Rebuilding a Central Electronics 100/200V VFO

If you own one of the wonderful CE 100V or 200V transmitters chances are good that the main
tuning is rough and "lumpy." This is most likely the result of bad bearings within the VFO assembly.
This is a pictorial"how to" for replacing these bearings which will result is a silky smooth VFO feel.
I have assumed the VFO has been removed from the transmitter and cleaned up a bit. To do this
job you will need a variety of small tools and the following which you may not have: a small
gear puller, drill press (or other small press) and snap spring pliers. As you proceed through
the process carefully clean each part and set it aside.

Remove the dial (two set screws).
Remove the two tubes
Remove the four lamp assemblies, remove &
check the bulbs. Ensure they are #51's.

Fold back the wiring harness.
Remove the large gear assembly which is held
in place with a wire clip. Don't lose the clip! Clean carefully so both halfs "rotate."

Lage gear assembly removed. Clean the shaft.

Remove bottom cover (4 screws). One
spacer must be removed for clearance. Clean
the lead screw and use a little lithium grease.

Remove the bearing assembly (3 screws) &
carefully unscrew (CW) from the lead screw

Don't loose the spring and regular washer
that remain on the lead screw shaft.

We will be replacing the two bearings
(Fafnir S3KDD) and the preload spring.
Original spring provides excessive preload.

With a large screwdriver carefully pry up
the small brass gear away from the body.

This will allow you to now use a gear
puller to remove the gear.

Remove the internal snap ring from the
shaft end of the assembly. The preload
spring should force out the end bearing.

Push the bearing assembly out of the housing.
You will now expose the othe bearing, the
preload spring and spacer. Clean everything.
With a gear puller remove the shaft end bearing. The spring and spacer can now be
removed. Discard the spring and bearings.

With a drill press push off the other bearing.
Don't push at the shaft itself but open the jaws
so you can push on the sholder

We're ready for reassembly using the new
bearings and spring.

Push the end bearing into place using the
drill press again. Push it on as far as it
can go onto the shaft. Slip the spacer and
spring onto the shaft and set the second
bearing into place. It will slide easily onto
the shaft. Place the assembly into the housing
and while compressing the spring with the
bearing, reinsert the internal snap ring.

Press on the small brass gear. It should be
positioned so that the bottom of the gear is
at the height of the top edge of the housing.

Screw the bearing assembly (CCW) back onto the lead screw. Reinstall the lamp assembly
and harness. Install the dial, tubes and their
shields. Ready for electrical testing.

Back to Index