[TenTec] MUSHY KNOBS

[Douglas]

> 
> Date: Wed, 17 Aug 2005 13:37:05 -0500
> From: "Ed Worst" <edworst at att.net>
> Subject: [TenTec] MUSHY KNOBS
> To: "TenTec Contesting" <tentec at contesting.com>,
> "TenTec List"
> 	<Tentec at mailman.qth.net>
> Message-ID: <000501c5a35a$c0b1f780$0100a8c0 at RNR99>
> Content-Type: text/plain;	charset="iso-8859-1"
> 
> I've noticed for some time that some of the switches
> on my TenTec gear seem
> to be, well, mushy.  The Mode Switch and the Band
> Switch are especially
> prone to this.
> 
> It turns out it's the knob, not the switch, and the
> problem is that if you
> overtighten the setscrew, the inner circle of the
> knob cracks and doesn't
> maintain a firm grip on the shaft.  Take one of
> those knobs off and look at
> the underside and you'll see what I mean.  There's a
> circular gap between
> the inner circle which fits the shaft and the outer
> circle which is where
> the body of the knob begins.  (Seems like a poor
> design, given the function
> of the knob.)
> 
> I thought that if I filled in that gap in the knob,
> it would make the knob
> solid and less likely to crack when the setscrew is
> tightened.  So I tried
> some J-B WELD as filler, and it worked.  First, I
> had to restore the inner
> ring to its original position.  This was done with a
> flat wooden toothpick,
> but other items will work also.  Just don't plan on
> re-using this spacer
> because it'll become a permanent part of the repair.
>  Mix about a 1 inch
> stripe of Part A and Part B of the J-B WELD
> together, and carefully fill in
> the gap.  The J-B WELD has the consistency of
> toothpaste, so you'll have to
> work it down into the gap.  I used another flat
> toothpick to do this.  Wipe
> off any stray epoxy before it sets.  The package
> recommends a 15 hr cure
> time, and I'd recommend following this
> recommendation.  The last thing you
> want is to apply any stress to the epoxy before it's
> fully cured.  By the
> way, I chose J.B. Weld because it seems to be
> readily available at any
> autoparts store, and also because the description on
> the package states, in
> part, "The city of Dallas, Texas repaired a cracked
> Caterpillar engine block
> with J-B WELD and saved $4,000.00 plus 30 days down
> time."  If it's good
> enough for that, it should be good enough for
> plastic knobs.
> 
> So, if you have this "mushy knob" problem, give J-B
> WELD a try.  It works
> for me.
> 
> 73,
> ed - k9ew

Jeez,

What are you guys doing to those poor knobs?
Are you tightening the set screws to 50 ft.lbs. of
torque??

I've owned about 8 Ten-Ten rigs, for as long as 15
years, going back to the Triton IV, Omni-D, Corsairs,
Corsair II, Centruy 21, etc and have never broken a
knob or had one loosen enough to notice.

Doug/WA1TUT