[Hammarlund] SP-600 dial slippage

[James A. (Andy) Moorer]

There is the "don't put goo on it" school, and the "do whatever works"
school. If the procedure outlined below still yields a slipping dial, and if
you are of the "do whatever works" school, try this - it is 100% effective:

Go to the local music store and get a rosin block for violin. They will ask
what kind. Ask for the cheapest. It should be maybe $2.50. CAREFULLY apply
it to the outer edge of the small brass flywheel (the one about an inch
across) and to the outer edge of the vernier dial itself. I guarantee it
will never slip again.

The only real downside of this is that when you get to the end of the dial,
instead of slipping smoothly, it will shudder and vibrate a bit - sorta like
a violin.

If you decide it was a bad idea, a bit of cleaning fluid will take it right
off.


-- 
www.jamminpower.com
James A. (Andy) Moorer






on 6/15/02 3:32 PM, lou at lou.de.beer@general.com wrote:

> I recently acquired a pristine SP-600 that has the common dial slippage
> problem.Here are some things to try.
> 
> 1.Carefully clean the edge of the dial,the friction wheel(the small one) and
> the flywheel..You will be suprised the junk that is on the surfaces..I used
> isoprophyl alchohol some cotton and a tooth pick.
> 
> If slippage persists more drastic measures are necessary.Next remove the
> front panel a bit of of a job.Put the radio on its back.The side panels rear
> extensions will clear the fuse cover etc on the back apron.Next remove the
> brass trapezoidal section that holds the bandswitching mechanism shaft.Next
> remove the vertical metal section that has the band dial attached..You now
> have access to the dial drive mechanism..You will see that the small
> friction wheel is seated in a three point bearing that "floats" under
> tension of the hairspring..Make sure the spring is intact and properly
> seated in the small holes Carefully move the flywheel a bit..You will need
> to hold the flywheel since it is not supported without the previously
> removed sections..Don't move the dial too much..The anti-lbackash gear on
> top of the gear train is now unsupported and moving it too much can damage
> the main dial gear train...At this stage you can further disassemble the
> gear train to clean and lubricate the bearings but DON"T LUBRICATE the gears
> themselves...This is not a job for the fainthearted but well worth it..I
> have some pictures for those who are interested...Lou ND6W
>