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
It supports FM (with RDS), LW, MW, and SW.
The schematic for the RF section reveals how the radio handles incoming signals before they reach the DSP: 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
When examining a schematic, it is vital to know which version you own. Around 2023, XHDATA released a "New Version" (often identified by a USB-C port) with significant internal changes: For the speaker output, an LM4863S or similar
The "original" version of the D-808 included extensive shortwave front-end filters and adjustable trimmer caps to prevent FM breakthrough. 2. Power and Control
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 schematic for the RF section reveals how
Newer units may feature a different audio amplifier with slightly different power characteristics compared to the original high-quality model. Common Modifications
The new version has fewer manual adjustment points (coils and trimmers), relying more on fixed-value components to save manufacturing time.