Re: '71 squareback clock repair

[stans4@ix.netcom.com]

My original clock was the transistorized sort.  I tore into it and found that the oscillator coil was open.  Measuring the wire on the coil, I found it was about 44-46 AWG, kind of hard to get really precise when it's finer than hair.  I started unwrapping the coil, I've been able to salvage meter movements if the break is near the surface.  The break was too far down so I scrapped the project.  I then went to a scrapyard, was shown a large box of clock take-outs. $5 each, take my pick. I got one of the earlier types that's basically an electrically wound spring-driven clock.  It had a metal cover on the back, the original '71 vintage one was plastic.  It didn't work initially, there was a low-melting point alloy plug bridging two little spring fingers, probably as an internal fuse in case the contacts stuck.  A little solder fixed that.  The contacts were cleaned with a relay burnishing tool.  This clock had seven jewels! First time I'd ever seen an auto clock with a jeweled !
!
movement and an Incabloc type pi
vot jewel on the balance, too!.  A little cleaning with some alcohol on the pivots followed by relubrication with some high-speed dental turbine oil and it kept remarkably good time as long as the temerature was constant.  It's slow in winter and fast in summer, spring and fall it keeps good time.

I've not seen one of the transistorized sort working, so I can't say how good a time they keep, the innards were about on a par with contemporary American car clocks, which is to say pretty cheap.  Both sorts are based on an enlarged watch movement, a good library can supply some basic repair manuals on clocks and watches.  What usually happens on the electrically wound sort is the contacts stick and either the coil burns out or it blows a fuse(like mine).  The diode across the solenoid coil that a previous poster mentioned sounds like a good idea, I'll do that next time I have it out.