Pringles antenna - allowable deviations?

10-01-2001

I'm trying to build a pringles-can directional antenna and am wondering how much I can deviate from the design (http://www.oreillynet.com/lpt/wlg/448). In particular, I'm having a hard time finding 1" washers with a 1/8" hole in the center. Does the size matter? I have some 3/4" washers with a 1/8" hole.....will they work?

I'm also wondering what it would take to make an omni-directional antenna - does the pringles can 'focus' the reception or is the design of the element the focusing factor. If it's the former, could I use PVC pipe instead of a pringles can and have the antenna be more omnidirectional?

On the 'original' pringles-can site (http://www.netscum.com/~clapp/wireless.html) there is mention of a di-pole antenna. It looks like a piece of wire a multiple of 1 wavelength (1 wavelength=4.84" (middle of 4.80 & 4.88)) long and folded in half and soldered to an "N" connector might be a help. I'm thinking of trying to make an 15" omni by taking a 29.04" (6 wavelengths) length of 12 gauge wire and folding it in half. Am I thinking reasonably?

10-01-2001

A long wire (multiple of wavelength) will not work well. You need a way of keeping the signal being recieved along its length in phase. See link below for an antenna design that can be adapted to 2.4 ghz operation.

http://www.repeater-builder.com/rbtip/wa6svt.html

Guerilla.net also has two designs for this type of antenna. The 6db (built from coax segments) works well. I have had no luck building the second (simpler) version which uses brass rod coils to keep signal in phase between the antenna elements.

6db antenna 2.4ghz
http://205.159.169.11/reference/antennas/2ghz_collinear_omni/

5db antenna (I could not get this one working too well)
http://205.159.169.11/reference/antennas/2ghz_collinear_omni_lowpwr/

good luck

10-01-2001

Those things look like a lot of work....at least compared to the pringles can. You've got all those rods to cut and wires to bend precisely....it starts off with a warning that this could take days or weeks to build depeding on how dedicated you are to the task. That starts to make a $125 antenna look pretty good!

10-01-2001

I built 4 omni's similar to the ones in the plans I posted. Yes it does take a while to build them. Unless you have a lot of spare time AND you are flat broke, I would suggest you buy one instead. I built them out of curiosity, to see how good they performed. I would not do it again. MUCH easier to buy one instead. I ended up with 2 decent performing omni's, 2 very poor performing ones, and a box full of extra brass rod and tubes. Stick to building tin can antennas, quad w/ reflector antennas, and pringles can antennas. They are reasonably easy to build.

10-01-2001

Here is a link to Antenna Systems. They have decent prices on various antennas and patch cables. (8db omni $79.00) Their prices are not as inflated as most other dealers.

http://www.antennasystems.com/broadband.html#anchor37473

10-04-2001

I built the omni in an evening. If you have any kind of modeling skills and a decent work space, it's not all that tedious.
Then again, I haven't jacked it into anything yet. Might be crap.

10-11-2001

I'm making the Pringle Antenna and I can't find the exact 1/4" in ID Al Tube. The best I can find is 1/2" OD Al tube that has an ID of about 3/8".

Is this going to be a problem? If it is the surface area (ID or OD??) that matters, I can calculate how much shorter I need to make the lengths.

Thanks in advance,

Tron Of Borg

10-11-2001

I believe it is correct to assume that the aluminum tubes are there only to maintain proper spacing between the elements. You could easily use two nuts (one on each side of the washer "element")to hold it at the proper spacing distance. You could also glue the washers to a 1/4 inch wooden dowel to form the collector. the rod material and construction technique is not important, so long as the elements are arranged correctly. We used to build yagis using aluminum tubes as the backbone, and also substituted wood and pvc with equal results. I would not increase the diameter too much on the tubes, they would begin to obstruct the surface of the washers (elements). Does anyone else have experience and advice with yagi construction?

If you want to build the simplest of directional antennas, see the link below: (2.4ghz coffee can feed)

http://www.qsl.net/wk8l/

they do work

10-14-2001

outcast-
those plans look pretty sweet, but the jpeg pictures they are in are poor quality, so you cant see the dimensions of the stuff on the plans or any detials, is there a clearer copy anywhere?
thanks

10-16-2001

They are a bit hard to read. The first page with the coffee can are a follows: diameter of can opening: 4.4 inches, length of can: 8.8 inches, distance of "n" connector from rear of can: 2 inches, diameter of wire soldered to "n" connector: 3/16 inch, length of wire soldered onto "n" connector: 1.12 inches (1/4 wave at 2.4ghz) I know the plans ont the other pages are even worse, I cannot make out most of them. I only intended to point out the basic coffee can antenna plans because they are very easy to build. For the "cigar" yagi, you could try using directors (elements) slightly smaller than a dipole at the given frequency. You would probably be safe with using washers with a diameter between 1 to 2 inch outside diameter. As for spacing, 1.2 inches between the washers will work fine. You also do not have to use 32 elements on the boom. This is a little overkill, half that many is a bit more practical. Once you get beyond about 10-12 elements, you see diminishing results.

