[R-390] SP 600 Wiring Colors

[Cecil]

I've been lucky not to have experienced that....yet.

Cecil

Sent from my iPad

> On Apr 30, 2014, at 8:11 AM, Tisha Hayes <tisha.hayes at gmail.com> wrote:
> 
> Funny,
> The one commonality I have seen with SP-600 wiring.. if you have even the
> slightest provocation, tear it out and replace it. Especially anything that
> penetrates to the front panel.
> 
> On the '600's I have known (I really cannot say love, they are like a
> stepchild that you just know is up to no good), the wiring insulation turns
> to a million little crunchy pieces as soon as you remove the front panel.
> This usually happens where the wiring goes through those rather sharp-edged
> circular holes in the lower chassis.
> 
> So you do the standard thing; sigh, snip off the wire lacing (and it was so
> pretty looking) gently work that one wire loose, unsolder it from whatever
> pot or switch it was attached to and thread on a thin piece of spagetti or
> heat-shrink tubing. Usually it takes an entire six to ten inch length of
> tubing and as you are going more of the insulation chunks are breaking off
> of that wire. Looking closely you see that many of the conductive strands
> are corroded and broken on that one wire. You bravely muddle along and now
> that wire looks all pretty.
> 
> Hmm, getting ready to re-bundle everything else and you find that you
> cracked insulation on three or four other wires while working on that one
> wire... Darn. Now the experience gets repeated on those too. This is
> turning into a day-killer.
> 
> Ok.... it is now 11:45 in the evening, you have done a half-dozen of those
> wires. A few times you find that the cracked insulation extends all the way
> into the lower chassis but you are set in your mind; "there is no way I am
> cutting apart the lacing in the lower chassis". Yea, keep thinking that,
> maybe it will help you sleep at night. Wait until you need to do something
> silly like replacing a bad paper cap or BBOD."
> 
> All this happens because you wanted to fix a slipping tuning dial. Maybe in
> your zest for cleanliness you disassembled the brass plate that retains the
> geartrain under the front panel so you could make the tuning bezels look
> pretty. (been there, done that) and you used brass cleaner to make all of
> that stuff look nice. Maybe you were really foolish and used something even
> in the slightest bit greasy so the edge of the tuning dial is slightly
> slippery so the brass wheel that is driven by the tuning knob is no longer
> gripping the edge tight enough (that is what usually causes a slipping
> tuning knob, weak hairpin springs, corrosion on the cadmium plated front
> pan and the little gear carrier that is supposed to be spring loaded
> against the edge of the display disk, all quite clever for its day.).
> 
> BTW, even though it caused me almost a week of grief, fixing other things
> that geartrain looks spectacular! I strongly recommend that if you have
> metal that needs to be polished, give "Simichrome Polish" a try. It smells
> ammonia based but things I have polished ten years ago still look brand new.
> 
> -- 
> Ms. Tisha Hayes. AA4HA
> 
> *this would be a good one;   ""In this denial of the right to participate
> in government, not merely the degradation of woman and the perpetuation of
> a great injustice happens, but the maiming and repudiation of one-half of
> the moral and intellectual power of the government of the world." --
> Fredrick Douglass"*
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