BC780 Volume/Squelch knobs sticking

[kb5udf]

Hi all,

I have a trusty bc780 that had been gathering dust, and decided to repurpose as a dedicated aviation scanner.
Problem is the concentric volume and squelch knobs are sticky. Rotating one, often rotates the other unless I physically
hold onto them. Neither rotates very smoothy and seems to require more force than it should. Any ideas?

Thanks in advance

 

[iMONITOR]

Hi all,

I have a trusty bc780 that had been gathering dust, and decided to repurpose as a dedicated aviation scanner.
Problem is the concentric volume and squelch knobs are sticky. Rotating one, often rotates the other unless I physically
hold onto them. Neither rotates very smoothy and seems to require more force than it should. Any ideas?

Thanks in advance

Carefully give a little squirt of electrical contact cleaner between and behind the knobs. Let it soak awhile, then gently pull the knobs straight out and they should come off. Do NOT use pliers, or pry with a screwdriver as the knobs become very brittle and will likely break. Once removed, give the brass shafts another squirt of cleaner, wipe off excess and replace the knobs. Problem solved!

 

[cg]

I have found that the two knobs can press together, often because the squelch one pulls out slightly. You can try to press just the outer squelch ring back or gently pull out the volume. But as was mentioned, the knobs have a history of breaking and care needs to be exercised (I no longer have to worry about them binding on two of the 780s because they no longer have volume knobs).

chris

 

[Ubbe]

It's probably just some old dirt between the plastics that have hardened. The plastic controls on old 780's are very brittle so I advice against trying to pull them off. Spray with some lubrication, perhaps silicon spray or lubricating contact cleaner, but first read the instructions that it is safe to use on plastic.

/Ubbe