Amateur Radio has a history of re-purposing Radio & Electronics surplus, for a variety of uses (receiving, transmitting, accessories, etc.).
Recent posting on Github the past two weeks https://github.com/stdw/cm-sdr
“cm-sdr” is a piece of software to turn a Broadcom BCM3383-based cable modem into a general purpose Software Defined Radio (SDR)
In its current state, cm-sdr serves as a proof of concept. It can currently stream I/Q data to a peer via TCP. A script to demodulate and play FM radio broadcasts is also provided.
cm-sdr is dependent on many functions and memory mapped registers in the unmodified firmware. Thus, at the moment it is highly tailored to one specific cable modem model and firmware version.
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Earlier work by OpenWrt with the Broadcom’s BCM33xx chipset. https://openwrt.org/docs/techref/hardware/soc/soc.broadcom.bcm33xx
The BCM3383 DOCSIS 3.0 cable gateway System on a Chip (SoC) combines Broadcom's Full-Band Capture (FBC), dual-band concurrent Wi-Fi and a custom applications processor. https://www.broadcom.com/products/broadband/cable/modems/bcm3383 Current Broadcom cable modem SoC offerings https://www.broadcom.com/products/broadband/cable/modems
== greg, w9gb