[Boatanchors] Anyone familiar with innards of a Collins R-390/URR PTO?

[Bob Young]

The end point adjustment inductor is held by a sleeve that fits snugly over it's full length but the inductor turns when I try to turn the adjustment, I cannot figure out how it is supposed to be held, were they glued? It appears someone tried to screw the inductor core in too far (not sure who could have done that, haha) Also looking for a PTO for this receiver that is within tolerance for sale, mine was about 3 kHz short end to end and most of that was within 300 khz at the low end, lousy
linearity. There are three for sale on the auction place but none of them have been checked for end point tolerance. I would not want to attempt taking a coil off one bring it within tolerance, this is not for an R-390A, thanks

Bob kb1okl