: The external antenna jack is typically wired only for FM and Shortwave (SW). Modifications are often required to enable external antennas for Mediumwave (MW). Revision History (PCB Versions)
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
Before exploring its schematic, it's essential to understand what makes the D-808 tick. The XHDATA D-808 is an impressively versatile FM/AM/LW/SW-SSB/AIR band receiver known for its high sensitivity and multiple digital signal processing (DSP) options. Its performance, especially on the AM and FM bands, often rivals or surpasses more expensive competitors. xhdata d-808 schematic
The telescopic whip antenna routes through a protection diode network to prevent static discharge from destroying the sensitive RF inputs.
The is a highly-regarded portable digital radio known for its use of Digital Signal Processing (DSP) and high sensitivity across FM, SW, MW, LW, and AIR bands. Its internal design is centered around the Silicon Labs Si4735 DSP chip, which handles demodulation for all supported modes, including Single Sideband (SSB). Internal Architecture and Variations : The external antenna jack is typically wired
Verify supply voltage at the audio amp pin; check for DC offset at the speaker pads. I2C Pull-up Resistors
This is a premier online museum and archive for vintage and modern radio equipment. The model page for the XHData FM-AM-SW-SSB-Air D-808 (ID 305898) explicitly states, "Click on the schematic thumbnail to request the schematic as a free document.". This is likely the most direct and legitimate source for a high-quality schematic. You may need to register on the site, but the resource is invaluable for restorers and engineers. Its performance, especially on the AM and FM
While a complete official schematic for the XHDATA D-808 is notoriously difficult to find in the public domain, enthusiasts and technicians have pieced together its "story" through teardowns and reverse engineering. The radio's internal architecture is defined by its use of the Silicon Labs Si4735 DSP chip , which handles the heavy lifting for all bands. Internal Architecture
If you have opened your D-808, you might have noticed a version number on the board. The community has documented at least three major versions of the radio (released in 2018, and two variants in 2021) and two PCB versions. The original 2018 model had a white backlight, while later grey and black (SIHUADON branded) models have yellow backlighting. As for the PCBs: