: Turn the radio completely off using the volume/power knob.
: Some newer units were reported to have a "noisy receive," where the S-meter showed a constant signal even when the air was silent. Tech-savvy owners discovered a service menu fix: by navigating to CH-52 (RFG) and adjusting the RF Gain value—typically from a default of 86 up to 105—they could "tame" the ghost signal and clear the receiver. A Cautionary Tale: The Hamfest Mystery
Older YouTube videos might show an old button sequence that no longer works on newer firmware revisions. If your radio has the latest software (usually found in units built after mid-2024), here is the procedure: anytone at5555n ii service menu updated
💡 Always use a high-quality external SWR/Power meter when making service menu adjustments. The internal meter is a good guide but rarely accurate enough for precise alignment. Share public link
The service menu translates analog hardware adjustments into digital values. While the exact shorthand names can vary slightly by firmware batch, the updated menu covers these core alignment blocks: 1. Frequency Calibration (REF_FRQ / CLK) : Turn the radio completely off using the volume/power knob
Here are a few key parameters that users commonly adjust:
Typically set for roughly 12 to 15 watts of carrier power, leaving adequate headroom for audio modulation swing. 3. FM Power Calibration (FM-PWR) Menu Label: FM-P or FPW Purpose: Sets the continuous power output for the FM mode. A Cautionary Tale: The Hamfest Mystery Older YouTube
Never transmit into an open air antenna while adjusting service menus. Use a high-quality 50-ohm dummy load to prevent RF feedback from skewing test results.