Thanks Chuck, that's interesting stuff. Any thoughts on how the first one I posted is supposed to work? To me it appears like it's actually just a single antenna (well, 3 sectors) with two connectors on it instead of having distinct H and V pol parts... can that actually work?
On Fri, May 29, 2015 at 2:53 PM, Chuck McCown <ch...@wbmfg.com> wrote: > Spoiler alert: > > The slotted extrusion looks like a waveguide but in reality it is more of > a square coax. There is a center conductor running up the middle and it > is either shorted or open at the end. Generally it is printed on a PCB > rather than a wire but either will work. > > That sets up standing waves along the center conductor where the peaks > coincide with the horizontal steps in the slots. The peak of the > standing wave excites a current on the slot. The slot current then runs up > and down the vertical parts of the slot. > > A vertical slot radiates in a horizontal polarization. So that is the H > pol part. > The circuit boards on the sides are a series fed array of patches. That > is the V pol part. > The V pol part helps to circularize the H pol part because those types of > antennas have more of a peanut shaped pattern. > > The V pol is a bit less circular. > > *From:* Rory Conaway <r...@triadwireless.net> > *Sent:* Friday, May 29, 2015 1:08 PM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] Arc dual polarity omni > > > I didn’t see the waveguides in the picture. That’s what made me curious. > > > > Rory > > > > *From:* Af [mailto:af-boun...@afmug.com] *On Behalf Of *Mathew Howard > *Sent:* Friday, May 29, 2015 11:15 AM > *To:* af > *Subject:* Re: [AFMUG] Arc dual polarity omni > > > > In the interests of avoiding doing any real work, I opened up one of the > Arc 13dbi 2.4ghz dual polarity omnis... it seems pretty similar to every > other dual polarity omni I've seen, nothing like the 5ghz. > > > > > > > > On Fri, May 29, 2015 at 11:40 AM, Mathew Howard <mhoward...@gmail.com> > wrote: > > We have several of the 2.4ghz version and they seem fine. I've done a > little testing and the pattern seems pretty similar to the ubnt 13dbi dual > polarity omnis - I've also replaced a few other kinds of omnis (mostly > single polarity) with them and I didn't see any notable difference in > coverage. I'm not sure why the 5ghz is so bad... > > > > On Fri, May 29, 2015 at 11:35 AM, Glen Waldrop <gwl...@cngwireless.net> > wrote: > > That is quite horrible. > > > > I've got the Arc 2.4GHz 13dBi omni serving 17 rural customers, no > particularly strange issues like that, though now I'm thinking of testing > more thoroughly. > > > > > > > ----- Original Message ----- > > *From:* Mathew Howard <mhoward...@gmail.com> > > *To:* af <af@afmug.com> > > *Sent:* Friday, May 29, 2015 11:04 AM > > *Subject:* Re: [AFMUG] Arc dual polarity omni > > > > Yep, it is a triangle... the thing is the sectors appear to be about 15 > degrees each. > > > > On Fri, May 29, 2015 at 10:55 AM, Chuck McCown <ch...@wbmfg.com> wrote: > > I presume there is a third array that we cannot see arranged in a > triangle. This is essentially three sectors phased together. > > > > Our omni is much more of a true omni. > > > > *From:* Mathew Howard <mhoward...@gmail.com> > > *Sent:* Friday, May 29, 2015 9:34 AM > > *To:* af <af@afmug.com> > > *Subject:* [AFMUG] Arc dual polarity omni > > > > We have some ARC wireless 5ghz dual polarity omnis that I've suspected for > awhile are under performing, so I finally got around to swapping one for > sectors and found that was very much the case... connections pretty much > all improved - some by as much as 15db. out of curiosity I did some further > testing and found that by rotating the antenna the signal to a client about > a mile away would change by close to 15db, with it only being good at a few > pretty narrow points. > > So... I opened it up to see if there was an obvious reason it's so much > worse than the other dual polarity omnis I've used, and it is indeed very > different... I'm no antenna expert, but something seems very wrong with > this design. Why would they even make something that works that poorly? > > > > > > > >
