I built one of these to try out

[Mark]

http://neofast.net/users/mark/pics/wp/apviews/waveguide1.jpg

I don't know what the true gain is, and haven't had the time yet to test adn compare to known values, but it seems to have a LOT of gain.

It is HPOL, and appears to be about 120 degrees X 5-8 degrees, and produces one heck of a signal. I can associate with a 14 db panel at 4 miles, with trees in the way at a solid 11M. The radio is a 5004x running in "g" mode set at 17 dbm. Client is "b" mode.

[mp3turbo]

hello mark,

I'm interested in construction - will you be so kind and provide details how you did it? Or probably some URL with instructions... BTW, what was the cost of it?

thnx, mp3turbo.

[Mark]

I have a spreadsheet the calculates the whole thing for you.

Total cost for one antenna is about 50 bucks and that includes the metal, miscellaneous hardware, the N female connector, etc, and that's probably a bit on the high side. One person can build this in an afternoon, using a router, precision measuring tools, scribe, drill, and file. You'll need some smaller aluminum sheeting along with a pop rivet tool to finish it off on the ends.

I bought 2 X 4 inch aluminum tubing from here: http://www.onlinemetals.com/

If you want the spreadsheet, email me. I found it online, but can't recall the URL.

[lonnie]

What did you use for cutting the slots? I would be interested in the spreadsheet if you want to forward to me as well.

[Mark]

The slots were first scribed carefully, then drilled, and then made close to size with a normal router. Then, the slots were squared to the scribe lines by filing.

Here is the link to the spreadsheet.

http://neofast.net/users/mark/pics/wp/WaveguideCalculator.xls

Look for the author's comments in the spreadsheet.

Also, read about waveguides in general by looking up Trevor Marshall's website.

[jlawrence]

obviuosly the only thing that actually matter is how is performs.
I'd be interested in any comparisons with antenna's of know gain.
I reckon it might be worth a crack at building one of these.

[mp3turbo]

hi mark,

> haven't had the time yet to test adn compare to known values, but it seems to have a LOT of gain.

yeah, this is what we would like to know - please, post your findings when you will have this data available. BTW, there are no gain calculations in the spreadsheet - can anyone just estimate what does this beast stand for?

thnx, mp3turbo.

[ivosp]

I have made WaveGuide Slot antenna year ago. Work perfect for me. Real gain is about 15 dBi. More info at:
http://www.trevormarshall.com/waveguides.htm

[Mark]

Ivosp, this is a 16 slot, not an 8 slot like Trevor Marshall's design. It's more gain than his.

[funkywizard]

http://www.netgate.com/product_antennas.html

scroll down to "18 dBi Securawave 8 Slot Multibeam Antenna" and "21 dBi Securawave 16 Slot Multibeam Antenna" they claim 100 degree sector coverage for $250 or $325 respectively. I'm not sure how well these work but they look almost exactly like what you made.

[Mark]

yeah, these guys made it

http://www.securawave.com/Page2.html

You'll notice that mine has narrow slots and Securawave's and Trevor Marshall's both have wide slots.

These guys tried them all
http://members.iinet.net.au/~clark/FreeNet/Waveguide/

and you'll notice that thier results are sort of... unusual.

Now, the reason I haven't tested anything yet, is that I am just in the startup phase for a WISP. I don't have customers yet, and I don't have CPE stuff sitting around to play with - in fact, I'm broke.

However, I WILL be doing this very soon. I'm getting some antennas and CPE stuff soon, and when I do, I'm going to gauge the signal strength between this antenna and a 24 db grid.

If anyone wants to help by donating some stuff.. .hey, I'll put the time in to TRY it and give you the results ASAP.

[ivosp]

You can drill hole's on both sides and result is 15-16 dBi gain omni antenna.

[Mark]

Thats for an 8 slot antenna.

The 16 slot will be higher.

[funkywizard]

so these actually work as described then? It seemed kind of like a pipe dream to be getting 18db 100 degree sector antennas, since most sectors seem to max out at around 14db.

[Mark]

Let's just say that I"m impressed with it. Not that I have a lot of experience, but I can tell you that sector, even with the radio set to 15 dbm is the strongest thing out there by far in our area.

I can connect to it at 9 miles, with a 14 db panel, 30 degrees BEYOND the edge of the sector. It's weak, but working...

[go.fast]

so these actually work as described then? It seemed kind of like a pipe dream to be getting 18db 100 degree sector antennas, since most sectors seem to max out at around 14db.

I bought a couple of Pac Wireless waveguide H omni's. I replaced a superpass H omni with one of the waveguides and noticed a big improvement.
George

[funkywizard]

Let's just say that I"m impressed with it. Not that I have a lot of experience, but I can tell you that sector, even with the radio set to 15 dbm is the strongest thing out there by far in our area.

I can connect to it at 9 miles, with a 14 db panel, 30 degrees BEYOND the edge of the sector. It's weak, but working...

Thats pretty impressive. With the 16 vagi on fab corp connected to a 9db omni I could barely muster 70k/sec (an just a couple db below dropping altogether) at 5 miles los.

[mrmike]

Now, could you encased this antenna in a PVC pipe, to keep bugs, birds and water out of it? Has anyone tried?

[rbolduc]

Nope It becomes too heavy, you need 6" PVC, I used lexan plastic cut into 2 strips 3.5" x 42" If I remember right :) glued on with silicone. Worked with no problems for 1 year including a harsh winter with no water/bug/dirt problems. I upgraded to a Pac Wireless unit which uses some type of fiberglass tape no problems with that yet but it is 65' in the air though :lol:

P.S. make sure you get a test peice of plastic and put in in a microwave for a min or so. I put it in for 2 min and it didn't even get warm so it should not harm 2.4 wireless as a microwave runs at 2450

Reed