10-16-2001

My company manufactures cellular/PCS/ISM-MMDS antennas; we sell primarily to the big wireless telcos, but if you want a REALLY good directional 2.4-2.5 GHz antenna check out our SI 5015-N @ http://www.swedcom.com/index1.html under products/ISM-MMDS. 13 dBd gain, H-plane -3 dBd down is a true 50 degrees, V-plane is 18, VSWR < 1.2... it's not cheap at around $500... but I can get average 8 Mbps from our office to our test facility about a mile away, and it's not quite LOS.

here ends the shameless plug.

Chris

10-27-2001

I can now vouch for the mini-Yagi in a Pringles can antenna. I built one in about an hour and it cost under $15. The N connector was $8, the rest was the metal rod, copper tubing and washers. I couldn't find threaded rod that wasn't bent and crooked at the local hardware stor and so bought 3/32" weld rod and threaded the ends - pretty easy if you have a tap and die set, but stick with the threaded stuff if that's your only option. I am still unsure if the previous statement about the spacers being metallic or possibly non-metallic, but to be sure, I used 1/8" copper soft tubing for a spacer. Washers were 1" with 3/32" holes I believe - these are the most difficult part to find, as big fender washers with little holes to match the rod you select are not as common as you'd think.

The greatest part in all this experimenting is the built-in test equipment by way of the integral Client MAnager, which tells you gain, noise, etc.-instant feedback is cool.

Next I think I will make a much longer yagi with more wavelengths than the (4) quarter wavelengths in the little Pringles can, for a permanent installation.

Thanks for all the help folks, this is a good forum!

10-01-2001	#1 (permalink)
Posts: n/a	Pringles antenna - allowable deviations? I'm trying to build a pringles-can directional antenna and am wondering how much I can deviate from the design (http://www.oreillynet.com/lpt/wlg/448). In particular, I'm having a hard time finding 1" washers with a 1/8" hole in the center. Does the size matter? I have some 3/4" washers with a 1/8" hole.....will they work? I'm also wondering what it would take to make an omni-directional antenna - does the pringles can 'focus' the reception or is the design of the element the focusing factor. If it's the former, could I use PVC pipe instead of a pringles can and have the antenna be more omnidirectional? On the 'original' pringles-can site (http://www.netscum.com/~clapp/wireless.html) there is mention of a di-pole antenna. It looks like a piece of wire a multiple of 1 wavelength (1 wavelength=4.84" (middle of 4.80 & 4.88)) long and folded in half and soldered to an "N" connector might be a help. I'm thinking of trying to make an 15" omni by taking a 29.04" (6 wavelengths) length of 12 gauge wire and folding it in half. Am I thinking reasonably?

10-01-2001	#2 (permalink)
Posts: n/a	omni antenna A long wire (multiple of wavelength) will not work well. You need a way of keeping the signal being recieved along its length in phase. See link below for an antenna design that can be adapted to 2.4 ghz operation. http://www.repeater-builder.com/rbtip/wa6svt.html Guerilla.net also has two designs for this type of antenna. The 6db (built from coax segments) works well. I have had no luck building the second (simpler) version which uses brass rod coils to keep signal in phase between the antenna elements. 6db antenna 2.4ghz http://205.159.169.11/reference/antennas/2ghz_collinear_omni/ 5db antenna (I could not get this one working too well) http://205.159.169.11/reference/antennas/2ghz_collinear_omni_lowpwr/ good luck

10-01-2001	#4 (permalink)
Posts: n/a	Antennas I built 4 omni's similar to the ones in the plans I posted. Yes it does take a while to build them. Unless you have a lot of spare time AND you are flat broke, I would suggest you buy one instead. I built them out of curiosity, to see how good they performed. I would not do it again. MUCH easier to buy one instead. I ended up with 2 decent performing omni's, 2 very poor performing ones, and a box full of extra brass rod and tubes. Stick to building tin can antennas, quad w/ reflector antennas, and pringles can antennas. They are reasonably easy to build.

