Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software?
One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north?
Randy - N2CUA
Azimuth is referenced to True North.
Some software might allow magnetic, but that would likely be an optional alternative to true north.
73, Ken N2WWD
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: Saturday, January 09, 2010 9:26 AM To: [email protected] Subject: [amsat-bb] Azimuth question
Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software?
One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north?
Randy - N2CUA
_______________________________________________ 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
I sight on the North Star for all of my antenna projects. Easy to do and gets you right on (in the northern hemisphere, of course)
Pete WA6WOA
--- On Sat, 1/9/10, Ken Ernandes [email protected] wrote:
From: Ken Ernandes [email protected] Subject: [amsat-bb] Re: Azimuth question To: [email protected], [email protected] Date: Saturday, January 9, 2010, 7:02 AM
Azimuth is referenced to True North.
Some software might allow magnetic, but that would likely be an optional alternative to true north.
73, Ken N2WWD
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: Saturday, January 09, 2010 9:26 AM To: [email protected] Subject: [amsat-bb] Azimuth question
Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software?
One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north?
Randy - N2CUA
_______________________________________________ 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
Thanks everyone for the help .. I'm all sighted in on the North Star .. Actually, I went to wikipedia and read up on magnetic declination. It says that if you are east of the 0 degree line ( which I am in New York ) Then true north is east of magnetic north by that number of degrees as Shown on the declination map .. I'll listen to VO-52 and see how that goes.
Randy - N2CUA
-----Original Message----- From: Pete Rowe [mailto:[email protected]] Sent: Saturday, January 09, 2010 1:03 PM To: [email protected]; [email protected]; Ken Ernandes Subject: Re: [amsat-bb] Re: Azimuth question
I sight on the North Star for all of my antenna projects. Easy to do and gets you right on (in the northern hemisphere, of course)
Pete WA6WOA
--- On Sat, 1/9/10, Ken Ernandes [email protected] wrote:
From: Ken Ernandes [email protected] Subject: [amsat-bb] Re: Azimuth question To: [email protected], [email protected] Date: Saturday, January 9, 2010, 7:02 AM Azimuth is referenced to True North. Some software might allow magnetic, but that would likely be an optional alternative to true north. 73, Ken N2WWD -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: Saturday, January 09, 2010 9:26 AM To: [email protected] Subject: [amsat-bb] Azimuth question Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software? One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north? Randy - N2CUA _______________________________________________ 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
Randy,
I got interested by this, and looked up my QTH. When I moved here 25 years ago, the deviation was less than 30 minutes. It is now up to about 3 degrees. Good thing I have my references sighted in.
73s,
Alan WA4SCA
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: 09 January, 2010 18:10 To: 'Pete Rowe'; [email protected]; 'Ken Ernandes' Subject: [amsat-bb] Re: Azimuth question
Thanks everyone for the help .. I'm all sighted in on the North Star .. Actually, I went to wikipedia and read up on magnetic declination. It says that if you are east of the 0 degree line ( which I am in New York ) Then true north is east of magnetic north by that number of degrees as Shown on the declination map .. I'll listen to VO-52 and see how that goes.
Randy - N2CUA
-----Original Message----- From: Pete Rowe [mailto:[email protected]] Sent: Saturday, January 09, 2010 1:03 PM To: [email protected]; [email protected]; Ken Ernandes Subject: Re: [amsat-bb] Re: Azimuth question
I sight on the North Star for all of my antenna projects. Easy to do and gets you right on (in the northern hemisphere, of course)
Pete WA6WOA
--- On Sat, 1/9/10, Ken Ernandes [email protected] wrote:
From: Ken Ernandes [email protected] Subject: [amsat-bb] Re: Azimuth question To: [email protected], [email protected] Date: Saturday, January 9, 2010, 7:02 AM Azimuth is referenced to True North. Some software might allow magnetic, but that would likely be an optional alternative to true north. 73, Ken N2WWD -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: Saturday, January 09, 2010 9:26 AM To: [email protected] Subject: [amsat-bb] Azimuth question Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software? One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north? Randy - N2CUA _______________________________________________ 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
deviation >> declination. Duh.
Alan
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Alan P. Biddle Sent: 09 January, 2010 18:22 To: [email protected] Subject: [amsat-bb] Re: Azimuth question
Randy,
I got interested by this, and looked up my QTH. When I moved here 25 years ago, the deviation was less than 30 minutes. It is now up to about 3 degrees. Good thing I have my references sighted in.
