[Hammarlund] SP-600 Knob and tag removal help!

Mon, 27 Jan 2003 06:58:58 -0500

Hi Cecil, sorry you had such trouble with the knob... I'm sure some anxious
moments - been there, done that, have the tee shirt!

I missed your original post, but suspect the knob in question is the
bandswitch.   I had a similar problem with the tune & load controls on a
KWS-1. What's in common is that the knobs are heavily tightened because of
the high torque needed. On the KWS-1, overtightening ruins the knob causing
binding in it's turns-counter mechanism, causing the need to be tighter -
Catch-22.

Anywho, to make a long story short.  Consider grinding or filing a small
flat-spot on the shaft. This gives the setscrew a much better purchase,
increases the torque handling considerably, and any burring which may result
is recessed below the diameter of the shaft away from the collar of the
knob.

I reburbed an SP-600 some years ago, came out wonderful.  Best of luck with
your project.

73, Bill
~~~~~~~~~~~~~~~~
Bill Coleman    N2BC
http://home.stny.rr.com/n2bc
----- Original Message -----
From: "Cecil Acuff" <[email protected]>
To: <[email protected]>
Sent: Sunday, January 26, 2003 8:29 PM
Subject: Re: [Hammarlund] SP-600 Knob and tag removal help!

> Greetings,
>
>
>         I did get the knob off today...had to resort to the dreaded drill.
> Filing down larger Allen wrenches and driving them in only resulted in
> stripped shoulders on the Allen wrench.... I drilled it out progressively.
> I used one that got most of the meat leaving a very thin shell of the set
> screw.  I then moved up a size to thin it out further and finally cleaned
> out the last of it with the next larger size.  I did take all but the
> deepest part of the threads out of the brass insert.  I plan to drill and
> tap that to the next size set screw anyway.  Still couldn't get the knob
off
> the shaft....it would spin but not slide off.  I finally got the knob off
> with lots of pulling but left the pressed in brass insert on the shaft.  I
> had to finally wedge a thin adjustable wrench between it and the front
panel
> to pop it off.  I drove it back into the knob once doing a careful
alignment
> with the threaded holes in the knob and all is well.  No damage to the
knob
> or shaft except for a small dimple in the shaft where the drill bit hit
it!
>
> Once I had the radio on it's side to work on the knob...I noticed the tag
> had enough room to get a fingernail underneath one corner.  The thing
> virtually fell off in my hand....how lucky can you get!
>
> So I am good to go with the panel refinishing...first one of
these...should
> be lots of fun!  Got a little pitting and corrosion to deal with.  Ought
to
> be interesting.  I'll let you know how it goes!
>
> Thanks again to everyone!
>
> Cecil Acuff
>
> ----- Original Message -----
> From: Cecil Acuff <[email protected]>
> To: <[email protected]>
> Sent: Sunday, January 26, 2003 3:50 PM
> Subject: [Hammarlund] SP-600 Knob and tag removal help!
>
>
> > Thanks to all who responded to my notes for help....I have had several
> good
> > suggestions and will be implementing in the next few days....I'll let
you
> > know how it "comes out"  or off as it may be!
> >
> > Thanks all!
> >
> > Cecil Acuff
> >
> >
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