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AO40 uplink quadrifilar

I've done some wide range testing using a homebrew quadrifilar
as a 70 cm uplink.

Others may be interested, and here are some statistics:

The antenna is 5" in diameter, 7 1/2" long, if mounted separately a 17"
turn radius, and it weighs about 1 1/2 pounds.  The beamwidth is about 140°,
I mount mine at 30° EL and one AZ setting (mounted separately) will take care
of over 1/2 of a pass.

30 watts or less up the pipe is all the power I ever use for reasonable
pointing angles, but the antenna accepts up to my 100 watt amplifier if

Eventually I'll mount one on my portable AO40 dish set-up and use the same
AZ/EL as the dish.  I use a "quad pod" (designed for portable work), and
two of us can set up anywhere, and be on the air in 30 minutes from the time
we start to off-load the equipment...Amd all of the gear will fit in my
standard size sedan...

That should satisfy some of the naysayers about using AO40 as an adjunct to
ARES operations in the event of an emergency, but I'm too busy experimenting
to go down that road anymore!

I'll put up some pictures of the entire setup in a few days, but the
antenna is described in quadfil1.zip at:


Be glad to assist anyone with questions...

            73, Dave wb6llo@amsat.org
                    Disagree: I learn....
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