Home

Welcome to the cxadc modified driver wiki!

Summary

This is the CXADC Wiki written and maintained by Harry Munday (harry@opcomedia.com), Inside this wiki and its pages, you will find general information alongside technical guidance and notations for modifying CX Cards, and obtaining effective captures of signals with them.

Concept of CXADC

Takes the cheap and common Conexant CX2388x series of video decoder/encoder chips found on PCI/PCIe TV/Capture cards and turns them into an continuous RAW sampling SDR capture card via simple driver replacement.

This is 28.6msps with the stock crystal, but is 40msps possible on almost all cards via replacing a simple timing crystal (up to 57msps possible) or using a software genarated source such as the clockgen mod's.

Crystal Mhz = Max MSPS rate. (2x MSPS = 1Mhz of bandwidth)

These CX Chips have a testing mode called RAW16 that allows continuous raw samples to be output to file this is how they are used as an SDR alongside their wide input range ment for CVBS/Broadcast signals.

Uses Of CXADC

• FM Media Capture

• SDR Radio

• Software Ossiliscope

The driving force behind the continued development of the CXADC driver and testing/modifying of new PCIe cards is due to the VHS-Decode, LD-Decode and HiFi-Decode project's capturing raw FM signals off analogue media for full lossless archival.

Fetures and Limitations of CXADC

• 256 CX Cards per system.

• 8-bit and 16-bit sampling (10-bit ADC) modes supported

• Signal centring or DC offset control is supported.

• Linux & Rasberry Pi5 support

Limitations

Windows & MacOS support, currently, there is only a raw driver for Linux, but we hope to make a version for Windows in the near future.