madness we are a little better than the target after fine alignment. at one point we had the 4' side pinting to the ground abot 100 yards out ant it still had about a -80 on the bnc readout
On Fri, Dec 12, 2014 at 11:36 AM, Ken Hohhof via Af <af@afmug.com> wrote: > > Yeah, it was so considerate of AT&T to leave that dish up there when > they sold off the site, only needed to be re-aimed about 2 degrees to go > where we wanted. And they built a platform to stand on while aiming it, > that was awfully nice of them. And they left the flexible waveguide down > to the shelter. I’d really hate to think about hanging a new 12 ft dish > ourselves and running waveguide to it. And it’s an Andrew parabolic, not > the old WE horns, so we don’t have to worry about water getting into the > waveguide and freezing. It doesn’t even look like anyone has been using > the lightning bolt logo for target practice. Life is good when someone > abandons nice stuff you can use. > > > *From:* Hardy, Tim via Af <af@afmug.com> > *Sent:* Friday, December 12, 2014 11:18 AM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] aligning bigger antennas on short paths > > > HPBW for a 12 ft dish at 11.2 GHz is 0.5 degree. > > > > *From:* Af [mailto:af-boun...@afmug.com] *On Behalf Of *Ken Hohhof via Af > *Sent:* Friday, December 12, 2014 11:17 AM > *To:* af@afmug.com > *Subject:* Re: [AFMUG] aligning bigger antennas on short paths > > > > Nope, a 4 ft dish in 11 GHz should be pretty narrow, a few degrees and you > should be into a deep, deep null. Take a look at the beamwidth or pattern > for your antenna. It should be similar to an 8 ft dish in 5.x GHz. > > > > We once used an existing 12 ft dish for an 11 GHz link and I kept having > to tell the tower guy he was not going to be able to eyeball it. The > beamwidth was something like 1 degree if I remember right. He ketp getting > nada for signal until I made him slowly sweep the azimuth. > > > > > > *From:* That One Guy via Af <af@afmug.com> > > *Sent:* Friday, December 12, 2014 9:50 AM > > *To:* af@afmug.com > > *Subject:* [AFMUG] aligning bigger antennas on short paths > > > > Weve never gone above 2' > > we finished installing our 11ghz link yesterday and had the antennas rough > aligned, one side is 3' one side is 4'. I expected the tighter patterns > would make it harder to find the initial link but they actually linked up > right off the bat and it was right on the projected power levels. > > This is only 10 miles, so we have visual on the path. > > We did a little rough alignment yesterday, and will do the fine alignment > today. when we we roughing it there was a good amount of travel on the > antenna (4') side we were on and only a couple db change. do larger > antennas on such a short path give you a little more leniency in alignment > or something? we will do full horizontal and vertical panning today to make > sure we arent in side lobes, just curious is there is more slop in this > scenario. > > > > -- > > All parts should go together without forcing. You must remember that the > parts you are reassembling were disassembled by you. Therefore, if you > can't get them together again, there must be a reason. By all means, do not > use a hammer. -- IBM maintenance manual, 1925 > -- All parts should go together without forcing. You must remember that the parts you are reassembling were disassembled by you. Therefore, if you can't get them together again, there must be a reason. By all means, do not use a hammer. -- IBM maintenance manual, 1925
