Anytone At5555n Ii Service Menu Work -

AnyTone AT-5555N II service menu is an undocumented feature primarily used for fine-tuning frequency alignment and modulation. While users report it is effective for resolving specific issues like "S7 noise" on the S-meter, it is generally considered complex and carries a risk of misaligning the radio if not done carefully. Google Groups Service Menu Performance & User Feedback Audio Modulation Improvements

: Users have successfully used the service menu (specifically the

setting) to increase modulation levels from the factory default of 31 up to 63 for "full audio". Addressing S-Meter Noise

: A common complaint for newer units is a high base noise floor (S5-S7) even with no signal. Adjusting the

(RF Gain) setting in the service menu (typically around value 105) has been noted as a working fix by some operators. Precision Alignment

: The menu allows for individual alignment of the local oscillator ( ) and beat frequency (

) for different modes (FM, USB, LSB). Experienced users recommend adjusting first to get as close as possible before tweaking for final steps to preserve other mode settings. Google Groups How to Access the Service Menu

Accessing this menu requires a specific sequence that is not found in the standard manual. Preparation anytone at5555n ii service menu work

: Turn the radio off. Ensure all switches are in the upper position except for NB/ANL, which should be set to Activation : Press and hold both the buttons simultaneously while turning the radio on.

: Release the buttons and quickly press the following keys in order: RB, NB, SCAN, MEM, EMG Navigation Channel Selector to scroll through menu items (e.g., CH-52 for RFG). Key the to view the stored value and hold while rotating the VFO to change it. Service Menu vs. Standard Background Menu For most common adjustments, the standard Background Function Menu is safer and more accessible. Bob's CB Radio : Long press [MENU] for 2 seconds. Common Settings : Configure (levels 1-36), SWR Protection SSB Clarifier Bob's CB Radio

There is no official documentation for service menu settings. It is highly recommended to record original values

before making any changes, as a factory reset may not restore these specific internal alignments.

of known setting codes for frequency alignment or instructions for the PC programming software Anytone 5555n Ii Service Menu - Google Groups 24 Jul 2024 —

This guide focuses on the "Engineer" service menu, which offers granular control over RF performance, far beyond the standard user settings.

Accessing the Engineering Mode

Before proceeding, understand that these settings alter the fundamental operation of your transceiver. Write down your default values before changing anything. AnyTone AT-5555N II service menu is an undocumented

To enter the Service Menu:

1. Turn the radio OFF.
2. Press and hold the FUNC button.
3. While holding FUNC, turn the radio ON.
4. Release the FUNC button. The display will show a code (usually ending in -- or a number).

Once inside, rotating the Channel Selector navigates through the parameter columns, and the UP/DOWN buttons (or sometimes the VR knob depending on firmware) adjust the values.

Part 1: Why Do You Need the Service Menu?

Before touching the buttons, you must understand why the service menu exists. The AT-5555N II is calibrated at the factory using automated equipment. However, shipping vibrations, temperature changes, or component aging can shift these values.

Common symptoms requiring service menu work include:

• Frequency error: Listening on Channel 20 (27.205 MHz) but your clarifier shows you are 50 Hz off.
• Low deadkey: Your amplifier requires a 2-watt DK, but the radio only outputs 0.5 watts.
• Modulation distortion: Your AM audio sounds "crunchy" or SSB audio lacks punch.
• Receive sensitivity: Stations that used to be S-9 are now S-5.

The Service Menu allows you to adjust these hardware parameters without soldering iron or trimmer capacitors.

Critical Warning: Entering the service menu and changing values incorrectly can render your radio deaf, silent, or completely inoperable. Work slowly. Document original values before changing anything.

Inside the Chip: A Deep Dive into the AnyTone AT-5555N II Service Menu

The AnyTone AT-5555N II is regarded by many as the last "real" CB radio. While its front-facing user interface offers a basic menu, the true capability of the radio lies hidden behind a key combination known to technicians but rarely explored by the average operator. Turn the radio OFF

Welcome to the Service Menu. This is where the hardware meets the software, and where you can tune your rig from a "stock radio" into a precision communication device.

Accessing the Service Menu

Entering the service menu on the AT-5555N II is not a simple button press. It requires a deliberate sequence, a holdover from the radio's lineage (originating from the Qixiang/AnyTone design family). To access it:

1. Turn the radio off.
2. Press and hold the FUNC (Function) button and the A/B button (band selector) simultaneously.
3. While holding both, turn the power on.

Upon successful entry, the radio will boot to a blank or diagnostic screen, often displaying a version number (e.g., V2.0 or V3.0) and then entering a mode where the main VFO displays hexadecimal or numerical values. You will know you are inside because standard channel-changing buttons now adjust internal parameters like PLL reference oscillators, S-meter gain, and power amplifier bias.

Scenario C: Low Receive Volume or Dead S-Meter

The Problem: Local stations are S-9 on your friend’s radio, but S-3 on yours. The audio is quiet.

The Work:

1. Enter Service Menu -> P-15 (S-Meter Zero).
2. Remove the antenna. Connect a dummy load. The meter should read "0."
3. If it reads "1" or "2", adjust P-15 down until it reads zero.
4. Next, inject a known signal (e.g., an RF signal generator set to S-9 at -73dBm).
5. Navigate to P-16 (S-Meter Full). Adjust so the meter reads exactly S-9.
6. For audio volume, check P-58 (Mic Preamp) on receive? No – that’s for TX. For receive audio gain, check P-50 (AF Gain threshold). Increase this carefully to avoid hissing.

Should You Do This Yourself?

Honestly? Only if you have the gear.

If you don't own a frequency counter or a Bird wattmeter, do not open the service menu. Instead, send the radio to a reputable tech. The cost of calibration ($50-$80) is far less than the cost of a new AT-5555N II ($300+).

However, if you are a ham with a bench, the service menu turns the AT-5555N II from a "good off-the-shelf radio" into a precision instrument.