Once inside:
Legal warning: Check your local license limits. In the US, CB is limited to 4W AM / 12W PEP SSB.
I’ve used the service menu on my AT-5555N II to gently bring my AM carrier down to 4W (for driving an amp) and to calibrate the frequency drift after warm-up. It’s a powerful tool, but treat it like surgery—make small changes, test, and always document your original settings.
Have you been inside your AT-5555N II’s service menu? Share your experience below (without breaking FCC rules, of course).
73 and happy tuning.
Anytone AT-5555N II Go to product viewer dialog for this item.
, like many advanced radio transceivers, contains a service menu used for factory alignment and calibration. This menu is intended for use by qualified technicians using specialized test equipment such as frequency counters, power meters, and signal generators. Understanding the Service Menu
The service menu allows for the adjustment of internal parameters that are not accessible through the standard user menu. These settings typically include:
Frequency Calibration: Aligning the reference oscillator to ensure the radio transmits and receives on the correct frequency.
Power Levels: Setting the minimum and maximum output power for different modes (AM, FM, SSB).
Modulation Settings: Adjusting the modulation gain to ensure clear audio transmission within legal bandwidth limits.
S-Meter Calibration: Tuning the signal strength indicator for accuracy. Important Considerations
No Factory Reset: Most service menus do not have a "reset to default" option. Changes made are written directly to the EEPROM. If the original values are not recorded before adjustment, it can be very difficult to restore the radio to its factory state.
Regulatory Compliance: Transmitters are calibrated to meet specific legal requirements regarding frequency stability and bandwidth. Improper adjustments can cause the radio to operate outside of legal specifications, potentially causing interference with other services. anytone at-5555n ii service menu
Hardware Risks: Making incorrect adjustments to power stages or bias settings can lead to overheating and permanent hardware failure. Recommended Best Practices
For those looking to optimize or repair a radio, it is recommended to:
Consult the Official Service Manual: The manufacturer's service manual provides the exact procedures and required test conditions for alignment.
Use a Dummy Load: Any testing involving transmission should be done into a dummy load to prevent unnecessary interference and protect the final transistors.
Seek Professional Service: If a radio is off-frequency or underperforming, a professional radio shop with the correct calibration tools can ensure the device is set to peak performance safely and legally.
The AnyTone AT-5555N II is a powerful 10-meter radio, but its deepest configuration options are tucked away in a hidden service menu . While the standard background function menu
handles everyday settings like Roger Beep and Squelch levels, the service menu is where you perform critical alignments and adjust internal gain settings. How to Access the AT-5555N II Service Menu Accessing this menu requires a specific power-on sequence.
Always record your original values before making changes, as there is no "undo" button for these factory-level calibrations. Preparation : Turn the radio off. : Press and hold the buttons simultaneously.
: While holding these buttons, turn the radio on. All LCD segments will light up for roughly two seconds. Verification
: Within that 2-second window, release MENU and MODE, then quickly press these buttons in order: RB, NB, SCAN, MEM, EMG
: If successful, the radio will enter the Service Mode, often starting at a specific channel setting like CH-52 (RFG) Key Menu Settings & Operations
Once inside, you can navigate and adjust internal parameters: Navigation
: Rotate the channel switch or VFO knob to cycle through the menu items. Adjusting Values : To change a value, press and hold the PTT (Push-to-Talk) button while rotating the channel switch. Once inside: Legal warning: Check your local license
: Keying the mic allows you to check the current value for certain active settings. Common Settings CH-52 (RFG)
: Adjusts the RF Gain threshold. A common fix for high background noise (S5-S7) is tweaking this value (factory default is often around 86). Frequency Alignment : Includes settings like (BFO frequency), (local oscillator offset), and (fine-tuning limits). Google Groups Standard Menu vs. Service Menu For less intrusive changes, use the standard background menu by long-pressing the
key for 2 seconds while the radio is on. This allows for user-level adjustments like: device.report Beep/Roger Beep : Toggle sounds and frequency groups. : Total of 36 levels available. Mode Setup : Selecting between FM, AM, USB, LSB, and PA. device.report Anytone 5555n Ii Service Menu - Google Groups
To access the service menu on the Anytone AT-5555N II , use the following key sequence: the radio. Hold down the buttons simultaneously and turn the radio two seconds
of powering on, release those buttons and quickly press the following sequence in order: (Roger Beep) (Noise Blanker) (Emergency) Important Considerations Calibration Settings
: The service menu contains alignment settings specific to your individual unit. Write down all original values
before making any changes. Improper adjustments can cause permanent frequency drift or hardware issues. RF Gain Fix
: A common use for this menu is to address high "noise floor" readings (where the S-meter shows S5–S7 with no signal). Changing CH-52 (RFG) from its default (often ~86) to a higher value like has been reported to resolve this. Adjustment Method : To change a value, press and hold the PTT button while rotating the Factory Reset
: If the radio becomes unstable, you can perform a full reset by holding while powering on. Google Groups frequency alignment procedures for CW, USB, and LSB modes using this menu?
