[R-390] Gearbox

[Flowertime01 at wmconnect.com]

Graham, 

You commented, 

I have two EACs, one of which I have given a full strip and cleaned, the 
other
just a cotton bud and relube type of service. The one which has been
completely stripped I can turn with just my little finger in the
flutes of the knob. The relube one needs an index finger. I used ISO
68 machine tool slideway oil on both.

-----
Even here you have two EACs which we would think were of equal quality 
parts. We would think that after a good cleaning one way or another and relube 
that they would act equally good.

 All it takes is one sorry gear set, and who knows what pair it will be in 
any receiver. It could just be a miss punch in a bearing location from some 
dust in the index jig. 

Pull the VFO out of the stiff one and see how the gear train feels. Often 
as not the bearing in the front of the VFO is a stiff point. Pulling that 
item apart and cleaning it is more work than most of us want to take on. But 
some "dry cleaning" will often reduce the friction.

Often just one bearing point not cleaned well will increase the friction. 
This is why often the full tear downs with carefully eye ball for grime 
produces a better low friction gear train than just the bath over the edge of the 
bench produces.

Roger AI4NI
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