To access the service menu on the AnyTone AT-5555N II, you must perform a specific sequence of button presses during power-on. This "hidden" menu is primarily used for alignment, such as fine-tuning the frequency or adjusting the Local Oscillator (LO) Google Groups Accessing the Service Menu the radio. Press and hold the button while turning the radio Immediately release and then press the next three buttons in quick succession:
The display should now show service parameters, typically starting with (BFO adjustment) followed by a 3-digit value. Google Groups Navigation and Key Parameters Navigation button to scroll through different settings. Mode-Specific Settings
: Alignment settings may differ depending on your current mode (AM, FM, USB, LSB, CW). Common Parameters : Adjusts the 10.24MHz Beat Frequency Oscillator (BFO).
: Controls the Local Oscillator offset. Experts recommend adjusting this
to get close to the target frequency before fine-tuning with fr0, fr4, fr5, fr9
: Used for fine-tuning specific frequency points (e.g., .00, .04, .05, .09 offsets) by adjusting varicap voltage. Google Groups Factory Reset & Band Expansion Full Reset : If needed, turn the radio on while holding until "RES" then "REND" appears. Frequency Expansion
: To unlock the radio (e.g., for 11m/CB bands), turn on while holding , then switch from using the channel knob and press to confirm. Google Groups
: Changing values in the service menu without proper test equipment (like a frequency counter or signal generator) can significantly degrade the radio's performance or cause it to operate off-frequency. Google Groups alignment values for SSB or CW modes to help center your frequency? Anytone 5555n Ii Service Menu - Google Groups
The AnyTone AT-5555N II features a powerful but undocumented Service Menu used for factory-level alignments, including power output limits and frequency fine-tuning. ⚠️ Critical Warning anytone at-5555n ii service menu
No Factory Reset: There is no "reset" for this specific menu; changes are permanent unless manually reversed.
Documentation is Mandatory: You must write down every original value for all 50+ settings before making any adjustments.
Equipment Needed: Adjustments should only be made while the radio is connected to a dummy load or a properly tuned antenna. How to Access the Service Menu
There are two primary methods reported for entering the "Hidden" or Service Menu on the version II: The "Menu+Mode" Sequence: Start with the radio OFF.
Press and hold the [MENU] and [MODE] buttons simultaneously while turning the radio ON. Release the buttons once all LCD segments appear.
Immediately press the remaining buttons on the top row in order (starting with DW, then RB, NB, SCAN, MEM, and EMG). The "FUNC" Sequence: Hold [FUNC] while powering on. Then press [RB], then [NB], then [DW] in sequence.
If successful, the screen will display "FM" (Factory Menu) or a numbered setting. Navigation and Controls
Scroll Menu: Use the Channel Selector knob to move through the numbered settings (e.g., 01 to 59). To access the service menu on the AnyTone
View Value: Key the PTT (Microphone Key) to see the current value of a selected item.
Modify Value: While holding the PTT, rotate the Channel Selector to change the numerical value. Save & Exit: Turn the radio OFF to save your new settings. Common Known Settings
While most of the 59+ settings are for internal alignment, users commonly use the following for performance tweaks: Common Usage / Tip 16 AM High Power Set the maximum "dead key" for AM high power. 17 AM Low Power
Used to lower AM dead key (e.g., to 2W) for driving external amplifiers. 19 / 20 Modulation
Controls AM modulation swing; some users report setting these to zero for higher "swing". 52 RF Gain (RFG)
Adjusting this can sometimes help with the "receive noise" common on these units. bfC / loC Frequency Alignment
Used to calibrate the BFO and local oscillator if the radio is off-frequency. Anytone 5555n Ii Service Menu - Google Groups
Here’s a detailed feature-style article on the AnyTone AT-5555N II Service Menu, written for radio enthusiasts, techs, and CB/Ham operators who want to unlock the full potential of their rig. Key Parameters Inside the Service Menu (Decoded) Here
Here is a list of the most common parameters you will find in the AT-5555N II service menu. Note: Nomenclature varies slightly between firmware versions 1.0, 1.1, and 2.0.
| Parameter Code | What It Does | Typical Adjustment Range | Technician Notes | | :--- | :--- | :--- | :--- | | POWER HI | Sets RF output power on High setting (AM/FM). | 0 - 255 (Digital to Analog Convertor value) | Do not exceed 20-25W AM carrier. Set for ~20W carrier / 80W PEP. | | POWER LO | Sets RF output power on Low setting. | 0 - 255 | Usually set for 1W to 5W for driving amplifiers. | | F-ERR (Freq Error) | Synthesizer frequency trimming (PLL reference crystal). | -300 to +300 Hz increments | This requires a frequency counter. Tune to CH20 (27.205 MHz). Set to 0 Hz offset. | | SSB BIAS | Adjusts idle current for SSB linearity. | 0 - 255 | DANGER: High voltage inside. Do not touch. Set for ~100mA idle rise. | | AM CARRIER | Adjusts the AM carrier level relative to PEP. | 0 - 255 | Standard spec: Carrier is 1/4 of PEP (~25W carrier for 100W PEP is wrong). | | MOD AM | AM Modulation depth limiter. | 0 - 255 | Increase to ~95-98% using a scope. Do not go beyond 100% (flat-topping). | | MOD FM | FM Deviation level. | 0 - 255 | Standard is ±5 kHz deviation. | | S-METER 9 | Calibrates S9 signal level (usually -73 dBm). | 0 - 255 | Requires a signal generator. | | S-METER 1 | Calibrates S1 signal level (usually -121 dBm). | 0 - 255 | Requires a signal generator. | | SQ OPEN | Squelch threshold open point. | 0 - 255 | Sets when squelch opens with no signal. | | MIC GAIN | Global microphone preamp gain. | 0 - 255 | Be careful; too high causes distortion. |
Some units ship with AM carrier set above 4W, causing over-modulation on certain amplifiers. Lowering HI-PWR to 3.5W allows headroom for clean 100% positive peaks.
The service menu (sometimes called a hidden or engineering menu) provides low-level configuration and calibration options beyond the standard user programming screens. It’s used for manufacturing calibration, repairs, hardware diagnostics, and advanced feature enabling/disabling. Accessing it can change radio behavior in ways that affect safety, compliance, or legal operation.
The service menu allows you to:
A common issue following Service Menu access is the loss of user-programmed memory channels. The Service Menu access often triggers a soft-reset of the microcontroller.
Restoration Protocol: If the radio behaves erratically after exiting the menu:
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 |