[R-390] Corrector plate PTO's, was Re: Another "Close to Perfect" R-390a

[Roy Morgan]

At 10:58 AM 3/2/2006, you wrote:

>I just googled for "R-389" and PTO and found Don Reave's pictures
>of the internals of a 70H-1.

  I found that at: http://www.r-389.com/


>What's the typical "range" of correction?

I have not done a corrector stack adjustment, but:

Seems to me that the range of the stack plates is way less than one quarter 
turn, more like five or maybe 10 degrees of rotation.  The change of 
rotational position of the threaded part of slug mechanism imparted by the 
corrector mechanism is not very much.

Yes, the jump from one plate to the next cannot be too much, or the roller 
follower will not make the move.

As I understand it:
Each plate is separated from the next by a more or less fixed shim.  Thus 
you can move each plate independently of it's two neighbors.  The 
manufacturers had a jig with a PTO shield cut to allow entrance of a 
moveable set of jaws that could move one plate at a time. The stack of 
plates is locked by a bolt through the whole stack, or by some similar 
clamping mechanism.  The operation was: Move PTO to next plate, unlock, 
make correction, lock, then repeat 40+times.  Then do it all over 
again.  If *I* were setting up the ladies with linearization adjustment 
stations, I would automate the stack lock/unlock thing with a foot switch, 
and provide a very easy to read center-zero meter readout for each 25 kc 
step, and likely an automated turn-a-quarter-turn mechanism.

Roy



- Roy Morgan
National Institute of Standards and Technology
100 Bureau Drive, Stop 8970
Gaithersburg  MD 20899-8970
Voice: 301-975-3254  Fax: 301-948-6213
E-mail:  roy.morgan at nist.gov --