Garmin 430 question

Marco Leon wrote:
"Sam Spade" wrote in message
...


You got me wondering whether the 530W did user waypoints differently, so I
downloaded the 530W manual.


Page 136:

"To create a new user waypoint by entering its latitude/longitude
position"

Page 137:

"To create a new user waypoint by referencing an existing waypoint" This
procedure uses radial/distance from the existing waypoing.


This is the page on 137. The manual is probably referring to a VOR as a
waypoint. #4 states: "Use the small and large right knobs to enter the
identifier of the reference waypoint. The reference waypoint can be an
airport, VOR, NDB, intersection or another user waypoint. Press ENT to
accept the selected identifier."

If you look at the note in the next column on page 137 it states, " The
second reference waypoint field (REF WPT) is a temporary reference only -
not a reference that is stored with the user waypoint. You may also use this
in conjunction with the first reference waypoint to create a position using
the intersection of two radials."

Marco



I missed that note. But, that note is somewhat different in the 530
manual because not reference is made to creating a position using the
intersection of two radials.

So apparently this radial/radial option was a new feature in the WAAS
series.

"Sam Spade" wrote in message
news
Marco Leon wrote:
I missed that note. But, that note is somewhat different in the 530
manual because not reference is made to creating a position using the
intersection of two radials.

So apparently this radial/radial option was a new feature in the WAAS
series.

The functionality is in the 530 (A) but it's not explicitly stated in the
old manual. There is a note in that section but the statement about using
two radials to create a user waypoint is not there.

Marco

Marco Leon wrote:
"Sam Spade" wrote in message
news
Marco Leon wrote:
I missed that note. But, that note is somewhat different in the 530
manual because not reference is made to creating a position using the
intersection of two radials.

So apparently this radial/radial option was a new feature in the WAAS
series.


The functionality is in the 530 (A) but it's not explicitly stated in the
old manual. There is a note in that section but the statement about using
two radials to create a user waypoint is not there.

Marco


Thanks for your help.

Indeed it does work in the 530 trainer. I guess I was hung up on the
reference waypoint changing after I created the intersection. The
handbook says that doesn't matter, which of course it doesn't. ;-)

The 530 and the 530W created a slightly different position for the
intersection of V-264 and V-137.

And, the official FAA position is slightly different than those two.
The difference is reasonable for an en route airway intersection. I
wouldn't want to be designing IAPs using this method, though. ;-)

Intersection of V-264 and V137:

FAA:

34 05 49.9
116 54 33.8


530:

34 06 02.0
116 54 50.7


530W:

34 06 01.9
116 54 50.2

It would be interesting to construct this waypoint at a location with a
different mag var than the location I used and see if that would affect
the device's calculation. Next time.

"Sam Spade" wrote in message
...
Thanks for your help.

Indeed it does work in the 530 trainer. I guess I was hung up on the
reference waypoint changing after I created the intersection. The
handbook says that doesn't matter, which of course it doesn't. ;-)

Out of curiousity, I opened my 430W manual last night and it turns out that
the note about using two radials to generate a user waypoint is NOT in my
version. It states, "The second reference waypoint field (REF WPT) is a
temporary reference only-not a reference that will be stored with the user
waypoint. By default, this field will display a radial from the nearest VOR.
However, you can select any waypoint-by identifier-to use as a reference in
this field."

So it seems Garmin is not consistent in documenting this function despite it
identical operation in both units. I see why it threw you for a bit of a
loop. Using the above note I would expect the secondary reference waypoint
to change with no further functionality possible.

The 530 and the 530W created a slightly different position for the
intersection of V-264 and V-137.

And, the official FAA position is slightly different than those two.
The difference is reasonable for an en route airway intersection. I
wouldn't want to be designing IAPs using this method, though. ;-)

That's interesting. I wonder what the error works out to be. The difference
between the 530 and 530W is even more intriguing. I wonder if the difference
is a function of the software logic, the database version or both.


Marco

I've wondered how closely the radial projected by a GPS matches the radial
indicated by a perfectly accurate VOR receiver. Does a sophisticated GPS
have a database that compensates for VOR misalignment due to movement of the
magnetic north pole over time?

