[amsat-bb] True bearings vs. magnetic

[Mike Diehl]

Generally this question is asked WRT calibrating a rotor to north. In these cases the antennas on the rotors will be higher gain with a more narrow beam width. One must know all the variables like beam width and deviation at the QTH to say whether it is important or not. 

73,
Mike Diehl
W8LID


> On Jun 3, 2018, at 14:48, John KI4RO <johnki4ro at gmail.com> wrote:
> 
> That's my point...for the average guy using a standard ARROW it isn't that big a deal....just get it pointed N or S and away you go.  hi hi
> 
> 
> 73
> John KI4RO
> 
> 
>> On Sun, Jun 3, 2018 at 2:41 PM, Mike Diehl <diehl.mike.a at gmail.com> wrote:
>> You bring up an important point regarding beam width. The link provided shows a 3 element with 100° width so you need to be within 50° of either side of center to be inside the front lobe. 
>> 
>> Now consider a V/UHF beam that can have 3-5x as many elements. Say for instance you’re at 30° beam width or 15° to either side of center. If the station is off by 12.5° they are almost completely outside the lobe. 
>> 
>> With my 5x9 Arrow I notice just how much more accurate I need to be when pointing over the 3x7 Arrow II if I want maximum gain. 
>> 
>> That said, just how important it is to be true north versus magnetic north is going to depend on your beam width. 
>> 
>> 73,
>> Mike Diehl
>> W8LID
>> 
>> > On Jun 3, 2018, at 12:10, John KI4RO <johnki4ro at gmail.com> wrote:
>> > 
>> > I don't think its all that critical based on what I see here:
>> > 
>> > http://www.dx-antennas.com/Yagi3.htm
>> > 
>> > 
>> > 73
>> > John KI4RO
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