Tom Granger's Sony FX-300 "Jackal" Upgrade Turns a 1978 Hi-Fi Portable Into a Teensy-Powered Marvel
Engineer Tom Granger has taken an unusual 1970s-era Sony multi-functional portable TV, the FX-300 "Jackal", and given it a serious upgrade — complete with Bluetooth and FM radios, a working microphone, and a 3.2" TFT display.
"The Sony FX-300 (aka "Jackal" in [Japan]) caught my eye in late 2019," Granger explains of the project. "A 1978 technological wonder combining a miniature B&W TV, cassette recorder with microphone and AM/FM radio all in a compact, portable design that aged really well and was oozing cyberpunk."
An analog TV, however, isn't of that much use today. Having picked up two non-functional units from Japan — one of the two countries, alongside the US, in which the Jackal was released — Granger set about creating a single functional Jackal with some more modern features.
"The core of the project is this pyramid made of Paul Stoffregen's incredible Teensy 4.0 microcontroller (600MHz!?!), stacked on its dedicated audio board, resting itself on a protoboard with a bunch of terminal blocks," Granger explains. "I wanted everything to be removable."
"Getting the FM module to work was the trickiest bit. I accidentally destroyed the SI4703 which I ended up replacing with a RDA5807M (cheap!). Both are using I2S. I had trouble making it work until I physically separated the data and clock wire. I'm still working on the code."
The finished unit is a work of art, with the CRT having been replaced with a 3.2" color TFT which serves as a visualization element for music played over Bluetooth or FM radio.
As many of the original buttons and sliders as possible are made usable, and even the VU meter works — using a clever trick to read capacitance using one analog and one digital pin on the Teensy, driven by some software trickery, then using a pulse-width modulated (PWM) output to drive the original VU meter panel.
Full details of the impressive build can be found on Granger's Twitter thread, though he notes that the software side of things is still a work-in-progress.