73s,
Alan WA4SCA
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: 09 January, 2010 18:10 To: 'Pete Rowe'; [email protected]; 'Ken Ernandes' Subject: [amsat-bb] Re: Azimuth question
Thanks everyone for the help .. I'm all sighted in on the North Star .. Actually, I went to wikipedia and read up on magnetic declination. It says that if you are east of the 0 degree line ( which I am in New York ) Then true north is east of magnetic north by that number of degrees as Shown on the declination map .. I'll listen to VO-52 and see how that goes.
Randy - N2CUA
-----Original Message----- From: Pete Rowe [mailto:[email protected]] Sent: Saturday, January 09, 2010 1:03 PM To: [email protected]; [email protected]; Ken Ernandes Subject: Re: [amsat-bb] Re: Azimuth question
I sight on the North Star for all of my antenna projects. Easy to do and gets you right on (in the northern hemisphere, of course)
Pete WA6WOA
--- On Sat, 1/9/10, Ken Ernandes [email protected] wrote:
From: Ken Ernandes [email protected] Subject: [amsat-bb] Re: Azimuth question To: [email protected], [email protected] Date: Saturday, January 9, 2010, 7:02 AM Azimuth is referenced to True North. Some software might allow magnetic, but that would likely be an optional alternative to true north. 73, Ken N2WWD -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: Saturday, January 09, 2010 9:26 AM To: [email protected] Subject: [amsat-bb] Azimuth question Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software? One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north? Randy - N2CUA _______________________________________________ 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
_______________________________________________ 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
FYI...
The compass in the iphone will show you the difference between true and magnetic north for your current location.
regards
Tim
On 9 Jan 2010 at 19:09, Randy wrote:
Date sent: Sat, 09 Jan 2010 19:09:35 -0500 From: Randy [email protected] Subject: [amsat-bb] Re: Azimuth question To: 'Pete Rowe' [email protected], [email protected], 'Ken Ernandes' [email protected] Send reply to: [email protected]
Thanks everyone for the help .. I'm all sighted in on the North Star .. Actually, I went to wikipedia and read up on magnetic declination. It says that if you are east of the 0 degree line ( which I am in New York ) Then true north is east of magnetic north by that number of degrees as Shown on the declination map .. I'll listen to VO-52 and see how that goes.
Randy - N2CUA
Hi Randy
The north pointing was also an issue here. I try the north start, the sun shadow on my tower at noon, GPS, magnetic compass corrected for the true north but i was still off.
When my rotor control box lost his north setting i decided from an approximate north pointing to fine tune it while pointing on a satellite. I try first with AO-51. It take's me a couple of pass to be able to set my north alignment using this method. You will have to move you antenna back and forth writing the calculated azimuth and your maximum signal direction. When you get an whole list you just have to make the average of the differences and you just have to correct your north pointing with this difference. I was at an 19 degrees error and when i reset my control box to the north taking in account this corrected factor all the other satellite pointing became right on the spot.
The dramatic effect come at AOS and LOS when prior to this adjustment i was nearly unable to work anything below 5 degrees of elevation but after i often hear my downlink near 1 degrees and sometimes at half a degree.
It was easy here to readjust my north setting as my Alpha Spid rotor can be adjusted to the north without having to mechanically move the mast on the rotor probably not the best season to make this king of setting actually here.
I wrote "here" as i'm happy that some in Florida can actually feel what we can feel here when playing with the antennas and rotor outside in winter... Even in Europe they also have this great opportunity to make this new exciting experiment...
P.S. To our Canadian snow birds there is no need to go to Florida to get sub freezing point temperature you just have them just out of your home door here...but let say you will answer me back that you prefer minus 4C instead of my actual minus 20C... "-"
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe DSTAR urcall VE2DWE WAC BASIC CW PHONE SATELLITE
Randy, True North is used as a reference. Magnetic North changes with observer location and time. A user of Magnetic North is expected to make the correction to True North. Some satellite prediction programs give position of Sun and Moon to calibrate your antennas by knowing your Position and Time
Art, KC6UQH
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Randy Sent: Saturday, January 09, 2010 6:26 AM To: [email protected] Subject: [amsat-bb] Azimuth question
Is azimuth base on true or magnetic north When lining up the antenna system for satellites? When I looked it up, says true north. Is that true for ALL satrellite tracking software?
One website says 12 degrees 58 seconds West is the magnetic declination. So does that mean turn my antenna west by that amount from Magnetic north?
Randy - N2CUA
_______________________________________________ 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
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At 11:37 AM 1/9/2010, you wrote:
Randy, True North is used as a reference. Magnetic North changes with observer location and time.
Art, what does mag north have to do with time??
73, Dave, WB6LLO [email protected]
Disagree: I learn....
Pulling for P3E...
