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Secret service

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"Even the Secret Service has taken an interest in the cantenna." Can we get a source for this?

splintax (talk) 12:51, 6 October 2005 (UTC) [reply]

Can we get a photo?

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Please? Prometheus-X303- 23:37, 8 October 2006 (UTC)[reply]

more photos here https://www.flickr.com/search/?license=4%2C5%2C9%2C10&text=cantenna&advanced=1 Victor Grigas (talk) 02:55, 8 January 2017 (UTC)[reply]

Spider Omni

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And what does "more potent" mean with regard to antennas? Certainly not dB gain. A cantenna can have up to 24 dB gain, while an omnidirectional unipole is what 3 or 4? Remove that nonsense. Spike2021 (talk) 03:45, 8 May 2008 (UTC)[reply]

Legality

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I know that I am an unregistered user, so fogive me, but should there be a section on the 'Legality of Cantennae' somewhere in the article?

I remember reading about how the FCC doesn't like the amplification of signals that people are doing at home. 130.20.74.174 23:57, 20 September 2006 (UTC)[reply]

Amplification via antenna-only, to some extent, is still legal under FCC part 15 as long as certain limits are not reached. 147.145.40.44 22:52, 25 January 2007 (UTC)[reply]

The FCC doesn't exactly like homebrew antennas IIRC, not specifically the amplification. T3h 10:12, 24 March 2007 (UTC)[reply]

  • Then their are a lot of "roll their own" hams that are in trouble. You mind showing me the applicable FCC part? I've been building antennae since I was 8, and I've only had to talk to FCC enforcement 1 time in all these years (and it turns out I was very legal under part 15, which typical cantenna equipment falls under) 66.28.178.68 21:57, 11 September 2007 (UTC)[reply]


"They're unsophisticated but reliable, and it's illegal to possess them," said Lozito of the Hi-Tech Crimes Task Force.

http://www.boingboing.net/2005/07/26/hitech-cop-cantennas.html

http://seclists.org/isn/2005/Jul/0098.htmlOmegatron 07:29, 3 September 2007 (UTC)[reply]

other

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A comparison to http://en.wikipedia.org/wiki/Parabolic_reflector would be nice. —Preceding unsigned comment added by 68.229.179.194 (talk) 16:01, August 30, 2007 (UTC)

There are some off-wiki pages that try to summarize the performance differences of lots of different antennas: [1] [2] Is that what you were suggesting? I'm not sure what a parabolic antenna has in common with a cantenna other than that they're two designs that work well for wifi frequencies. --Underpants 16:45, 1 March 2009 (UTC)[reply]

Waveguide vs. yagi

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Perhaps the article could make a clearer distinction between the two most popular types of antennas that the term "cantenna" is applied to? The article does note that waveguides are the most common, and that yagis/omnis/sector/etc antennas are possible. But it seems like the "Pringles cantenna" is the second-most popular, and is almost always a yagi (with washers put at specific intervals down a threaded bolt that runs down the center of the cantenna).

If this is an accurate description, it might be good to include it. I mention this because when I first started learning about cantennas, most of the popular-press mentions I'd heard of referred to the Pringles cantenna, and Pringles cantennas aren't really the right dimensions to make a waveguide antenna, and for a while I (mistakenly) thought that Pringles cantennas were the most common version. --Underpants 16:45, 1 March 2009 (UTC)[reply]

Split

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71.167.66.118, please justify the need for a split, or your assertion "Origin of the name: that's not the same thing". A lack of discussion will result in the removal of the {{split}} template.

I see no need for an article on the Heath 'Cantenna. It's just a dummy load; how much is there to say about it? --Jc3s5h (talk) 18:23, 11 October 2009 (UTC)[reply]

Heath's "Cantenna" existed in about 1970; don't recall how far back before that it went. Yes, it's a dummy load, but it is designed to be 'flat' over an extremely wide range of frequencies. I never owned one; but in 1980 I built what you are NOW calling a "Cantenna" to receive 2.45 GHz signals. At that time, it wasn't called a "Cantenna". Allassa37 (talk) 04:22, 18 January 2021 (UTC)[reply]

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"Cantenna calculator" must be changed to "Cantenna calculator (2.4 GHz)" --lgoncalv 11 October 2009 —Preceding undated comment added 03:19, 18 October 2009 (UTC).[reply]

Needs some sort of design equations.

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I've been thinkign about building one of these, and how to do it optimally is far from best. For example, if the can is too small in diameter, it would act as a "waveguide beyond cutoff" and signals would propogate down in with very high loss. If the diameter is too large, various modes would be set up, and that likely to cause problems. Should the diamater be such that the antenna works in the fundamental mode of the waveguide?

How far from the feed be from the back or front? How long should the feed be?

Whilst not knowing the answers to these questions, as a profeesional (chartered) engineer, who specialises in RF, I think these are important questions. I think to make one properly, take a lot more than taking a random size bean can and poking a wire in at some random location and some random length.

Other important questions would be about the gain. The article states " The typical gain for this kind of antenna in the 2.4 GHz Wi-Fi band is about 10 dB.", but without a reference (usually dBi or dBd), that is a useless statemant. It is a bit like a newpaper sstating the temperature is expected to be 10 degrees. Without clarifying if it is Centigrate or Farenheight, it is a useless statement.

It is in my opinion, a rather poor article, written by people who don't know the subject, but deceide they can contribute something. Drkirkby (talk) 10:23, 12 January 2014 (UTC)[reply]

Agreed. The Wikipedia article on antenna engineering is of high quality, quite unlike this one which offers no theory whatsoever, nor any insight into how it could work. What's needed at the very least is an explanation of how a planar EM wave from a distant source is coupled by a cantenna into a transmission line, along with calculations and/or measurements (ideally both) of directivity, efficiency. and (hence) gain, well as impedance at the point where the signal is handed off to the transmission line. As the article stands, someone basing their antenna design on it could inadvertently build one with efficiency and/or gain worse than that of a simple dipole antenna. Vaughan Pratt (talk) 23:40, 7 June 2015 (UTC)[reply]
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Pringles

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Quote: Although some designs are based on a Pringles potato chips can, this tube is too narrow to increase the 2.4 GHz signal by a useful amount, although at 5 GHz it would be about the right size.

D'oh, you can cut them open to increase their diameter. Maikel (talk) 00:12, 22 August 2018 (UTC) D'oh, then they are no longer tubular. Better to get a steel can of the right diameter. — Preceding unsigned comment added by 124.191.177.31 (talk) 03:28, 18 March 2019 (UTC)[reply]

Confused about gain

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Hi!

According to this article a cantenna can be used to increase range. But it doesn't even give a ballpark number how many dB vs an isotropic or a dipole antenna. Reading from the article I have no clue how those things perform. I know this is not the best article, and it has been criticised for some of the same omissions 10 years ago on this Talk page when those antennas were probably still more common. And since half the links broke without somebody repairing them. But I still would ask, if somebody finds a source on how big the gain and the directionality of those cantennas is and ideally a radiation pattern to add this information here. Kwinzman (talk) 17:17, 6 February 2023 (UTC)[reply]