Pushing the power limits too high will overheat the final transistors and introduce severe audio distortion (splatter). 3. Modulation and Deviation (MOD / DEV)
Often used to reduce high background noise (S5-S7) present on some units. Frequency Alignment
I can provide more targeted steps to safely or help you interpret your current menu settings. Share public link
Note: exact key sequence may vary by firmware version. If these don’t work, consult the official service manual or firmware release notes. anytone at-5555n ii service menu
Once inside, you can navigate settings using the knob. To view or change a value, press and hold the PTT (microphone key) while rotating the Channel Selector. Function & Recommended Usage Ch 16 AMHI
If you suspect you made a mistake mid-way through adjusting a value and have not saved it, simply switch the radio off via the power knob before pressing any confirmation keys to discard the changes.
Before we type a single button combination, it is crucial to understand why this menu exists. The AT-5555N II is a precision analog/digital hybrid radio. Over time, temperature changes, component aging, or minor manufacturing tolerances can cause deviations in: Pushing the power limits too high will overheat
These settings control the drive levels for the final amplification stage. : Sets the carrier power for AM and FM modes.
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.
To prevent broadcasting interference during testing. Frequency Alignment I can provide more targeted steps
This digest explains the AT-5555N II service menu: what it is, what you can access, common settings technicians change, safe procedures, and troubleshooting notes. It's written for radio users and technicians who want a focused reference without having to dig through full manuals.
The Internal Frontier: Exploring the Service Menu in Modern Radios
: Aligns the S-meter to read exactly S9 when a standard -73 dBm signal is injected into the antenna jack.
: While holding those buttons, turn the radio ON. All LCD segments will light up for approximately 2 seconds.
Power cycle the radio (turn it off and back on) to save settings. 📝 Common Service Menu Parameters