > > *From:* Af [mailto:af-boun...@afmug.com <af-boun...@afmug.com>] *On > Behalf Of *David Coudron > *Sent:* Sunday, January 21, 2018 6:49 PM > *To:* af@afmug.com > *Subject:* [AFMUG] Arc Wireless 30 dBi vs RocketDish RD-5G30 > > > > We have traditionally been using the Arc Wireless 30 dBi 5 GHz parabolic > dish for our shorter backhaul links when using 5 GHz. The have been OK, > but we have a tough time getting them and the radomes from time to time. > We are in that situation again. They are priced quite competitively, and > seem to do the job, however we are looking for options since they are so > spotty to get ahold of. We have messed around with the Ubiquiti > RocketDish for CPE connectorized radios, but haven’t tried them out for > backhaul as of yet. The specs appear to be very similar and I expect > they’d perform about the same other than the N-Type vs SMA connectors. > Anyone have experience with both of these dishes? Or is there a better > alternative that we should be looking at in the $120 range (dish only)? > > > > Regard, > > > > David Coudron > > > > > >
