Dial cord question

[sillyradios]

I have a stereo receiver with a tuner knob that is very hard to turn. Upon taking the receiver apart, the string is way too tight and makes audible high pitched noises when plucking it.
I cant seem to find any adjustments anywhere. Does anyone know how I could loosen it? (i will be taking pictures tomorrow)

 

[Sonytubes]

Observe how the string winds and unwinds as the knob selects from one extreme to the other. It might have a kink of string that is wound over. Also try to flatten out the wound string to try to get a looser tension. My 2 cents

 

[TConnelly]

I have messed with the dial cord on two of my tuners so far. A Nikko STA-9090 receiver and a Goldstar tuner. On both the cord is tied to a spring in the drum attached to the tuning capacitor that is supposed to tension the dial cord automatically. And on both I found the spring glued to the drum. No idea why but it must be a thing. Maybe yours is also and the cord has shrunk rather than stretched. Good luck!
Cheers………………….Todd

 

[painttoad]

not long ago i picked up an sx3900 and it had a couple issues.

1: it had at least been partially restrung and the string was looped around the tuning shaft backwards.

2: the grease in the tuning shaft had basically turned to glue making it VERY difficult to turn.

some of the pioneers i worked on have a nut on the rear of the tuning shaft assembly that you can loosen, back spin the flywheel partially, retighten the nut and it may free it up. that was not the case this time. i loosely clamped the shaft vertically in my vice and hosed it with wd40 allowing it to run inside and soak then working the mech slightly then flipped it and repeated. a few times of doing that and the shaft spins freely.

this would be a good time to lube the tuning gang as well:

How to clean a tuner (analog)

1. Vacuum out all the dust you can from the interior. Don't touch the fins on the tuning cap! 2. Blow the dust out of the fins with compressed air. Don't touch the fins. 3. If you examine the tuner cap, you will see brass contacts at each point where the shaft passes through the metal housing...

audiokarma.org

another thing, the make and model of your unit along with your pics might help. some of the pullies have a small amount of adjustment or can be twisted just the slightest amount to loosen or tighten the string a touch. they are supposed to be fairly taut

good luck and be careful with that string.

 

[gadget73]

^^ agree with this, usually its a lube problem, not an overly tight string. Too loose and it slips.

 

[Lavane]

I had an old Heathkit shortwave radio where the grease had dried out on the tuning cap shaft. It was hard to turn. I used Breakfree penetrating oil to loosen it up, then Breakfree lube after. The Breakfree lube lasts a good long time. I use it on my guns. It doesn't dry out like other lube oils.

 

[gadget73]

I often use sewing machine oil, but any oil that stays will generally do the job just fine. A lot of penetrating oils contain a large amount of solvents to help them flow, but once the solvent evaporates away there isn't much left. Sometimes what remains is just sticky goo that causes more trouble.

 

[painttoad]

I often use sewing machine oil, but any oil that stays will generally do the job just fine. A lot of penetrating oils contain a large amount of solvents to help them flow, but once the solvent evaporates away there isn't much left. Sometimes what remains is just sticky goo that causes more trouble.

yes. i totally skipped that i used turbine oil on it before i reinstalled the shaft.

thanks for the reminder

 

[avionic]

2: the grease in the tuning shaft had basically turned to glue making it VERY difficult to turn.

Yamaha CR receivers are notorious for the tuner dial green sticky stuff. Disassemble and clean up all traces of the mess with acetone. Coat shafts and bushings with a light film of white lithium grease. And she will spin like a top.

 

[painttoad]

Yamaha CR receivers are notorious for the tuner dial green sticky stuff. Disassemble and clean up all traces of the mess with acetone. Coat shafts and bushings with a light film of white lithium grease. And she will spin like a top.

with the sx3900, i did not see anyway to disassemble the assembly any further. possibly there were some press fit keepers that i was not going to trash.

 

[avionic]

Yamaha's are all the same.. I practiced on a CR620 parts unit.

 

[gadget73]

do Yamahas have a long spacer that the shaft runs through? Have seen that sort of thing on other gear and the lube in that spacer does tend to get sticky. Extra fun when its a volume pot or one with concentric shafts that cant be disassembled in any sort of reasonable manner.