----- Original Message -----
From: "Vince Fiscus, KB7ADL" vlfiscus@mcn.net To: "i8cvs" domenico.i8cvs@tin.it Sent: Tuesday, September 06, 2011 11:02 PM Subject: Re: [amsat-bb] Re: Magnetic North vs True North
Hi domenico,
I've always used the north star (Polaris) to set my rotor to true North or "near" true North, and at 45.8 degrees N Lat it's easy to use the north star to double check rotor elevation too. It's not 100% accurate. To be 100% you might need some sort of astronomical almanac, but my antennas are really low gain so accuracy for me isn't a problem. But I like to be close, even so.
73 KB7ADL
Hi Vince, KB7ADL
I too have always used the Polaris and found this procedure very satisfactory for the accuracy and backlash of the gears in our amateur rotator for VHF and UHF antennas.
For the S band at 2400 MHz and a 1.2 meter dish to calibrate the Azimuth and Elevation I use the Sun Noise but the rotators have negligible backlash and the position readout can estimate +/- 0.25°
Best 73" de
i8CVS Domenico