The next part of this series covers the rotary tuning knob. The
DX-398 has a good tuning knob, but it has an unwanted feature causing it
to stop or "click" in small increments. It is hard to spin the dial
freely while tuning for DX. This is due to the plastic notches or
detents in the tuning shaft that mate up with a half-circle in the metal
retainer/spring assembly.
Arthur Hollingsworth created a video on how to perform this mod - You can view it here https://youtu.be/53VKmO8mqTc?t=1172
Steps
- Locate 6 solder pads on the circuit board near the LCD display light
- Remove the solder from the 6 pad connections
- Remove the tuning control from the board
- Gently pry up the 4 metal tabs on the back of the tuning control with a small, flat bade screwdriver. Use a pair
of needle nose pliers to remove any bends
- Gently separate the metal case and plastic control housing.
- Remove the copper section from the 4 plastic retaining posts
- Using needle nose pliers, gently flatten the notch that sticks up on one side of the ring.
- Reassemble the tuning knob in reverse order noting correct
orientation (note the "detent" is now removed, but is shown here for
reassembly reasons)
- After the control has been put back together gently flatten the 4 tabs back into place using the needle nose pliers
- Re-solder the control into place on the PCB
- Check your work and power up the radio
- You should now be able to tune much easier now
73,
JJ W9JES
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