Anytone At5555n Ii Service Menu Updated Fixed

Guide: Accessing the Updated Service Menu on the AnyTone AT-5555N II

Subject: Service Menu Alignment and Hidden Features for the AT-5555N II Series

The AnyTone AT-5555N II (and its various brand variants like the CRT Megapro) is a popular choice for 10-meter radio enthusiasts. While the standard user menu allows for basic adjustments, the Service Menu (Alignment Mode) provides access to critical calibration settings for RF power, squelch, and frequency offset.

Due to recent firmware updates, the method to access this menu has evolved. This guide outlines the current procedures and the settings available.

Critical Parameters to Know (Updated List)

Note: These addresses are for the N II model only, not the original 5555N.

| Parameter | Function | Typical Value (AM) | Note | | :--- | :--- | :--- | :--- | | P-07 | AM Carrier Power | 25-35 | Lower for amps | | P-09 | SSB ALC Max | 85-95 | Don't max this out | | P-14 | Frequency Fine Tune | 500-520 | Center = 512 | | P-22 | S-Meter Zero (Squelch) | 15-25 | Adjust until S-meter reads 0 | | P-41 | TX Audio Limiter | 60-80 | Higher = Louder | anytone at5555n ii service menu updated

Disclaimer: These are starting points. Every radio is different due to component tolerances.

⚠️ Important Safety & Legal Notice

The service menu (also called "hidden menu" or "alignment mode") of the AnyTone AT-5555N II is not intended for end users. Entering this menu and changing values can:

• Permanently damage your radio (e.g., corrupt EEPROM, desensitize receiver, distort transmit)
• Void your warranty
• Violate FCC/regulatory compliance if misaligned
• Cause harmful interference or off-frequency operation

Only experienced technicians with proper test equipment (frequency counter, oscilloscope, power meter, modulation analyzer) should access service mode.

Common Service Menu Entry (For Reference Only)

For most AT-5555N II units (pre-2024 firmware): Guide: Accessing the Updated Service Menu on the

1. Turn radio OFF
2. Press and hold FUNC + BAND
3. Turn power ON while holding both
4. Release after display shows "SEL" or "TEST"
5. Use CH UP/DN to navigate parameters (e.g., PLL reference, TX power per band, S-meter, ALC, deviation)

On some newer units, the key combo changed to FUNC + MODE or requires a specific button sequence after boot.

Exiting & Saving

To ensure your hard work isn't lost:

1. Press and hold the POWER button for 2 seconds.
2. The radio will beep three times and restart.
3. Important: Cycle the power off/one once more after exiting to reset the VCO logic.

PLL Unlock Reset

If the radio displays "------" or random numbers, the PLL has lost lock.

1. Enter Service Menu (Method A).
2. Locate the PLL Reference menu (often tied to the Frequency Tolerance menu).
3. Adjust the voltage until the radio locks to a known frequency. If this fails, the VCO (Voltage Controlled Oscillator) may be physically misaligned (requires opening the chassis and adjusting the VCO coil).

Service Menu Parameters Explained

The following parameters are typically accessible in the updated service menu. Note that not all versions display every option. Critical Parameters to Know (Updated List) Note: These

| Parameter | Description | Notes | | :--- | :--- | :--- | | SQUELCH | Sets the threshold for the squelch potentiometer. | Usually calibrated so the outer knob positions correspond to tight and loose settings. | | RF POWER | Adjusts the High and Low power output levels. | Critical: Do not exceed the radio's design limits (typically 25W-40W depending on the model). Overdriving reduces lifespan. | | FM DEVIATION | Sets the modulation width. | Critical for clear audio. Too

Since you requested a "full paper" style breakdown regarding the updated service menu for the Anytone AT-5555N II (and its variants like the CRT SS 7900 or Maverick MC-7900), I have compiled a comprehensive technical guide below.

This document details the updated service menu access, parameter definitions, and the critical engineering differences between the "Old" and "New" PCB versions that often necessitate these menu changes.

How to Enter the AnyTone AT5555N II Service Menu (Updated Method)

For radios with firmware V2.0 and above, the entry sequence has changed to prevent accidental access.

Step-by-Step:

1. Turn the radio OFF.
2. Disconnect any microphone (this is critical for some models to prevent shorting).
3. Press and hold the BAND button and the INFO button simultaneously.
4. While holding both buttons, turn the power ON.
5. Continue holding until you see "SER" flash on the LCD, followed by a numerical value (usually "01" or "1").
6. Release the buttons. You are now in the Service Menu.

Note: If the radio boots normally, you missed the timing. Power off and try again.