| Item | Description | Notes | | :--- | :--- | :--- | | | S-Meter Calibration | Adjusts the signal strength bar display. S1 is usually the "hang" threshold; S9 is the high signal threshold. Requires a calibrated signal generator for accuracy. | | PO (Power Output) | RF Power Adjustment | Sets the maximum power output for High, Mid, and Low settings. Usually, you select the power level on the front panel first, then adjust the value in the service menu. | | MAX FREQ | Frequency Expansion | Sets the upper and lower frequency limits. Often used to "unlock" the radio for extended Tx/Rx ranges (e.g., 24.000 MHz – 32.000 MHz). | | SQL (Squelch) | Squelch Threshold | Sets the point where the audio mutes in the absence of a signal. | | MIC | Microphone Gain | Adjusts the modulation depth. Too high causes distortion; too low makes you sound quiet. | | BFO | Beat Frequency Oscillator | Adjusts the frequency offset for USB/LSB modes. Critical for clear SSB voice quality. | | TCXO / FREQ CAL | Frequency Calibration | Used to correct frequency drift. If your voice sounds "off-frequency" to others, this corrects the reference oscillator. | | AM CAL | AM Modulation | Sets the modulation percentage for AM mode. |
Incorrect adjustments can cause severe frequency drift, destroy your final transistors due to over-current, blow the voltage regulators, or cause your radio to transmit a distorted, splattering signal that violates spectral purity regulations.
Once you have adjusted a setting, press and hold the FUNC key or power the radio off and back on. This writes the new values to the EEPROM memory. Key Service Menu Parameters Explained
While the standard user menu allows you to change basic operational settings like key beeps, display colors, and scan modes, the (or alignment menu) is a hidden layer of software control. This menu allows technicians to calibrate the radio’s internal hardware parameters without opening the case. anytone at-5555n ii service menu
The screen will now show or a calibration parameter (e.g., rEF or PLL ). Use the CH/UP/DN knob or channel selector to scroll through parameters.
: Proper alignment of these settings usually requires a signal generator, frequency counter, and an oscilloscope to ensure the radio remains on-frequency and within legal operating specs.
Adjusts the percentage of AM modulation depth to prevent clipping or muffled audio. | Item | Description | Notes | |
Based on user reports and technicians' experience, the menu includes several critical alignment areas, often labeled with acronyms like , fr0-9 , and loC . A. Frequency Alignment (BFO and Local Oscillator)
If you are adjusting SSB PEP or FM power, keep your transmissions short. The internal heat sinks are not rated for continuous, maximum-power engineering tones. Troubleshooting Common Issues
RF power output levels across different modes (AM, FM, USB, LSB) S-meter calibration for accurate signal reporting Squelch and Automatic Squelch (ASQ) thresholds Modulation limits and microphone gain baselines How to Access the Service Menu | | PO (Power Output) | RF Power
Tom needed to tweak his Anytone AT-5555N II handheld for better performance on a local repeater. He wasn’t a radio tech, but he wanted a safe, reversible change — nothing that would void warranty or break the radio.
Adjusts the clamping level; smaller values typically equal higher modulation. ⚠️ Critical Warnings
What are you trying to fix? (e.g., low audio, off-frequency, low power)
The AnyTone AT-5555N II is a versatile and feature-rich two-way radio that offers a wide range of functionalities for both amateur and professional users. One of its advanced features is the service menu, which allows users to access and modify various settings and parameters that are not available through the standard user interface. This essay aims to provide a detailed overview of how to access and navigate the service menu of the AnyTone AT-5555N II, as well as to discuss the implications and potential uses of this feature.
: The screen will display a firmware version or a specific engineering code (such as "CLE" or "SERVICE") to signal entry.