I would first check really carefully...with a loupe or magnifying glass, and a STRONG light to see if the existing knob is not already split perhaps.
As far as the control itself...I would avoid spray stuff.
I'd suggest a thin oil, with a toothpick. study the control carefully, finding the bearing points. Drop one drop of oil wherever you see the point where something supports the rotation (perhaps front and rear bearing??)
Again, a strong lamp is key. Be nice to the 2C. It is an amazing, and trailblazing rig!!
...Dave? KD2E
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On 3/21/23 5:17 PM, Dave via groups.io wrote:
Gary, Dave, John,
Thanks for the replies!
I removed the knob this afternoon and it is in good shape.
It looks like the set screw presses against a fiber like bushing that surrounds the shaft and this presses against the shaft for a tight fit.
It did not feel stuck but I cannot turn it by just grabbing the shaft with my fingers.
The shaft is round without a flat spot so I guess it is just a tight compression fit that does the work.
I can move the switch to all three positions with a pair of pliers and LSB/USB works just fine !!!
I may open it up and look at the underside and then try some lubricant of some sort on the shaft, any suggestions?
I have WD40 & PB Blaster here to loosen it up some to start but maybe some kind of light oil after that?
Dave KC3AM
On 3/20/2023 9:50 PM, Gary Follett wrote:
That knob? should most certainly operate with a click at each position, allowing reception of AM, USB and LSB/CW.
There are two possibilities. One is simple, that the set screw for the knob is loose. I think this is a setscrew type knob¡
If the set screw is very tight but you still cannot get a switch action, remove the knob and have a look at the shaft. Try to turn it gently with a pliers. If you get the same result, remove the cover and have a look at the coupling between the small inner shaft and the switch behind it to see if it is loose or broken. That coupling is below the chassis (underside) towards the back, with the shaft going between the coils of the bandpass filter coils.
Try that. If no joy, I have the last possibility you. Don¡¯t want to hear unless you are really good at repair work.
Gary
W0DVN
On Mar 20, 2023, at 8:28 PM, Dave via groups.io <kc3am@...> wrote:
Hello everyone,
Last summer I picked up a 2-C to go with my 2-NT.
I have been using it for CW without any troubles.
I tried to listen to some SSB signals tonight and I found a problem...
I cannot tune in the SSB signals, the mode control just spins around and has no effect.
This is the first time I have tried to listen to SSB so this is new to me.
Looking at the schematic before I open it up it looks like the mode switch should have a few positions to it and not just spin around.
Am I correct?
Thanks much,
Dave KC3AM
