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RE: Full Wave Loops



> Ok, so given my tight space restrictions, let me pose this question...
> 
> If I were to cut 2 Loops.  One 27.8 inches long on 432MHz and 
> mount that 6
> 1/2 inches above a sheet of metal (Which is 1/4 wavelength 
> theoretically
> creating a nice 2db donut shaped pattern across the horizon.) 
> and then do
> the same on 145 (83 inches in diameter and approx 19 1/4 
> inches up), would
> this be a good effective antenna array for AO-27 and UO-14?

Depends on what you want to achieve.  From my experience, I prefer
directional antennas.  I find the extra gain is very useful, provided you
can point the antenna at the bird.  And I use the most reliable rotator to
do this - the product of millions of years design and development (just pick
the thing up and point it! :-) ).

If you use two loops in your design, you're getting closer to the classic
eggbeater with a reflector.  The eggbeater is CP overhead and LP at low
elevations.  If you have to use a fixed antenna, go for something with
circular polarization.

Some stations with fixed antennas (or fixed polarization) have reported
significant QSB on UO-14, and I have observed such QSB on both UO-14 and
SO-35.  With the portable beam, the downlinks are rock steady.  I have a
.MP3 on my web site of a UO-14 pass where several stations complained of
severe QSB on the downlink, but you'll hear a rock steady signal (the
recording was  done off the beam).

> 
> I know I ask too many questions, but this is why I spent 10 years in
> college and my friends call me Doctor Dave.. :grin:

Hehehe. :-)
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