Thursday, May 21, 2020

Radio Shack DX-398 / Sangean ATS-909 Mods Part 4 - IF Out Mod

I am excited to share an important update with you. I will perform an IF mod to the 909. Does TP11 sound familiar? Stay tuned to this post for updates. We will use the similar location that RadioLabs used for their external FM antenna jack on the back of the receiver.

Monday, May 4, 2020

Radio Shack DX-398 / Sangean ATS-909 Mods Part 3 - Tuning Knob

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 tning 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
    Copyright Arthur Hollingsworth
  • 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
    Copyright Arthur Hollingsworth
  • Gently separate the metal case and plastic control housing
    Copyright Arthur Hollingsworth
  • Remove the copper section from the 4 plastic retaining posts
    Copyright Arthur Hollingsworth
  • Using needle nose pliers, gently flatten the notch that sticks up on one side of the ring
    Copyright Arthur Hollingsworth
  • 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
  • Resolder 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,
Jesse W9JES

Radio Shack DX-398 / Sangean ATS-909 Mods Part 2 - LED Replacement

This is one of the easiest mods you can do to a 909. Replace those dim, lime green LEDs with white ones!

All you need to do is desolder the old ones and replace them. Be sure to note polarity as seen on the PCB.






73,
Jesse W9JES

Radio Shack DX-398 / Sangean ATS-909 Mods Part 1 - Disable Mute


This radio design was sold under several brands including Radio Shack and Sangean. Radio Shack's model DX-398 and Sangean ATS-909.


Disable muting while tuning aka "chuffing"


This radio has a similar design to the ATS-818 where the PLL muting circuit is processed by the controller chip.


Steps


  • Disassemble the radio
  • Locate  CNT2
  • Find the Black Wire connected to PIN 10 and gently pry out with a small screwdriver
  • Use some heat shrink tubing and cover up the exposed pin and tuck neatly behind radio
  • Reassemble radio and enjoy!