N S E W

[michael feist]

Some time ago a came across a 'compass' in a recycling shop. I bought it for, I think, £5. 1t looked brand new and had a number of additional features that I had not seen before. On the reverse side had columns on information, with what seem to headed in German.
Will attempt to photograph both sides and paste here shortly. But having some trouble with 'smallerizing' the image, so...
The question is, what do the terms etc in the tables mean?

Winkel
0-360°
angle
(beneath this heading are numbers 1 to 50)

Winkel
0-6400
angle
(beneath this heading are a numbers 18 to 889)

Stelgung
%
gradient
(beneath this heading are the numbers 2-120)

Breite/Entfernung
Width/
distance
(beneath this heading are a series of fractional numbers from 1/60 to 1+ 1/5)

(These columns are labelled Ⅰ Ⅱ Ⅲ Ⅳ)

There is a threaded hole underneath so that it can be mounted somewhere.
It is painted in olive green / khaki and each opposite edges if case carry inch measurements (two inches) one and 5 cm on the other).

I will try again to photograph and print here! What does it all mean?
Regarding mf.

[michael feist]

WIN_20230508_09_29_47_Pro.jpg (38.68 KiB) Viewed 135 times

And also, I hope, the reverse side...shortly. Mf.

[michael feist]

WIN_20230508_09_34_56_Pro.jpg (35.26 KiB) Viewed 133 times

And hopefully,

WIN_20230508_09_34_56_Pro.jpg (35.26 KiB) Viewed 133 times

. Mf

[David Frydman]

Winkel as in weitwinkel means, I think, angle and wide angle.

Their are about 6283 milliradians in a circle.

1000x 2Pi.

However, Nato use 6400, Warsaw pact 6,000 and Sweden 6,300.
This is to make division easier on artillery sights, compasses etc.

Apparently Swiss 6400 so called mils are measured from true or compass north?

There are 100 grads in a right angle, maybe Greek or 400 grads in a circle.

% inclination is self explanatory.
I have a cheap inclinometer with this. Some have batteries.

Mike, your compass seems to be a 1900s artillery man's compass.

Binocular reticles are usually marked in mils or milliradians.

Regards,
David

[David Frydman]

The 7.2 degrees for 1 to 50 is a mystery.
Perhaps the angular field of a Nato binocular.

The 6400 'mils' seem to be a similar size.

The 2 to 120 for inclination I cannot think of a reason.
Perhaps the field of a sighting telescope?

Regards,
David

[David Frydman]

Width over distance gives the angle.

So, if both are known maybe these fractions transpose to the angle columns.

1/60 to 1 +1/5 again brings in 72 or ten times 7.2.

I think one looks across all four columns to get equivalents, but maybe with the units not quite clear unless one has instructions.

I suppose the mounting hole is 1/4 inch Whitworth.

Regards,
David

[David Frydman]

1/10 mrad is a common click size for adjusting sights.
This probably is reflected in the 72 rather than 7.2 degrees.

Finland used 6000 'mils' but has switched to 6,400 'mils'.

Sweden has switched from 6300 to 6400 'mils',

The 2-120 may be because the drop was calculated as half that at 100 metres range.

So the compass seems to be a standard Nato compass perhaps made in Germany.

However, I don't know how the reticles on binoculars and other instruments are marked.
Are they all real mrads or the variations for different countries?

Regards,
David

[David Frydman]

Perhaps the 2-120 is 1-60 mrads of inclination of the sight for the drop at distance.

Regards,
David

[michael feist]

Thank you so much David! What a mass of information, much of which I will need to study to take in all in. Regards mike f.

[David Frydman]

The 2-120 might be 1-60 x 1/10mrad.

1/10 mrad is usually one click on the sights or 1cm at 100m.

1/10 mrad is 20.6 arcseconds or about the size of Saturn's disc or half Jupiter's disc.
Someone with excellent eyesight might detect this especially if some vernier acuity is used.

On binoculars the increments are sometimes 5 or 10 mrads.
A real mrad is about 3.5 arcminutes.

With small increments the approximation of 6,400, 6,300 or 6,000 seem to be O.K.

Swedish binoculars were either home made or made by Zeiss and possibly others.
6,300 is very close to the 6283 real mrads.

But does this mean Komz binoculars, say the common 8x30, have more than 6% different reticles to Nato binoculars, or are the reticles real mrads?
Besides the difference of over 6% there are individual errors, which might result in an 8% error.
That is plus say a 5% user error.

Regards,
David