405 lines from Raspberry Pi 5

[Mike Watterson]

Also the QFN20 package seems to have a direct subcarrier "AUXIN", intended either for Nicam or a second sound carrier (zwei), so a direct 3.5 MHz from a simple AM osc could feed there.

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At power on with no I2C signalling and 4MHz crystal the defaults are
Negative Video
FM Sound on 5.5 MHz offset
UHF mode and 591.25 MHz (Ch E36)
Sound PLL reference 31.25 kHz (Fext / 128)
Picture-to-sound ratio is 12 dB
Peak White clip on
Test signals off
GPIO pin = 0V