Recommended Antennas for use with Bullet M

[pnolan1069]

What is the consensus for a good & cost effective antenna for the Bullet M, used as a BackHaul.

For my needs I will be using them for appx. 7-15 mile P2P links. But feel free to talk about any antenna/sector/omni's that will be recommended for other uses.

In the past I have only used Motorola Canopy which integrates everything into a propiatary package

[WHT]

For backhauls, use a 28 dBi antenna. Not so much for the gain, but the narrow beamwidth. Wire grid antennas are under $60.

[pnolan1069]

Thanks for the responce.

Pac's selection is

GD5 Series (Wire Grid)
21dbi - 10deg h. beamwidth
25dbi - 6deg h. beamwidth
28dbi - 4deg h. beamwidth

DA Series (Solid Parabolic)
38-29dbi 2' - 6deg h. beamwidth
31-32dbi 3' - 4deg h. beamwidth

HD-DA Series (Solid Parabolic)
29dbi - 6deg h. beamwidth
32dbi - 4deg h. beamwidth

Echo Series (Small Form Factor) [es58-17]
17dbi - 25deg h. beamwidth.

Do i just want the narrowest beamwidth in most cases for BH?
The Echo Series is only $40, but looks "pretty" -- it also has a very large horizontal beamwidth, and only 17dbi. Obviously that model is not a good candidate for long distance backhauls. Do you, however, think it would be good for < 1mile backhauls? or does the 25 h. beamwidth stear you away from using it as any kind of BH?

[WHT]

I tested several antennas.

At the head end I have http://www.l-com.com/item.aspx?id=10041 27 dBi 6º H and 9º V, its 24" x 18"

At the tail end I have http://www.streakwave.com/Itemdesc.asp?ic=GD53-28&eq=&Tp= 28 dBi 4º H and 5º V, its 36" x 24". it has a tighter beamwidth and it "filters" out another 5.8 Gig omni five miles to the north to the point that I can use the same channel.

Even thought the second antenna has only 1 more dB of gain, it has a 2º tighter beamwidth which makes a difference.

http://whtonline.com/Team_Ubiquiti/test_grids_1.jpg
http://whtonline.com/Team_Ubiquiti/test_grids_2.jpg

[anthony24x]

That omni looks like it has a bullet hanging from it ;)

[WHT]

They all have Bullet M5 units.

The lower two antennas (with the radome enclosed feed points) have mounts that are offset and you can screw a Bullet into the back.

The top antenna lacks the offset and required a pigtail feed.

I'll get some pictures and Streakwave part numbers for the recommended antennas.

[Dave.D]

For my point-to-point 12Km 5Ghz Bullet link,
I used Poynting 30dbi grid antennas. Results
were excellent: high gain, tight beam pattern.

I also bought one of those 'welded wire' antennas WHT
shows, and I replaced it immediately. Paint had
chipped off even before I assembled it, and the
wires were attached with crude weld lumps.

Many of the wires were bent, and the mount is
galvanized steel instead of aluminum plate.

Yep, Poynting is hard to find, and it costs slightly
more, but IMHO it's really worth it. Dave

[WHT]

Paint had chipped off even before I assembled it, and the
wires were attached with crude weld lumps. YUCK...Do you know the manufacture? Model number" Distributor?

[Dave.D]

Pac Wireless GD5W-25P; complete with a dinky
tin-can retro-reflector clip-on for 0.5db gain.

Streakwave: nice folks!

Poynting uses a cast aluminum grid, feed 'horn'
with about 5x the GD5W pickup area, double
U-bolt clamp with aluminum bracket.

To be fair, the Poynting is 30dbi; a closer match
would be the GD5W-28P. But still welded steel
wires, and--because it's one piece--is oversize,
and costs an enormous amount to ship.

Poynting bolts together along a center overlap. Dave

[WHT]

Pac Wireless GD5W-25P; complete with a dinky
tin-can retro-reflector clip-on for 0.5db gain. I was sent the 28 dBi 36"x24".

Three had the enclosed reflector in a mushroom radome. One was bad, and I didn't test the other two. The pigtailed feed horns have the snap on reflector. I left off the reflectors (the only add one or was it one-half dB gain), because they appeared to be not have a really tight mount to keep alignment. On the other hand, that might not make that much difference compared to shielding it from other antennas.

I'll do some more test over the week.

[Dave.D]

Between the Pac Wireless 24dbi and the Poynting 30dbi,
I got what looked like 8dbi improvement in the signal.

I also got a much tighter beam (which you'd expect).

I didn't bother with the clip-in retro-reflector either. I
won't bother with the entire antenna for future installs! Dave

?Mushroom radome enclosing the grid? Never saw that.

[WHT]

Look at the pictures of the three grids, the lower two have a mushroom head, and the top one has the exposed reflector.

[rconaway]

Here is our Bullet 5M installation with a few NS2's below it:


http://picasaweb.google.com/lh/photo/Kjkkb5auHleziDqarj6rAA?feat=directlink

http://picasaweb.google.com/lh/photo/yguhrIBCyBh4cBpUaMOCuQ?feat=directlink

http://picasaweb.google.com/lh/photo/_EZsCMv-XuTG8SFMQJKEnA?feat=directlink

[Headbang]

I have tested with and without horn reflector, the only notable difference was isolation. Without the reflector I was picking up more adjacent systems. With the reflector I saw less noise. It seems to make sense, the horn is a dipole antenna, the reflector shapes the beam to reduce side lobe pickup.

[Dave.D]

Headbang, are you talking about that dinky little
aluminum clip-on?

Maybe it does something, but the feed dipole is
so tiny, anything might be an improvement. Dave

[WHT]

Yeah...thsoe dinky clip ons. They only increase the gain by half a dB, but they significant;y reduce the side lobe, say like a AP that is 45 º off to one side.

[mobilexpert]

@rconaway

highly professional, no other comment.
i admire such instalations, with quality antenna holder
and everything fitted-in-place.

b.r.
Alexandar

[WHT]

that dinky little aluminum clip-on? I haven't bothered putting them on as they don't mount very securely and I was concerned they would misalign the pattern, but when I started thinking about the geometry of the signal, it doesn't matter as it is still going to be a point source.

So we tested one with the dinky metal reflector in place and it does improve the side lobe rejection by about 10 dB, however that was just a quick and dirty test from my main backhaul that can see a lot of other APs and backhauls in many directions in the distance. I'll do some more testing in a more controlled environment where my tower sites are hidden behind some hills.