On Jul 22, 1:23*pm, "Jon Woellhaf" wrote:
I've wondered how closely the radial projected by a GPS matches the radial
indicated by a perfectly accurate VOR receiver. Does a sophisticated GPS
have a database that compensates for VOR misalignment due to movement of the
magnetic north pole over time?

Well. there is a great answer to this conundrum!

If you are in regular "desired track" mode, the GPS box applies a
computed,
local declination value to locate magnetic north.

If you go to OBS mode, the GPS box applies the actual
magnetic correction for that particular VOR.

Most of the VORS need to be twisted to real magnetic north
these days, so there will be a difference.

So if you are using OBS mode to overlay a victor airway you will be
fine,
as the V airways are predicated on lining up real magnetic bearings
from VORs.

Smart things, these boxes.
I'm sure all this is due to global warming.

Bill Hale BPPP instructor

Your answer was right but you missed the question.

--
Regards, BobF.
"Bill" wrote in message
...
On Jul 22, 1:23 pm, "Jon Woellhaf" wrote:
I've wondered how closely the radial projected by a GPS matches the radial
indicated by a perfectly accurate VOR receiver. Does a sophisticated GPS
have a database that compensates for VOR misalignment due to movement of
the
magnetic north pole over time?

Well. there is a great answer to this conundrum!

If you are in regular "desired track" mode, the GPS box applies a
computed,
local declination value to locate magnetic north.

If you go to OBS mode, the GPS box applies the actual
magnetic correction for that particular VOR.

Most of the VORS need to be twisted to real magnetic north
these days, so there will be a difference.

So if you are using OBS mode to overlay a victor airway you will be
fine,
as the V airways are predicated on lining up real magnetic bearings
from VORs.

Smart things, these boxes.
I'm sure all this is due to global warming.

Bill Hale BPPP instructor

Marco Leon wrote:
"Sam Spade" wrote in message
news
Marco Leon wrote:
I missed that note. But, that note is somewhat different in the 530
manual because not reference is made to creating a position using the
intersection of two radials.

So apparently this radial/radial option was a new feature in the WAAS
series.


The functionality is in the 530 (A) but it's not explicitly stated in the
old manual. There is a note in that section but the statement about using
two radials to create a user waypoint is not there.

Marco


Thanks for your help.

Indeed it does work in the 530 trainer. I guess I was hung up on the
reference waypoint changing after I created the intersection. The
handbook says that doesn't matter, which of course it doesn't. ;-)

The 530 and the 530W created a slightly different position for the
intersection of V-264 and V-137.

And, the official FAA position is slightly different than those two.
The difference is reasonable for an en route airway intersection. I
wouldn't want to be designing IAPs using this method, though. ;-)

Intersection of V-264 and V137:

FAA:

34 05 49.9
116 54 33.8


530:

34 06 02.0
116 54 50.7


530W:

34 06 01.9
116 54 50.2

It would be interesting to construct this waypoint at a location with a
different mag var than the location I used and see if that would affect
the device's calculation. Next time.

Sam Spade wrote:
Marco Leon wrote:

"Sam Spade" wrote in message
news
Marco Leon wrote:
I missed that note. But, that note is somewhat different in the 530
manual because not reference is made to creating a position using the
intersection of two radials.

So apparently this radial/radial option was a new feature in the WAAS
series.



The functionality is in the 530 (A) but it's not explicitly stated in
the old manual. There is a note in that section but the statement
about using two radials to create a user waypoint is not there.

Marco

Thanks for your help.

Indeed it does work in the 530 trainer. I guess I was hung up on the
reference waypoint changing after I created the intersection. The
handbook says that doesn't matter, which of course it doesn't. ;-)

The 530 and the 530W created a slightly different position for the
intersection of V-264 and V-137.

And, the official FAA position is slightly different than those two. The
difference is reasonable for an en route airway intersection. I
wouldn't want to be designing IAPs using this method, though. ;-)

Intersection of V-264 and V137:

FAA:

34 05 49.9
116 54 33.8


530:

34 06 02.0
116 54 50.7


530W:

34 06 01.9
116 54 50.2

It would be interesting to construct this waypoint at a location with a
different mag var than the location I used and see if that would affect
the device's calculation. Next time.