Xhdata D-808 Schematic [verified] File

The new version has fewer manual adjustment points (coils and trimmers), relying more on fixed-value components to save manufacturing time.

Because the D-808 is based on the well-documented Si4735, it is a favorite for hobbyists:

The radio is powered by a single 18650 lithium-ion battery . The charging circuit typically utilizes a dedicated chip near the USB-C or Micro-USB port to manage current and prevent overcharging. xhdata d-808 schematic

The DSP architecture allows for selectable AM bandwidths (1.0, 1.8, 2.0, 2.5, 3.0, 4.0, and 6.0 kHz), which are crucial for rejecting interference on crowded bands. Detailed Circuit Breakdown

Unlike the other bands, the Air Band (118–137 MHz) often uses an analog front-end—typically a CD7358 IC for down-conversion to 10.7 MHz—which is then fed into the DSP. The new version has fewer manual adjustment points

Through specific firmware patches, the Si4735 enables Single Sideband (SSB) reception, a feature usually reserved for much larger desktop receivers.

Newer units may feature a different audio amplifier with slightly different power characteristics compared to the original high-quality model. Common Modifications The DSP architecture allows for selectable AM bandwidths (1

For the speaker output, an LM4863S or similar audio amplifier IC is used to drive the built-in 3-inch speaker. Version Differences: Original vs. New

At the heart of the D-808’s schematic is the . This "all-in-one" Digital Signal Processing (DSP) chip handles the majority of the radio's functions, including: