Re-threading tuner

V

Vintage999

Active Member
I have a Kenwood 60-30 receiver that lost its thread in the tuner section. Found a totally roached 6030 and bought it just for the intact thread it had. Putting the new tuning thread into my original unit has proved very difficult.

Any suggestions for re-threading an old tuner? Maybe a trick or two?

Good listening...
 
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Go to HiFi Engine and get the Service Manual. Study the diagram of the string routing. Paying attention to any loops or direction and then replace. I use dial string but others swear the dental floss will work. It intending on using the donor string it will need to be untied somehow.




Barney
 
I feel your pain. I once bought a Scott 337 in a box, many pieces and yes, the dial unstrung. I studied the routing of some other analog tuners and found there is a logic to them. I laid out the pulley placement on paper and tried many different paths before finally seeing how it would work. And, that's just a start. If you can get the routing from a manual, you have a leg up. The actual work is a bit painstaking but stay at it. I don't want to say how long it took, but the results were worth it. I know, not much help but you do have a rooting section here.
 
I did this recently on a small console receiver - it took some doing but I got it -
I followed the service manual's dial cord stringing diagram -
I used 20 lb test dacron fly line backing - which was quite a bit thinner than the original dacron line -

what I found helped was using the broken string to get a close estimate of how long the string needs to be - I made the replacement about an inch longer -
I started by tying a loop - then measured out the length estimated from the old string -- you need to give yourself a little more length to account for the 2nd loop end --

It took me several trials and errors before I got my length right -- ie: too long, not long enough, loops too big - it's a goldilocks operation --

To get my non slip loops on each end of the string I tied a simple loop/overhand knot/granny knot -

I connected the first loop on the wheel and found that I needed to make 2 complete revolutions around the wheel before continuing out through the pullies --

at the tuning knob, I experimented with differing numbers of loops -- it is at this point where you can give and take small lengths to get the cord to the right length when the end loop fastens into the spring clip on the tuning wheel --

so for example, if I went with 4 loops on the tuning knob, continued through the remaining pullies and got to the tuning wheel and found I had way too much string, I went back and tried 8 loops around the knob --

the hardest part was extending that springy catch back far enough that the end loop connects to -- I used a small straight screwdriver blade to bend it back far enough and then my able assistant (my daughter) slipped the loop over the spring wire -- it's easier with 2 pairs of hands --
 

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Thanks for the moral support as well as superb suggestions by all above. I've sorted out the proper string path, got close a couple of times thought I had it perfect, then the string wrapped around the tuner knob slipped... turning the knob did not advance the string in either direction....aarrrrghhhhh.

I'm going to get away from it for a day or two - come back with fresh eyes.

Good listening...
 
Be sure all the pulleys are clean and grease-free. I find 0.9 mm window blind cord is a near perfect match for many dial cords. There's usually a spring on the large capacitor pulley that tensions the cord. It's important that the spring be in the middle of its travel so the cord remains properly tensioned over the full dial range. The manual will usually give or show the exact number of wraps to be used on the dial shaft and you should stick to it. Sometimes a bit of beeswax or similar will get an old unit going, but IMO a new setup should be spotlessly clean with no "help". I use a spot of nail polish to lock knots and often the pointer location. Naturally everything has to turn smoothly and freely. I use a bit of plastic-safe lube on pulley shafts and also clean/polish the rail where the pointer slides.
 
good idea on window blind cord --
good tip on nail polish to set the pointer --
the tension on my dial string was extremely high -- guaranteeing that everything moved when the tuner knob is turned -- kind of like it's so tight that it's not possible for it to slip --
 
Braided Dacron fishing line is what is mostly used in vintage. Dacron lasts forever and does not stretch. Any line in the 30# to 40# should suffice. It is not particularly cheap, but some fishing shops will sells selected lengths. Before restringing, apply a thin coating of Bees wax to the string. This will give the line a bit of stickyness. Stringing a tuner is an exasperating job. Good luck to you.
 
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