[NLRS] 10 mile rule (WAS: dupe sheet specs)

[Bruce Richardson]

Please don't think that by my post that NLRS is a 10Gig only club!  :-)

I just think the VHF rules are pretty good and steady (except for Rover but
that horse is dead).

I think it would be just fine if we could articulate our need for
clarification of the 10mile rule to the contesting division and the VUAC.
Sure, there are answers, changes, or clarifications we would like less than
others. But a clearer rule will not have us debating locally as to what is
appropriate. And operating on an email clarification by Billy Lunt really
isn't satisfactory either.

Locally, we have discussed this topic a great deal over the years. We even
have differing opinions locally. I bet we could put together a package on
the need for a clearer rule, and some potential solutions, and their
varying ramifications.  I think it's one way that NLRS could help lead the
way.

Sure, other VHF clubs, when approached about this topic will have glazed
eyes because they don't have a 10G component locally.  But a few clubs
nationally should care a great deal.  And yes, their view may be different
than any consensus we built locally.

So, let's keep the discussion going either on or off reflector.

73
Bruce Richardson W9FZ

-----Original Message-----
From: Baker, Donn B [mailto:Donn.Baker at UNISYS.com]
Sent: Friday, September 22, 2006 8:19 AM
To: nlrs at mailman.qth.net
Subject: RE: [NLRS] 10 mile rule (WAS: dupe sheet specs)




Duh!
A simple-minded arithmetic error in the diagonal numbers below... I did
SQRT(x*y) and NOT SQRT(x^2+y^2).  Dumb!

The correct numbers are:
Sub-Sq size
at:						Max diagonal
54° = 	2.88 mi x 2.94 mi		4.12 mi
45° = 	2.88 mi x 4.07 mi		4.99 mi
24°30' = 	2.88 mi x 4.55 mi  	5.38 mi

73 Donn
WA2VOI/0

-----Original Message-----
Sent: Thursday, September 21, 2006 6:11 PM
Subject: [NLRS] 10 mile rule (WAS: dupe sheet specs)

A sub-square is 2.5 minutes of arc of latitude(N-S) by 5 min of arc of
longitude (E-W).

One (1) min of arc of latitude = 1 nautical mile (by definition), and for
practical purposes is constant from pole to pole. (Yes, the earth is not a
sphere, but its close enough.)

The physical length of 1 min of longitude varies from '0' at either pole,
to 1 nautical mile at the Equator.  Therefore, the length of 1 min of arc
of longitude at any latitude is 1*cos(lat).

Here in MPLS (45°N), this works out to 0.707, so the EN35ja sub-square (for
example) is 2.5 NMiles N-S and 5*0.707=~3.54 NMiles EW.  (Ok, OK. A NMile
is 6076.8' or 1.15 Statute miles, so EN35ja is ~2.88 x 4.07 miles.)

So what does this mean re: Doug's comments ?
The southern most part of the US (Key West, FL) is about 24° 30' N (and
about the same as Baja CA.)  The northern most part of the US (Angle Inlet,
MN) is 49° 30' (give or take). But, Canada is more northerly than that, so
lets go north of Edmonton, AB, or 54°

Sub-Sq size
at:						Max diagonal
54° = 	2.88 mi x 2.94 mi		2.91 mi
45° = 	2.88 mi x 4.07 mi		3.42 mi
24°30' = 	2.88 mi x 4.55 mi  	3.62 mi

The MAXIMUM difference, then, is 4.55-2.94 or 1.61 miles, E-W. This is ~16%
of the minimum valid move between operating locations between the MAXIMUM
northern and southern positions.

Note that it's very, VERY difficult to make a valid move with-in ANY
sub-square.  I'd say impossible, even given road miles vs. air miles.

73 Donn
WA2VOI/0

At 10:26 21-09-06 -0500, Doug Reed wrote:
>
>
>Last weekend we discussed the 10 mile rule a couple times during meals.
>Every time I suggested that sub-grids be used as part of the
>determination, I was told they don't matter but here we are using them
>to check for dupes.<g>
>
>I'd still like to have the rule changed to something like "every new
>operating location must be a minimum 10 road mile move from the last
>operating location and every QSO must be from a different 6-digit
>sub-grid." This does penalize the southern states where sub-grids are
>larger, but I'm not sure how much the actual difference is.
>
>73, Doug Reed, N0NAS.


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