Brian Keith Bell

President Dwight D. CB Base Resto-Mod Part 1

🎙️ Resurrection of a Classic: President Dwight D. CB Base & Astatic D-104 TUP9 Resto-Mod!

Stoked to finally crack open my President Dwight D. CB Base Station! This rig, a decade-long resident of the garage, fired right up a few years ago and was technically working. Now it’s time for a proper restoration and revitalization to ensure this classic rig lasts!

My plan focuses on preservation, performance, and a critical deep-dive into its legendary companion, the Astatic D-104 Power Mic on the TUP9 stand.

🔎 Phase 1: Internal Inspection & Component Audit

Before replacing any parts, I need to know the radio’s precise configuration and history of modifications. This is crucial for future component sourcing and tuning.

  • Board Identification: The President Dwight D. came with two main boards. I’ll open it up to identify the Phase-Locked Loop (PLL) chip:
  • PC198AA Board: Uses the AN-858-PLA U PD858 PLL.
  • PC 407 Board: Uses the U PD2816 PLL.
  • Modifications Check: I’ll be looking for any evidence of “Super Mods,” specifically if the clarifier has been clipped or if any modulation tuning has been performed.
  • Capacitor & Resistor Inspection: I’m taking the “don’t fix it if it ain’t broke” approach with a major exception: vintage electrolytic capacitors degrade over time. I’ll be inspecting and selectively replacing these key components for long-term stability and optimal audio coupling.

🎤 Phase 2: The Astatic D-104 TUP9 Resto-Mod

The Astatic D-104 on a TUP9 base is an iconic combination that deserves the full restoration treatment.

1. Cleaning and Maintenance

  • Deep Clean: A thorough cleaning of the mic head, chrome, and the heavy TUP9 base to remove years of dust and grime.
  • Contact Cleaning: The Push-To-Talk (PTT) bar mechanism and the volume potentiometers (pots) inside the TUP9 stand will be cleaned with high-quality contact cleaner (like DeoxIT). This is essential to eliminate static, scratchy audio, and intermittent keying.

2. Cord Replacement & Wiring

  • The old microphone cord will be replaced with a new, high-quality cable.
  • Crucial Step: The new cord must be correctly wired to mate the D-104 (Audio, Ground, TX/PTT, RX) with the President Dwight D.’s mic jack (in this case a 4 pin GX16 aviation connector). Getting the pinout right is essential for it to key up and transmit audio properly!

3. Performance Upgrades (“Resto-Mod” IF required)

  • Amplifier Board Upgrade: The internal pre-amp board in the TUP9 is a common point of failure or weak performance. I may replace the vintage board with a modern, low-noise amplifier kit tailored for the TUP9 base to provide cleaner, more punchy modulation.
  • RF Filtering: D-104s are notorious for picking up stray RF (Radio Frequency) energy. I will check for and potentially install a small, simple RF suppression network (capacitor/resistor) on the audio line to keep the signal clean.

🛠️ Phase 3: Final Tune-Up & Reassembly

With the internal components secured and the D-104 revitalized, the final steps will bring the entire base station back to peak condition.

Task Detail
Pots & Switches Clean all remaining potentiometers and switches in the radio (RF gain, volume, squelch, channel selector).
Cord Replacement Replace the old, stiff power cord (not just the mic cord!) for safety and a fresh feel.
Alignment I will check the radio’s frequency and perform a basic tune-up and alignment to maximize its transmitted power and receive sensitivity, ensuring it’s right on-frequency.

Wish me luck on this fantastic project! I’ll be posting updates on the board type, any mods I find, and the transformation of this classic rig! 

You can find President Dwight D. CB Base Resto-Mod Part 2 HERE.