The content of V4 upgrade:

1. The receiving part of Si4732 is equipped with a shielding cover to suppress electromagnetic interference. To ensure the safety of the SI4732 DSP main control, an ESD device was added at the antenna input end.

2. Move the Hi-Z circuit to the front end of the antenna path and use a more stable VCC_RADIO power supply to maintain signal resonance and reduce noise.

3. A new function of using wired headphones as FM antennas has been added (it needs to be used in an environment with strong FM signals, and the headphone cable should be relatively long to achieve better results).

4. The left and right channels have been swapped. At the same time, readjust the parameters of the power amplifier and speakers to improve the sound quality.

5. More expensive and advanced accessories have been replaced: a more robust and durable telescopic antenna, and a more comfortable and anti-slip knob cap

Basic functions：

1. It adopts ESP32-S3 main control +SI4732 DSP, supports broadcast ALL Band, LSB USB AM FM mode, and supports AGC/ATT functions

2. It adopts a 1.9-inch IPS high-definition color screen, supporting the adjustment of screen backlight brightness and battery level display

3. It is equipped with a built-in 1W power cavity speaker, providing a loud and pleasant sound quality

4. Supports upgrading to the latest firmware. The firmware version pre-installed in the factory should be at least VER.2.3.1. Due to frequent firmware updates, please update the firmware to the latest version in a timely manner according to the manual after receiving it to maintain the latest usage experience.

5. It is equipped with an internal headphone amplification circuit, ensuring a loud and clear volume when listened to through headphones

6. Built-in Hi-Z circuit to enhance the resolution of weak signals

7. Insist on using the original ESP32 module (ESP32-S3-WROOM-1-N16R8), and do not use counterfeit modules of other cloned models.

Parameter：

- Brand: AMNVOLT

- Model (Hardware version) :V4 

- Main control: ESP-32-S3

- Working mode: FM/AM/LSB/USB (Note: Not supported for aviation bands)

- Receiving frequency band: HF/SW/MW/VHF

- Frequency range: LW, MW,SW (150kHz - 30MHz), VHF (64-108Mhz)

- Screen: 1.9 inches, 170*320 resolution

- Screen brightness: 32 to 255 levels, adjustable

- Charging interface: TYPE-C (cannot be charged with a fast charger)

- Audio interface: 3.5mm three-segment stereo

- Antenna interface: SMA-KE (inner hole)

- Battery capacity: 800ma

Shipping list：

- 1 x AMNVOLT V4 radio (ABS shell)

- Two antennas (telescopic antenna with pull rod/rotating antenna with ring)