I'm putting together a cantenna like the one here:
Also, the writer says the can's dimensions are important. The one I want to use it 4" diameter x 6" length (the calculator says to put the N-connector 1.72 inches from the bottom). Are those good dimensions or should I look for another can? Thx.
sillyputty hath wroth:
No. It's not mechanically stable enough. It will move around, untwist, fall over, and cause problems. Use solid wire.
The position of the probe varies somewhat with the can dimensions. The URL you mentioned in includes a calculator. Use it. Looks like 6" is a bit short. Also see calculator at:
See list of suitable cans and calculator near bottom of:
More cantenna calculators:
The same calculator that says 1.72" for the probe also says 5.15 as the 3/4 length, which is explained in the text just below as the minimum desireable, so you should be okay at 6" in length. It would be better to be a full wavelength, listed in the chart as 6.87, but you have what you have. You could solder two of your cans together to get more length.
In the real world, my two-can cantenna seemed to be a little stronger, but too directional. It was tripod mounted by soldering a 1/4-20 nut to the outside, but it would drift off target.
Bob Alston used a single coffee can.
My user preferred a single larger coffee can. Not as strong, but more stable. The "3lb" can is 6" in diameter, which is too low in frequency range according to the calculator, but more acceptable in use.
Bob Alston's coffee can
Clarence Dold's two coffee can picture
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