Hi all, I think we need some clarification. Which satellite(s)are we talking about, when receiving with the ARROWS antenna ? The ARROW antenna are linearly polarised.
What latitude is your QTH ? Regarding satellites - some have linear polarisation - some have circular polarisation. AO-51 has Right Hand Circular Polarisation on the "normal" repeater downlink (435.300 MHz), SO-50 has linear polarisation - the same applies to AO-27. The satellites attitude are stabilised with permanet magnets. This may give different results depending upon where you are. Here in Copenhagen it is a great advantage to "twist" the ARROWS antenna to improve the downlink signal from AO-27. We are close to the North Pole (hi) Everyone may be right :-) 73 OZ1MY Ib ----- Original Message ----- From: "Roger Kolakowski" <[email protected]> To: "Clint Bradford" <[email protected]>; <[email protected]> Sent: Sunday, August 16, 2009 11:34 PM Subject: [amsat-bb] Re: Arrow Antennas > I will say that I can improve my 437 reception by rotating the beam...I also > have gotten better signals by aiming the beam at a point on the ground 100 > feet away... > > Why criticize? Everyone else can do anything they want to their antennas > without me getting upset...afterall, it's not MY antenna. > > Now if someone wants to point me toward scientific theory, antenna modeling > programs, propagation theory...then I can stand up and listen...until then, > my best signal is most important to me. > > Roger > WA1KAT > > > Roger > WA1KAT > ----- Original Message ----- > From: "Clint Bradford" <[email protected]> > To: <[email protected]>; <[email protected]> > Sent: Sunday, August 16, 2009 4:19 PM > Subject: [amsat-bb] Re: Arrow Antennas > > > > > ... Why are we modifying the Arrow? > > > > > ... Because someone's analysis says the element length is all wrong ... > > > > So Al Lowe's software program which he used to design these is all wrong? > > > > Sorry to get defensive on Al's behalf. This thread just "feels" like a > re-hash of an "engineer's view vs. real world results" argument. Like when I > was told here - by engineers - that it mattered how I twisted my Arrow while > working the sats. "Ya gotta take polarization into account, Clint - there's > a 22db difference when you turn your antenna 90 degrees - a tremendous > performance hit if you don't take this into account ... " > > > > Yet in the real world of demonstrating workin' the birds, there's no such > performance degradation. I have hundreds of witnesses to this fact: Capture > SO-50 and AO-51 with the Arrow and operate TX and RX while twisting the > antenna in different angles doesn't change the great reception and > transmission quality. > > > > If you are in the market for an Arrow, I simply suggest that you use it as > offered to you. You will be pleased with its 2M and 440 amateur bands > performance. And leave the modding of the elements w-a-y on the bottom of > your "things to do" lists. > > > > Clint Bradford > > > > ---------------------------------- > > Clint Bradford, K6LCS > > http://www.clintbradford.com > > _______________________________________________ > > Sent via [email protected]. Opinions expressed are those of the author. > > Not an AMSAT-NA member? Join now to support the amateur satellite program! > > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > > > _______________________________________________ > Sent via [email protected]. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
