Hello,
I use the automatic antenne deriction programm ARSWIN so I can beam fast and (not) correct enough because the I have 4*17elm long booms in phase.
will it be possibel to have the option for to use 6digits in the VHF locator check or a option to switch from 4 to 6 char. to have the ant direction.
many thanks . I feel that the difference you mention in the small areas is hardly worth bothering with, should not make any practical difference to QTF or QRB.
73's Luc on7kz
VHF Locator check
VHF Locator check
Hi Luc
For v2 I have acted on your suggestion thus....
When 4 figure locator is added to the locator check box the normal locator Search takes place, after which it is possible to add further two letters for the more accurate QTF.
73 Colin G0CUZ
Winlog32 Author
For v2 I have acted on your suggestion thus....
When 4 figure locator is added to the locator check box the normal locator Search takes place, after which it is possible to add further two letters for the more accurate QTF.
73 Colin G0CUZ
Winlog32 Author
VHF Locator check
Hi Colin.
quote:When 4 figure locator is added to the locator check box the normal locator Search takes place, after which it is possible to add further two letters for the more accurate QTF.
Just a quick thought, but most locator calculators return the exact grid co-ordinates given in the locator, thus returning the SW corner of the area covered. The problem is that even for a six character locator, this can be rather more than 7km from the actual QTH. To minimise the error, one needs to return the co-ordinates of the centre of that area rather than the SW corner.
As an example of this, take my mother's QTH. Her actual co-ordinates are 53º2'19 N, 0º4'53 E which corresponds to JO03AA. Taking the SW corner of that locator, we get 53º0'0 N, 0º0'0 E which is some 6.9 km away. However, taking the centre instead, we get 53º1'15 N, 0º2'30 E which is only 3.3 km away, less than half the distance.
The conversion between the two is simply the addition of a fixed offset to both the final latitude and longitude - 1'15 and 2'30 respectively when a six character locator is given, and 30' and 1º respectively when only a four character locator is given. As a result, there is no real time penalty for doing so as far as code execution time is concerned.
Best wishes from Riley G7GOD / KB8PPG
Edited by - rhw2 on 01/04/2003 05:23:20 AM
quote:When 4 figure locator is added to the locator check box the normal locator Search takes place, after which it is possible to add further two letters for the more accurate QTF.
Just a quick thought, but most locator calculators return the exact grid co-ordinates given in the locator, thus returning the SW corner of the area covered. The problem is that even for a six character locator, this can be rather more than 7km from the actual QTH. To minimise the error, one needs to return the co-ordinates of the centre of that area rather than the SW corner.
As an example of this, take my mother's QTH. Her actual co-ordinates are 53º2'19 N, 0º4'53 E which corresponds to JO03AA. Taking the SW corner of that locator, we get 53º0'0 N, 0º0'0 E which is some 6.9 km away. However, taking the centre instead, we get 53º1'15 N, 0º2'30 E which is only 3.3 km away, less than half the distance.
The conversion between the two is simply the addition of a fixed offset to both the final latitude and longitude - 1'15 and 2'30 respectively when a six character locator is given, and 30' and 1º respectively when only a four character locator is given. As a result, there is no real time penalty for doing so as far as code execution time is concerned.
Best wishes from Riley G7GOD / KB8PPG
Edited by - rhw2 on 01/04/2003 05:23:20 AM
VHF Locator check
Winlog32 never did calculate to the corner on the large square e.g. IO91 (IO91AA) for a four figure locator, and heading/QRB is taken to near centre of the square unless a 6 figure locator is added.
I see your point an the small square but think the differences would not make much practical difference.
73 Colin G0CUZ
Winlog32 Author
I see your point an the small square but think the differences would not make much practical difference.
73 Colin G0CUZ
Winlog32 Author
VHF Locator check
Hi Colin.
quote:Winlog32 never did calculate to the corner on the large square e.g. IO91 (IO91AA) for a four figure locator, and heading/QRB is taken to near centre of the square unless a 6 figure locator is added.
I'm glad to hear that.
quote:I see your point an the small square but think the differences would not make much practical difference.
If all locators were perfect rectangles of the same size, then it would make no difference whatsoever. The problem is that they aren't - whilst they all have roughly the same height N-S, they differ considerably W-E.
There are two problem cases:
When the source and target locators are given with different precisions. This is primarily a problem that is outside the control of the software though.
When the source locator is considerably narrower than the target locator since the resultant bearing variation (especially with 4 character locators) can be wider than the aerial beamwidth. Certainly on the microwave bands, aerials with beamwidths well below 1 degree are not unusual.
In the extreme cases, a ham located at either the north or south pole will see a variabce of 5 minutes of arc across the width of even a six character locator, and a full 2 degrees of arc across the width of a 4 character locator.
Best wishes from Riley G7GOD / KB8PPG
Edited by - rhw2 on 06/04/2003 09:12:39 AM
quote:Winlog32 never did calculate to the corner on the large square e.g. IO91 (IO91AA) for a four figure locator, and heading/QRB is taken to near centre of the square unless a 6 figure locator is added.
I'm glad to hear that.
quote:I see your point an the small square but think the differences would not make much practical difference.
If all locators were perfect rectangles of the same size, then it would make no difference whatsoever. The problem is that they aren't - whilst they all have roughly the same height N-S, they differ considerably W-E.
There are two problem cases:
When the source and target locators are given with different precisions. This is primarily a problem that is outside the control of the software though.
When the source locator is considerably narrower than the target locator since the resultant bearing variation (especially with 4 character locators) can be wider than the aerial beamwidth. Certainly on the microwave bands, aerials with beamwidths well below 1 degree are not unusual.
In the extreme cases, a ham located at either the north or south pole will see a variabce of 5 minutes of arc across the width of even a six character locator, and a full 2 degrees of arc across the width of a 4 character locator.
Best wishes from Riley G7GOD / KB8PPG
Edited by - rhw2 on 06/04/2003 09:12:39 AM