[ARC5] R-25 dial nonlinearities

[Kenneth G. Gordon]

On 8 Jan 2017 at 15:50, Michael Bittner wrote:

> The HP 204C audio sig gen uses elliptical gears to achieve a linear
> dial scale. Picture the small radius end of the dial gear meshed with
> the large radius side of the capacitor gear and you can see how one
> gear speeds up or slows down depending on the mesh point. 

Yes. I have a 204C. Very interesting.

> The Remler 631 "butterfly" variable capacitor has square shaped plates.  Each set of plates (two 
> rotors, no stator) rotates at one corner and are both geared to a central dial shaft to mesh and 
> unmesh with each other.  This action produces the sum-of-the-squares for linear frequency 
> change with dial rotation.

Now THAT is truly ingenious!!!! :-)

And even us klutzy hams could do that one.
  
> None of this applies to ARC-5, but interesting anyway.  Mike, W6MAB

Yes. Very. Thanks,

Ken W7EKB

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