10-01-2001	#5 (permalink)
Posts: n/a	antenna sales Here is a link to Antenna Systems. They have decent prices on various antennas and patch cables. (8db omni $79.00) Their prices are not as inflated as most other dealers. http://www.antennasystems.com/broadband.html#anchor37473

10-04-2001	#6 (permalink)
Posts: n/a	Home made I built the omni in an evening. If you have any kind of modeling skills and a decent work space, it's not all that tedious. Then again, I haven't jacked it into anything yet. Might be crap.

10-01-2001	#3 (permalink)
Posts: n/a	Those things look like a lot of work....at least compared to the pringles can. You've got all those rods to cut and wires to bend precisely....it starts off with a warning that this could take days or weeks to build depeding on how dedicated you are to the task. That starts to make a $125 antenna look pretty good!

10-11-2001	#7 (permalink)
Posts: n/a	What is more important? I'm making the Pringle Antenna and I can't find the exact 1/4" in ID Al Tube. The best I can find is 1/2" OD Al tube that has an ID of about 3/8". Is this going to be a problem? If it is the surface area (ID or OD??) that matters, I can calculate how much shorter I need to make the lengths. Thanks in advance, Tron Of Borg

10-11-2001	#8 (permalink)
Posts: n/a	element spacing I believe it is correct to assume that the aluminum tubes are there only to maintain proper spacing between the elements. You could easily use two nuts (one on each side of the washer "element")to hold it at the proper spacing distance. You could also glue the washers to a 1/4 inch wooden dowel to form the collector. the rod material and construction technique is not important, so long as the elements are arranged correctly. We used to build yagis using aluminum tubes as the backbone, and also substituted wood and pvc with equal results. I would not increase the diameter too much on the tubes, they would begin to obstruct the surface of the washers (elements). Does anyone else have experience and advice with yagi construction? If you want to build the simplest of directional antennas, see the link below: (2.4ghz coffee can feed) http://www.qsl.net/wk8l/ they do work

10-14-2001	#9 (permalink)
Posts: n/a	outcast- those plans look pretty sweet, but the jpeg pictures they are in are poor quality, so you cant see the dimensions of the stuff on the plans or any detials, is there a clearer copy anywhere? thanks

10-16-2001	#10 (permalink)
Posts: n/a	coffe can antenna They are a bit hard to read. The first page with the coffee can are a follows: diameter of can opening: 4.4 inches, length of can: 8.8 inches, distance of "n" connector from rear of can: 2 inches, diameter of wire soldered to "n" connector: 3/16 inch, length of wire soldered onto "n" connector: 1.12 inches (1/4 wave at 2.4ghz) I know the plans ont the other pages are even worse, I cannot make out most of them. I only intended to point out the basic coffee can antenna plans because they are very easy to build. For the "cigar" yagi, you could try using directors (elements) slightly smaller than a dipole at the given frequency. You would probably be safe with using washers with a diameter between 1 to 2 inch outside diameter. As for spacing, 1.2 inches between the washers will work fine. You also do not have to use 32 elements on the boom. This is a little overkill, half that many is a bit more practical. Once you get beyond about 10-12 elements, you see diminishing results.

10-16-2001	#11 (permalink)
Posts: n/a	My company manufactures cellular/PCS/ISM-MMDS antennas; we sell primarily to the big wireless telcos, but if you want a REALLY good directional 2.4-2.5 GHz antenna check out our SI 5015-N @ http://www.swedcom.com/index1.html under products/ISM-MMDS. 13 dBd gain, H-plane -3 dBd down is a true 50 degrees, V-plane is 18, VSWR < 1.2... it's not cheap at around $500... but I can get average 8 Mbps from our office to our test facility about a mile away, and it's not quite LOS. here ends the shameless plug. Chris

10-27-2001	#12 (permalink)
Posts: n/a	Pringles Can I can now vouch for the mini-Yagi in a Pringles can antenna. I built one in about an hour and it cost under $15. The N connector was $8, the rest was the metal rod, copper tubing and washers. I couldn't find threaded rod that wasn't bent and crooked at the local hardware stor and so bought 3/32" weld rod and threaded the ends - pretty easy if you have a tap and die set, but stick with the threaded stuff if that's your only option. I am still unsure if the previous statement about the spacers being metallic or possibly non-metallic, but to be sure, I used 1/8" copper soft tubing for a spacer. Washers were 1" with 3/32" holes I believe - these are the most difficult part to find, as big fender washers with little holes to match the rod you select are not as common as you'd think. The greatest part in all this experimenting is the built-in test equipment by way of the integral Client MAnager, which tells you gain, noise, etc.-instant feedback is cool. Next I think I will make a much longer yagi with more wavelengths than the (4) quarter wavelengths in the little Pringles can, for a permanent installation. Thanks for all the help folks, this is a good forum!

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode