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RED = Horizontal Plane
BLUE = Vertical Plane
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So cool. I’ll need to get that software. The antenna is doing surprisingly well with a SWR of 5. Actual length is 10” but if you get a chance, can you run it out to about 19” since you’ve already got it modeled. I’m bouncing around the idea of another duct and the overlap will probably be about an inch.
Thant’s mandatory today for health reasons. Even the drink cans should be coated inside, where food/liquid comes in contact with Aluminum. A Canadian study discovered that Al is bad for brain: Safety evaluation of dietary aluminum - PubMed
“A study from Canada reports cognitive and other neurological deficits among groups of workers occupationally exposed to dust containing high levels of aluminum. While the precise pathogenic role of aluminum in Alzheimer’s disease (AD) remains to be defined…”
That’s the purpose of a horn.
It matches the waveguide impedance to that of free space, which is approximately 377 Ohms.
On his page, Lincomatic says:
The conical collector is 7.25" in diameter on the big side, w/ a 30degree flare. This was just a quick prototype so I made the collector out of 2 coat-hanger circles, separated w/ four 4" long coat hanger supports covered in aluminum foil. the final design will need to be more durable to stand up against wind & hail.
The 30° angle is the point to be aware of.
Apparently looks as if the Pringles can’s Aluminum foil has a transparent plastic film coating over it to prevent direct contact of food with Aluminum.
The Aluminum foil is actually a wide ribbon, attached to cardboard in the shape of a helix, with overlap joint very visible (see photo 2 below). If my guess about plastic coating over Aluminum is right, then although the can will show continuity from end to end, the flow of current will NOT be parallel to axis of Cylinder. Instead it will follow a helical path.
Photo 1:
Outside of “Pin-fed Circular Waveguide Antenna” made of Pringles Can
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Photo 2:
Inside of “Pin-fed Circular Waveguide Antenna” made of Pringles Can
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SOURCE OF PHOTOS:
_http://www.antennamagus.com/blog/564/building-a-cantenna-from-a-pringles-can_
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RED: Horizontal Plane
BLUE: Vertical Plane
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This may or may not be true, but can be of academic interest only anyway.
The pringles cantenna is nearly twenty years old. It was never claimed to be “great”, however it was demonstrated to work. More importantly, the dimensions of a pringles cantenna make it completely unsuitable for 1090MHz, so a discussion of its theoretical failings seem to offer little value on this site.
The pringles cantenna is best thought of as a Proof of Concept and there have been dozens of “better” designs published since.
GDR’s seems to work, but also shows the same “theoretical” flaws you describe.
I have uploaded 4NEC2 model files to Dropbox.
If anyone is interested to run the simulations himself, he can use these files.
CLICK TO DOWNLOAD
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NOTE:
To run these model files, you have to first download and install the 4NEC2 software from here (free of cost)
That’s so crazy:
“Nec2dXS Fortran source-code and compiling instructions to create your own Nec2d executable files.”
I didn’t hear of Fortran since my (distant) college years.
Fortran, I got my first HD in Uni in Fortran. I think my mum worked with it in the 60s and 70s.
Who knew they still made comipilers
http://www.fortran.com/ 
Knowing what Fortran is dates us. Probably we are the few that saw active or used “card readers” that really read cards. Punch cards.
Ah, and… you British people … “Uni”. Always “Uni”, never “University”. We did it too in my language - shorten the name, to act like is something casual, nothing big, but really just to show off in front of others.
Facultatea became Faculta… Politehnica became Poli…
In US they don’t do this. College is always called College.
PS: In US that’s an University 4 yr level, not the College from EU (lower level)
I know. Born in U.S. raised in a British Country. Living again in the U.S.
Did punch cards and tape. Even used 16" HDD platters as frisbees (we found them in the rubbish).
Did some work, when in High School, at a Uni that had a 16 bit micro with TTY, Paper tape and 8" floppies. A Professor that used it left and no one knew how to use it. I think it ran CPM.
I have built one that ran CP/M 86 (Z80 processor).Let’s not destroy more this thread or a mod will slap us 
We do, but with the name vice the generic term Uni.
e.g. California Polytechnical Institue is commonly referred to as Cal Poly.
I loved Fortran. It was the first programming class I took in college, CS101. Prior to that I had only learned basic in high school. Later, when I started using C, all of my code was still structured like I was programming in Fortran until I got the hang of C and recognized how powerful it was.
Brings back memories of discrete components and vacuum tubes like the Nuvistor,
miniaturized for use in avionics. The radar shop I worked in had a punched paper tape reader to
load diagnostic routines for the Doppler radar. Almost all the digital displays on the test equipment were
Nixietubes. LEDs were just starting to make inroads in test gear at the time.
Notice the “5” digits in the lower picture. They’re inverted 2s.
As near as I know, the Russians were the only ones that manufatured Nixies like that.
They’re still my favorite display!
Blue LED were green ones cooled in liquid nitrogen and they promised that “one day” they will work in free air.
That was in 1974. No green LEDs. Only red ones.
