Skip to content

Anytone At5555n Ii — Service Menu Work

The "loudness" war is real in the CB world. The AT-5555N II is often criticized for having "tight" audio.

The menu typically consists of several columns of numbers. Below are the most impactful parameters you will encounter and what they actually do.

The AT-5555N II has dozens of hidden parameters, but you only need to touch about 8 of them for 95% of service work. Here is the decoder ring for the most common codes.

| Parameter | Function | Typical Range | When to Adjust | | :--- | :--- | :--- | :--- | | rEF | Reference Frequency (PLL Master Clock) | 0 to 255 | Most common fix. Adjusts the master oscillator. | | PA-H | High Power AM/FM Bias | 0-255 | Sets final transistor bias for high power. | | PA-L | Low Power AM/FM Bias | 0-255 | Sets final transistor bias for low power. | | Pc-H | SSB High Power ALC Threshold | 0-255 | Limits peak envelope power on SSB. | | Pc-L | SSB Low Power ALC Threshold | 0-255 | Limits low power SSB. | | Mod | AM Modulation Depth Limit | 0-255 | Maximum AM percentage (Factory ~95%). | | S-1 through S-9 | S-Meter Calibration | Varies | Adjusts receive signal strength reading. | anytone at5555n ii service menu work

  • While holding these three buttons, power on the radio.
  • Release the buttons once the screen lights up.

    • If successful, you will not see the standard channel display immediately. Instead, you will see a numeric value (usually representing software version) and you will be in a menu mode where the main encoder changes Menu Items (P01, P02, etc.).

    Verification: Turn the "Freq/CH" knob. If the top line displays codes like P-01, P-02, up to P-65 (depending on firmware version), you are inside the Service Menu.

    If you own an Anytone AT-5555N II, you already know it is a powerhouse in the world of 10-meter and 12-meter amateur radio, as well as a favorite among freebanders. This radio is celebrated for its robust build, excellent receiver sensitivity, and the famous "N2" firmware improvements over its predecessor. The "loudness" war is real in the CB world

    However, even the best factory-produced radios have tolerances. Over time, or immediately after purchase, you might notice that your transmitted frequency is off by 50 Hz, your AM carrier is too high, or your SSB output power seems low. This is where the hidden Service Menu becomes your best friend.

    Warning: Entering the service menu and changing values without proper equipment (frequency counter, oscilloscope, RF power meter, and dummy load) can permanently detune your radio, making it unusable. Proceed with caution.

    This article explains everything you need to know about the Anytone AT-5555N II service menu work, including how to access it, navigate the parameters, and perform common calibrations. The menu typically consists of several columns of numbers

    The most common reason for entering the service menu is drifting off frequency. A fellow ham says, "You are 60 Hz low on 27.555 MHz."

    How to fix this:

    Pro Tip: Let the radio warm up for 10 minutes before doing this, as the internal temperature changes the crystal frequency.

    Entering the service menu on the AT-5555N II is not a simple button press. It requires a deliberate sequence, a holdover from the radio's lineage (originating from the Qixiang/AnyTone design family). To access it:

    Upon successful entry, the radio will boot to a blank or diagnostic screen, often displaying a version number (e.g., V2.0 or V3.0) and then entering a mode where the main VFO displays hexadecimal or numerical values. You will know you are inside because standard channel-changing buttons now adjust internal parameters like PLL reference oscillators, S-meter gain, and power amplifier bias.