[AMRadio] [Glowbugs] Re: Kenwood TS-440S tuning knob binding

[Larry Szendrei]

On 6/24/18 12:12 PM, Tom Bridgers wrote:
> Larry,
> Coupla questions:
> What caused the binding that couldn’t be addressed by just disassembly and lubing?
>
> For current 440s owners, what should they do to prevent this binding from occurring in the future? IOW is there some preventative maintenance that needs to de done?  Annually ? Periodically?
>
> Was also wondering why you chose to lube with 3-in-1 oil versus other oils, such as Mobil 1 (which I prefer to use on my R-390a gear-trains).
>
>   I’ve read about more expensive lubricants that “adhere” to gears and shafts better, but still are sold as a viscous, oil. Not sure if those would apply in this situation, and I don’t have any personal experience with them...
>
> I really enjoyed your write up on how you solved the problem.  Many thanks for sharing...
> 73,
> -tom
>

Hi, Tom,

My answers to your questions:

 1. I don't know exactly what caused the binding, but I assume the
    shaft/bushing were dry after all these years, and when I was
    spinning the knob so much looking for QSOs in the recent June VHF
    contest it got warm from friction, and galling bound it up tight.
    (See https://en.wikipedia.org/wiki/Galling for a definition of
    galling.) I don't know if the original encoder can be repaired or
    not, but I didn't need to go there because I was able to find a
    replacement at a reasonable price. I'm saving the old one and maybe
    I'll look into it someday. Repairing it may well be beyond the
    capability of mere mortals.
 2. The reason I chose 3-in-1 oil is simple: it was the only light oil I
    already had on hand. Clif recommends Singer Sewing Machine oil; from
    his experience he thinks it's a better choice. I imagine it would
    help to lube the surfaces periodically, as long as any excess oil
    doesn't end up inside the encoder. How often? I don't know, but
    probably more often than once every 30 years!

Glad you enjoyed my summary. I wanted to answer some of the questions 
which I had before I started and during the replacement, in case others 
found themselves in the same "bind" (pun intended).

73,
-Larry/NE1S