Accessing the service menu on the AnyTone AT-5555N II allows for deep-level alignment and calibration, but it should be approached with caution as there is no "factory reset" for these specific internal settings. Entering the Service Menu
To enter the hidden service menu, use the following key sequence: Turn off the radio. Hold down the [FUNC] button and turn the radio on.
Immediately press the following buttons in sequence: [RB], then [NB], then [DW]. Service Menu Navigation
Scroll Settings: Press the [FUNC] button to cycle through the different alignment parameters. 73 and happy tuning
Adjust Values: Use the channel selector knob to change the value of the selected setting.
Exit/Save: Turning the radio off usually saves the current settings, though it is highly recommended to record original values before making any changes. Common Service Menu Parameters
While documentation is sparse, users have identified several key settings typically found in this menu: bfC: Beat Frequency Oscillator (BFO) center adjustment.
fr0, fr4, fr5, fr9: Frequency alignment settings used for different modes (CW, USB, LSB) and specific offsets. loC: Local oscillator calibration. Important Precautions
No Global Reset: Standard CPU resets (holding [FUNC] + [SCAN] during power-on) only reset user-level menu settings and frequency ranges, not service menu calibrations.
Test Equipment Required: 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.
Individual Variations: Every radio is calibrated uniquely at the factory. Do not copy values from another radio, as this will likely result in poor performance or misalignment.
For those needing to recover a severely misaligned radio, some users suggest using PC-based alignment software (such as the AT-5555N II PC Program Software) which may allow for reading and saving calibration files.
If the button combination fails:
The AnyTone AT-5555N II (and its various re-branded counterparts) is a popular 10-meter amateur radio transceiver often utilized in the Citizens Band (CB) and Export markets. While the standard user interface allows for basic operational adjustments (frequency step, RF gain, squelch), the device utilizes a secondary, embedded Service Menu for hardware-level calibration.
Access to this menu is intentionally obscured by the manufacturer to prevent accidental misconfiguration by untrained users. The parameters within this menu control voltage-controlled oscillator (VCO) thresholds, reference frequencies, and RF power output levels. This paper details the methodology required to enter this diagnostic mode and provides a glossary of critical parameters necessary for successful alignment.
Note: Your stock values may vary. Write them down before changing anything!
| Menu Item | Function | Typical Adjustment | |-----------|----------|---------------------| | S-01 | PLL Reference Frequency (Coarse) | Adjust for frequency counter accuracy | | S-04 | AM Power (Low) | Sets carrier level on AM mode | | S-05 | AM Power (High) | Sets peak AM power | | S-07 | SSB Power (Low) | ALC threshold for low SSB | | S-08 | SSB Power (High) | ALC threshold for high SSB | | S-11 | FM Deviation | Sets FM modulation width | | S-20 | S-Meter Zero (No signal) | Adjust until meter reads S0 with antenna disconnected | | S-21 | S-Meter Calibration (S9) | Inject S9 signal (50µV) and adjust |