Yes, I got both ATSC tuners working for my Raspberry Pi 3.
I extracted the patch file for kernel 4.2.5 from Dropbox - wintv-dualhd-kernel-4.2.5-2016-08-10.patch.tar.xz
I used the instructions to apply the patch from Kernel building - Raspberry Pi DocumentationCode Display Moresudo apt-get install git bc git clone --depth 1 -b rpi-4.2.y https://github.com/raspberrypi/linux cd linux patch -p1 < ../wintv-dualhd-kernel-4.2.5-2016-08-10.patch cd linux KERNEL=kernel7 make bcm2709_defconfig make -j4 zImage modules dtbs sudo make modules_install sudo cp arch/arm/boot/dts/*.dtb /boot/ sudo cp arch/arm/boot/dts/overlays/*.dtb* /boot/overlays/ sudo cp arch/arm/boot/dts/overlays/README /boot/overlays/ sudo scripts/mkknlimg arch/arm/boot/zImage /boot/kernel7.img
After rebooting with the patched kernel, the two ATSC tuners appeared.
Thanks leading_edjge. Now that I know it's been done, I'll have to dig in and learn how to patch the kernel. cheers.