RadioBanter - View Single Post - high quality graph of nice 0-100 analog scale?

February 18th 04, 07:07 PM

In article ,
(SpamLover) writes:

Is there any place on the web whence I can download some
high-definition graph for a 0-100 or 0-180 scale? I'd print it out in
large format and then reduce it to the size I need by means of an
ANALOG photocopier.

Here's some alternates -

Office Depot and Office Max chains have "graph paper" with
many kinds of scales...1, 2, 3, and 5 decade log scales by
linear or log on the opposing axis.

Analog-copy an old slide rule's C or D scales...themselves
fairly accurate single-log. [not many slide rules in common use
nowadays, heh heh, would be a fitting sayonara for them]

To actually draw one's own scale, get access to an old T-Square
(ancient drafting implement) and lay out a right triangle. Let a
large log scale be the hypotenuse (that side of the triangle on a
slant). Use the T-Square to get parallel vertical lines intersecting
marks on the log-scale hypotenuse to the horizontal (or vertical)
axis. The size reduction from original log scale to the new one
depends on the angle of the hypotenuse...very easy to "calibrate"
to start the marking.

Digital copying will depend on the quantization error of the number of
available pixels in the image. Most pronounced in absolute black-
and-white mode. Greyscale and color will show up in gradations and
one has to guess at the exact point of the log markings.

For very fancy dials, most industrial-strength photo shops can handle
up to 4x original art (perhaps to 11" x 14"), shoot it, reduce it to
very-close-to-desired dimension, and even opaque any clear spots on
the negative. That method can be the basis for a chemical etching of a
metal dial. Cost varies so it is best to inquire first on that method.

Len Anderson
retired (from regular hours) electronic engineer person

Yes, I've done a few things like the above, including round back-lighted
circular tuning dials. :-)