Did something on KLH Model 5 —help

[BernieH]

Hmm mine is broke just to the left of your arrow...the wire that must attach under the dust cap. Must have broken at the connection on the outer ring as it comes out of the dust cap, seems just long enough to connect and no partial strand coming from the solder point, your first picture also looks like that one had the same break but you had room to “sister” a wire between the upper and lower strand? Or am I seeing things?

thanks

 

[alteclipsch]

It comes out of the dust cap? I've not seen that, they come out of the cone, where they are free until they reach the outer edge of the cone. In my other ones the break has occured in the flex area and I just soldered the ends together after gentle scraping the varnish away and a bit of fluxing. See new arrow.

 

[BernieH]

Sorry, this is deeper than I’ve gone so not using the right description. Also, I don’t know how to draw an arrow but hope you can see the on the left the broken wire coming up. From what you have said (and thank you!!). I’ll try to clear off where it should be connected and see if I have enough slack to reattach? I’m old and my eyes seem to pay tricks on me when the wire is so very small — yikes

 

[alteclipsch]

Yup I see it, that's the area I've most seen and it's an easy repair if you have experience in vascular surgery. If not, it's a little more difficult, as it was for me.

My procedure was to very gently scrape about 1/8" of varnish away, flux the ends, place a bit of foil under the break to help keep the cone from burning, and have at it with a gun just hot enough to do the solder. You'll have a little ball of solder there after finishing, no big deal. A steady hand is an advantage, that wire is real skinny.

Really rewarding if you see continuity when you're done.

BTW, I'm 71and need new glasses. You can do this.

You could also try to use acetone on a q tip to get the varnish off. I've never tried that, I use a new razor blade that I break the back off and stabilize the wire against the cone, putting the blade at an angle and dragging it towards me.

 

[RTally]

Sorry, this is deeper than I’ve gone so not using the right description. Also, I don’t know how to draw an arrow but hope you can see the on the left the broken wire coming up. From what you have said (and thank you!!). I’ll try to clear off where it should be connected and see if I have enough slack to reattach? I’m old and my eyes seem to pay tricks on me when the wire is so very small — yikes

Don't worry about slack. Don't try to pull the lead to make it longer! That lead is fragile and easy to break. After all, it broke once without you touching it. Your best option is to use a wire strand to bridge the gap as a jumper. Use a strand from a piece of speaker wire.

It may be possible to burn the varnish or enamel insulation off the lead wire with your soldering iron. Touch the soldering iron to the tip of the wire where it is broken to see if the insulation starts smoking. If so, let the iron burn off the coating. Be sure to work with the lead raised from the surface or use a backing to protect the driver from the heat of the soldering iron.

I suggest using either liquid or brush-on rosin flux when soldering the jumper to bridge the gap.

I use a 4 inch magnifying glass on a gooseneck for close work. It helps me see the invisible things that I sometimes need to work on.

 

[alteclipsch]

I agree, don't try to pull any wire to get more slack, it'll break. It's nearly as old as me.

 

[swechsler]

I use a 4 inch magnifying glass on a gooseneck for close work. It helps me see the invisible things that I sometimes need to work on.

I've never done this particular type of work, but when I've had to do other delicate surgery like this, I've found that using a good quality 1080p webcam (I have a Logitech c920) on a makeshift stand facing down at the work can do wonders at enlarging. Bright lights are also helpful.