[Heathkit] removing LMO knob on SB series radio

[Chris Kepus]

Gerry,
Bill already hit on a couple of very helpful suggestions. I will only add my
thoughts to his:

Suggestions:
1. Hit the Qth.com list archives and search for "stuck knob", "frozen
knob",etc.  You're neither the first or last that will come up against this
problem.
2. Procure a Xcelite LN-22 5/64 Allen driver (better yet, treat yourself to
a complete set of these) -  I just removed a SB-401 LMO knob with very
resistant set screws to verify the Allen bit size.  These Xcelite drivers
allowed me eventually remove knobs from a BC639 that I was parting out. I
have never encountered a more challenging knob removal task as every one of
those dang knobs was frozen hard on it's shaft. When the Xcelite twisted
almost 90 degrees and the knob didn't give up, I started a process of using
a top notch penetrant (PB Blaster, Liquid Wrench, or my fav: 1/2 Acetone +
1/2 ATF) that I applied with one of the plastic tube extensions that come
with spray cans - just used the tube to dip into the penetrant, then slipped
the tube into the set screw recess with a drop of pentrant a couple of times
and let it soak.  None of the knobs gave up in a 3 day period.  Then, with
the Xcelite twisting away and after four days of soaking, they started
giving up...the last knob took two weeks of daily twist and daubing of
penetrants!!!  I thought for sure the Xcelite bit would break but it never
did. Never had a tool that took so much abuse and lived to tell about it.
With many BA's to service, one of my best investments.  YMMV.
73 and good luck,
Chris
W7JPG

-----Original Message-----
From: Heathkit [mailto:heathkit-bounces at mailman.qth.net] On Behalf Of Gerry
Steffens
Sent: Friday, April 03, 2015 1:10 PM
To: 'Heathkit2 '
Subject: Re: [Heathkit] removing LMO knob on SB series radio

OK.  So somebody took a pipe wrench to the hex wrench when they assembled
this equipment.  They tightened the LMO knob so as to hold off a herd of
charging elephants!  Or, is this the result of flowing aluminum coupled with
corrosion?  Everything appears clean & shiny.

Now, I want to take the LMO knob off.  I have the appropriate hex wrench.
To get down in to the set screw I must put the long end down into the knob.
My fingers can't turn the wrench without filleting my fingers.

Is there a secret to undo this without wrecking things?  Dare I use a pliers
or other tool on the wrench?

Any suggestions would be most appreciated.

TIA

Gerry



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