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Re: AO-27 and MIR on an HT?



    A027 is tough to receive.  I have a gain antenna on my car and can just
    barely receive a noisy signal for only a small part of the pass.
    I use an Arrow dual band beam when I want to really try to work AO27.   I
    run 2 watts into the 2m uplink on the 2m side of the Arrow.  This is more
    than enough during the week when the number of users is lower.

Right, a gain omni will only be useful on low elevation passes.  Using a 2M
quarter-wave tuned for decent SWR at 437 MHz will work much better for most
passes.  Yes, a 2 meter quarterwave; it won't work very well at 70cm for
terrestrial use, the pattern in the vertical plane sends most of the energy
skyward.  But because of reciprocality, that's exactly what you want for
AO-27.  For a 2 meter quarterwave ground plane in open space, see:

	http://www.qsl.net/kd6pag/nec/2mModGndP.html

So, with a sensitive receiver away from urban QRM, you may be able to 
homebrew such an antenna using a RS rain gutter mount and do alot better
than a rubber duck.

Just make sure you can at least copy partial callsigns before transmitting
and don't expect necessarily to be heard on weekends.  And you probably
won't hear the bird well enough while your vehicle is in motion, even if
the road noise doesn't overwhelm the audio.

			-- KD6PAG


P.S.  SF Bay Area folk, neither this nor a long rubber duck will work if
you're even vaguely line-of-sight to San Rafael, unless you can null out 
the spur at 437.750 Mhz (and also aren't too close to any of the numerous
ridgeline pager sites).
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