On Jan 9, 2010, at 1:47 PM, Dave Guimont wrote:
At 11:37 AM 1/9/2010, you wrote:
Randy, True North is used as a reference. Magnetic North changes with observer location and time.
Art, what does mag north have to do with time??
Magnetic deviation changes slowly over time as the earth's magnetic field changes. The rate and current deviation are usually pretty precisely known for most areas.
"No nation was ever so virtuous as each believes itself, and none was ever so wicked as each believes the other." -- Bertrand Russell
BTW, even Polaris isn't a perfect indicator of true north. It's up to 2 degrees off for latitudes from the equator to 60 degrees north, and you can read the nearby constellations to see when it's right on. Consult Bowditch if you really care.
73,doug
From: Bruce Bostwick [email protected] Date: Sat, 9 Jan 2010 13:52:01 -0600
On Jan 9, 2010, at 1:47 PM, Dave Guimont wrote:
At 11:37 AM 1/9/2010, you wrote:
Randy, True North is used as a reference. Magnetic North changes with observer location and time.
Art, what does mag north have to do with time??
Magnetic deviation changes slowly over time as the earth's magnetic field changes. The rate and current deviation are usually pretty precisely known for most areas.
"No nation was ever so virtuous as each believes itself, and none was ever so wicked as each believes the other." -- Bertrand Russell
_______________________________________________ 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
Magnetic north is not fixed and, over a timescale of several years, drifts around by several hundred miles.
On 09-Jan-10 19:47, Dave Guimont wrote:
At 11:37 AM 1/9/2010, you wrote:
Randy, True North is used as a reference. Magnetic North changes with observer location and time.
Art, what does mag north have to do with time??
Magnetic north is not fixed and, over a timescale of several years, drifts around by several hundred miles.
Anyone wishing to use a magnetic compass to orient can use the following:
TrueVariationMagneticDeviationCompass add west, going the other way, add east.
Two Virgins Make Dead Company add west....
73, Dave, WB6LLO [email protected]
Disagree: I learn....
Pulling for P3E...
Dave, A fraction of a degree per year, and at least once in the history of the Earth the North and South magnetic poles reversed.
Art
-----Original Message----- From: Dave Guimont [mailto:[email protected]] Sent: Saturday, January 09, 2010 11:47 AM To: [email protected] Cc: [email protected] Subject: Re: [amsat-bb] Re: Azimuth question
At 11:37 AM 1/9/2010, you wrote:
Randy, True North is used as a reference. Magnetic North changes with observer location and time.
Art, what does mag north have to do with time??
73, Dave, WB6LLO [email protected]
Disagree: I learn....
Pulling for P3E...
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The message was checked by ESET NOD32 Antivirus.
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The message was checked by ESET NOD32 Antivirus.
Dave, A fraction of a degree per year, and at least once in the history of the Earth the North and South magnetic poles reversed.
Art
Yes, I'm aware of that, it also rotates about 1° about true north, the earth wobbles a bit to change the AZ, but how many ham antennas in the world need that accuracy?
And I doubt that the average ham can orient within more than 2° by eyeball!
73, Dave, WB6LLO [email protected]
Disagree: I learn....
Pulling for P3E...
At 04:11 PM 1/9/2010, Dave Guimont wrote:
Dave, A fraction of a degree per year, and at least once in the history of the Earth the North and South magnetic poles reversed.
Art
Yes, I'm aware of that, it also rotates about 1° about true north, the earth wobbles a bit to change the AZ, but how many ham antennas in the world need that accuracy?
And I doubt that the average ham can orient within more than 2° by eyeball!
73, Dave, WB6LLO [email protected] Disagree: I learn.... Pulling for P3E...
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
For 144 & 432 that is probably adequate. On 2400 the beamwidth of my 33-inch dish is 10.6 deg. (24.9 dBi) so keeping a signal within 1dB, probably requires 3 deg beamwidth and knowing true north with an accuracy of 10% of that results in 0.3 deg accuracy.
Of course if you are doing something like eme on 1296 with a 16-foot dish the beamwidth is 3.38 deg. (34.9 dBi). For eme it is desirable to track within 1db of maximum gain which may is something like 1-deg. and 10% accuracy is 0.1 deg. How would you set up a dish azimuth so that it is that accurate to true north? For eme it usually requires comparison with tracking sw for location of the Sun or Moon. At these freq. and dish sizes one can detect solar and lunar noise to peak onto, then adjust az and el calib. to match tracking sw az and el.
