I'm working on a model 89 code 123 and the bandswitch is very tight. I've sprayed it with contact cleaner and WD40. I can barely turn it. I don't want to break it. Is there any secret to loosening these up?
My first thought is some type of penetrating oil where the shaft travels through the mounting screw for the switch. WD40 would be my first choice as well. If this doesn't work, I would remove the switch and carefully disassemble it to see what is inside. Perhaps its just gunked up on the inside.
That's a good idea Eric. It only has a few wires going to it, so removing it shouldn't be too tough. I wonder if they are difficult to disassemble?
I agree, the lock up is no doubt on the shaft and not the wafers. I had one that I couldn't turn with vice grips on it. A squirt of PBblaster penetrating oil and wrapping the shaft with a damp paper towel and hitting the threaded area with a propane torch on a fine flame to warm it and it started to move. Repeated several times and it was free. Repeated heat on the bearing area while keeping the shaft relatively cool and the penetration oil did its job.
Good luck and don't burn down the house.
Jerry
Thanks Jerry.. I'll try the flame tomorrow. I'll let you know how it turns out. If you see a Model 89 Cabinet for sale, you'll know it went bad...lol
The heat trick sounds like it is worth trying before disassembly. Be careful what type of lube you use, some of them are pretty flammable and you don't want have them flash on you with a torch.
As for disassembly, there are usually metal tabs on the back of the pot/switch that will hold the metal casing closed. You can usually use a small screwdriver or needle nose pliers to gently straighten them out and open the back of the case. I've done this on a few other electronic devices with good success.
You sure have been doing your part to bestow the world with nice radios lately! After work, kids, dinner, and more work, I'm lucky to get an hour in the evening to work on things, so my projects progress much more slowly!
I would use a large soldering iron rather than a flame.
Steve
Somehow I think "Liquid wrench" being a penetrating grease will do the job even without the torch.
My Zenith tuning shaft was very stuck. Did not take long, dissolved the gunk and lubricated it.
It's been close to two years, still runs smooth.
Ok, change of plans.. I'll go with
Liquid Wrench... if that doesnt work
Soldering Iron heat...
Maybe flame..
in that order..
Thanks Eric.. My kids are grown, and my work consists of about 6 hours a day on the cell phone. I'm lucky in that respect because it gives me plenty of opportunity to spend time looking for radios and fixing them up.
Liquid Wrench did the trick!
It turns so easy now, I might need to tighten it up..
Yeah, lithium plus kerosene works wonders. On all things stuck and on some mentally ill.
Glad to hear it worked! Liquid wrench is what I had in mind, I just couldn't remember the name of it...
Although those old pots are of better quality than newer ones, those "tabs" will only allow a couple of unbendings before they break off. Glad to hear the fluid worked for you.
Exactly - those tabs provide limited access before they allow permanent access... Once is good, repeated use will certainly cause breakage.
Aye A little spare deoxit on the contacts is called for for the next few decades.