sBitx Microphone Alternatives - drexjj/sbitx GitHub Wiki

sBitx Microphone Alternatives

The sBitX v3 ships with a stock microphone that is generally considered suboptimal for voice modes, primarily due to its low gain and hollow sound. This guide explores alternative solutions for improved audio performance.

1. Replace the Condenser Element

The primary issue with the stock microphone is its condenser element. Fortunately, it can be replaced with a higher-quality alternative.

Recommended Replacement

A good option is the AOM-5024L-HD-R electret condenser microphone. This element has a higher gain (-24 dB) and delivers improved audio clarity.

Replacement Steps

  1. Disassemble the microphone case

    • Take notes or photos of the interior before making changes.
    • Pay attention to the polarity of the existing element's wires.
    • Observe the PTT switch assembly—its spring must be correctly positioned.

  2. Remove the old microphone element

    • De-solder the old element, keeping the wire leads intact on the PCB.

  3. Install the new element

    • Solder the leads to the new microphone element, maintaining the correct polarity.

  4. Improve sound damping

    • Place some loose cotton batting or cotton balls around the microphone element to reduce resonance and improve audio quality.

  5. Reassemble the microphone

    • Ensure all components are correctly positioned before closing the case.

2. Use a USB Microphone

If you are using the sBitX Toolbox, you can take advantage of the USB Headset app in sBitx Toolbox. This allows you to use a wide range of USB-connected microphones and headsets, which can significantly improve audio quality over the stock microphone.

3. Use a Wireless Microphone

The Raspberry Pi’s built-in Bluetooth does not support Bluetooth headsets for this purpose. However, a wireless microphone or headset that uses a USB wireless receiver should work.

4. Using Other Handheld Microphones

The sBitX microphone interface uses a 3.5mm TRS (Tip-Ring-Sleeve) jack with the following pinout:

  • Tip → Mic+
  • Ring → PTT
  • Sleeve → Ground

Although TRS plugs are common, few radios use this exact configuration for mic input. You may need an adapter cable to use third-party microphones.

Compatible Hand-Mics

  • TIDRadio TD-HM060 (Requires replacing the 2.5mm TRRS plug with a 3.5mm TRS plug)
  • Baofeng-style microphones (Ensure correct wiring and replace with a 3.5mm TRS plug. It’s also recommended to disconnect the speaker element inside the mic housing.)

Wiring Diagram

Plug Base  =====|GND|=====|PTT|=====|MIC+|=>  Plug Tip

By following these alternatives, you can achieve significantly better SSB transmission quality with your sBitX.