08-02-2019, 07:29 AM
Kudos on getting the rotor forks cleaned up! This shows you are determined to get this unit working right. I have seen this type of problem on many radios, including some manufactured much more recently. Did you also clean the mating surfaces of the rotor too? I expect you did. I have had a few stubborn cases where I had to put a small amount of silver paste between the rotor forks and the rotor surface they mate with in order to stop drop-outs at particular points of rotation of the tuning capacitor. I used some silver conductive heat sink compound made for CPU mounting. I applied it using an Xacto knife blade with the capacitor reassembled, carefully working the compound into the space between the forks and the rotor shaft.
Another possible trouble is when one of the capacitor vanes comes so close to the vanes it meshes with and shorts out at a particular spot. Those can be difficult to spot. Bright light and a magnifying glass can help spot the offending section and vane(s). Repeated careful moving of the vanes with the Xacto knife can usually clear the short. Watch for corrosion on the vanes. Some radios are known problem units in that regard.
Good luck!
Joe
Another possible trouble is when one of the capacitor vanes comes so close to the vanes it meshes with and shorts out at a particular spot. Those can be difficult to spot. Bright light and a magnifying glass can help spot the offending section and vane(s). Repeated careful moving of the vanes with the Xacto knife can usually clear the short. Watch for corrosion on the vanes. Some radios are known problem units in that regard.
Good luck!
Joe