I was just going to say that Polaris is close to the north celestial pole but not quite exactly on it, and if you're absolutely insanely obsessed with accuracy, you probably want to take two shots on it 180 degrees apart (12 hours apart in winter, if your latitude is high enough that you can fit two observations 12 hours apart into one night, or the same time on two nights 6 months apart, or whatever), and split the difference. If you're aiming at satellites, an error of less than a degree isn't going to matter much, though .. your antenna's main lobe is almost certainly wider than that. :)
On Dec 28, 2007, at 10:49 AM, Michael R. Owen wrote:
All -
For what it's worth, Polaris' declination is 89.2 degrees. Consequently, it can be as much as 0.8 degrees "off" from true North.
For aligning an antenna whose beamwidth is 15-30 degrees, this error is trivial of course.
W9IP
Luc Leblanc wrote:
I don't know if the old Columbus trick works in the southern hemisphere but here i calibrate my antennas on Ursa Major AKA The north star.
Just place yourself just under your tower or your beam supporting structure locate the north star and pointed your antenna.
For those who are not able to see the north star too bad take a GPS i check with mine against the north star and its closed enough just make sure you are programming to see the thru north not the magnetic north.
"Is it true that water flush in reverse side in drain if you are in the southern hemisphere? an old non believer saying!
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
ENGLISH: A language that lurks in dark alleys, beats up other languages, and rifles through their pockets for spare vocabulary.