Wave guide antenna?

I was wondering if anyone has experimented with a really long version of
the cantenna. What about getting a 3 1/2" copper pipe and making say a
5 or 10 foot long wave guide. It wouldn't be very practical but it
would be interesting to see how well it worked.

--
Chris W

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

If you're really into it you might like to read
up on the results of the Wi-Fi "shootout" at
Vegas not long ago. Two Hams won out with 32 miles. Of course their antennas
were something to behold. Somewhat modified waveguides. Regards


"Chris W" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I was wondering if anyone has experimented with a really long version of
> the cantenna. What about getting a 3 1/2" copper pipe and making say a
> 5 or 10 foot long wave guide. It wouldn't be very practical but it
> would be interesting to see how well it worked.
>
> --
> Chris W
>
> "They that can give up essential liberty
> to obtain a little temporary safety
> deserve neither liberty nor safety."
> -- Benjamin Franklin, 1759 Historical Review of Pennsylvania
>
>

Chris W wrote:

> I was wondering if anyone has experimented with a really long version of
> the cantenna. What about getting a 3 1/2" copper pipe and making say a
> 5 or 10 foot long wave guide. It wouldn't be very practical but it
> would be interesting to see how well it worked.

If antenna theory returns to me properly, I don't think that you would see
any benefits from having a 10 foot waveguide feeding a waveguide antenna.
All that would happen would be the antenna would be ten feet from the signal
source at the end of a waveguide. It wouldn't be any more directional and
it wouldn't have any more gain.

Now if you take the pringle can and design a horn antenna for it, that could
show some benefits. A horn antenna looks like a funnel that connects to the
end of the waveguide so that it can collect signals coming from the desired
direction and assist in matching the characterisitic impedance of the
waveguide to free space. It also dose some directional beam shaping for the
transmit side of the signals as well.

If interested I would recommend looking at some texts on the subject. A
basic one that is avaiable is the Antenna Refernce book published by the
American Radio Relay League. The League also sells a book published by
their British counterpart, The Radio Society of Great Britain, on
microwaves. It would likely have some good information on waveguides,
waveguide antennas and horn antennas like the funnel shaped antennas are
called.

Allan Butler <(E-Mail Removed)> wrote:

> Now if you take the pringle can and design a horn antenna for it, that could
> show some benefits. A horn antenna looks like a funnel that connects to the
> end of the waveguide so that it can collect signals coming from the desired
> direction and assist in matching the characterisitic impedance of the
> waveguide to free space. It also dose some directional beam shaping for the
> transmit side of the signals as well.

< http://www.nodomainname.co.uk/Antennas/antenna.htm >
Can with conical horn