As it turns out my dish digital az-el readout has 0.1 deg. resolution so that is best I can read. On the Yaesu B5400, one is lucky to determine direction within 7.5 deg. for azimuth and 3.75 deg. for elevation. Manually tracking AO-40 with the B5400 was very touchy, as fine adjustment is near impossible. But I did refine my azimuth positioning using solar noise on 2400.
For 144 or 432 probably the most accurate method for calib of azimuth is using a repeater many miles away (knowing both its Lat-Lon and your Lat-Lon with bearing sw that produces a great-circle bearing).
73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com 500-KHz/CW, 144-MHz EME, 1296-MHz EME DUBUS Magazine USA Rep [email protected] ======================================
Dave, If you are technically correct or give a rough answer you get nit picked form on side or the other. Near by magnetic objects can cause serious errors using the Sun or Moon for alignment solves all problems for both azimuth and elevation. For near DC 70cm and longer wavelengths a pointing error of less than 10 degrees is insignificant. 13cm and shorter accuracy becomes more important. Art
-----Original Message----- From: Edward Cole [mailto:[email protected]] Sent: Saturday, January 09, 2010 7:02 PM To: Dave Guimont; [email protected] Cc: [email protected] Subject: Re: [amsat-bb] Re: Azimuth question
At 04:11 PM 1/9/2010, Dave Guimont wrote:
Dave, A fraction of a degree per year, and at least once in the history of the Earth the North and South magnetic poles reversed.
Art
Yes, I'm aware of that, it also rotates about 1° about true north, the earth wobbles a bit to change the AZ, but how many ham antennas in the world need that accuracy?
And I doubt that the average ham can orient within more than 2° by eyeball!
73, Dave, WB6LLO [email protected] Disagree: I learn.... Pulling for P3E...
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
For 144 & 432 that is probably adequate. On 2400 the beamwidth of my 33-inch dish is 10.6 deg. (24.9 dBi) so keeping a signal within 1dB, probably requires 3 deg beamwidth and knowing true north with an accuracy of 10% of that results in 0.3 deg accuracy.
Of course if you are doing something like eme on 1296 with a 16-foot dish the beamwidth is 3.38 deg. (34.9 dBi). For eme it is desirable to track within 1db of maximum gain which may is something like 1-deg. and 10% accuracy is 0.1 deg. How would you set up a dish azimuth so that it is that accurate to true north? For eme it usually requires comparison with tracking sw for location of the Sun or Moon. At these freq. and dish sizes one can detect solar and lunar noise to peak onto, then adjust az and el calib. to match tracking sw az and el.
As it turns out my dish digital az-el readout has 0.1 deg. resolution so that is best I can read. On the Yaesu B5400, one is lucky to determine direction within 7.5 deg. for azimuth and 3.75 deg. for elevation. Manually tracking AO-40 with the B5400 was very touchy, as fine adjustment is near impossible. But I did refine my azimuth positioning using solar noise on 2400.
For 144 or 432 probably the most accurate method for calib of azimuth is using a repeater many miles away (knowing both its Lat-Lon and your Lat-Lon with bearing sw that produces a great-circle bearing).
73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com 500-KHz/CW, 144-MHz EME, 1296-MHz EME DUBUS Magazine USA Rep [email protected] ======================================
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For 144 & 432 that is probably adequate. On 2400 the beamwidth of my 33-inch dish is 10.6 deg. (24.9 dBi) so keeping a signal within 1dB, probably requires 3 deg beamwidth and knowing true north with an accuracy of 10% of that results in 0.3 deg accuracy.
Of course if you are doing something like eme on 1296 with a 16-foot dish the beamwidth is 3.38 deg. (34.9 dBi). For eme it is desirable to track within 1db of maximum gain which may is something like 1-deg. and 10% accuracy is 0.1 deg. How would you set up a dish azimuth so that it is that accurate to true north? For eme it usually requires comparison with tracking sw for location of the Sun or Moon. At these freq. and dish sizes one can detect solar and lunar noise to peak onto, then adjust az and el calib. to match tracking sw az and el.
Yes, I used sun noise to align my 36" dish at 2.4 gigs, it was certainly adequate for ham work...
I've been tempted to try EME, and may yet do so.... Looks as tho any HEO is a way off, if ever...
But still counting on ESA and Peter to make it so...
73, Dave, WB6LLO [email protected]
Disagree: I learn....
Pulling for P3E...
participants (12)
-
Alan P. Biddle -
Art McBride -
Bruce Bostwick -
Dave Guimont -
Doug Faunt N6TQS +1-510-655-8604 -
Edward Cole -
Ken Ernandes -
Luc Leblanc -
Nigel Gunn G8IFF/W8IFF -
Pete Rowe -
Randy -
Tim Tuck