Since today is the first time I opened up my sbitx box, all kinds of possibilities popped into my head.
For instance I have a Pi 5 on order and I just got the shipping notice. You can buy GPIO extenders and suitable standoffs to mount it and its fan upside-down with some room for airflow. So IMO there probably is a way to fit a Pi 5 into the box mechanically, and with the fan running and perhaps more aggressive CPU throttling and/or fan speeds it probably would be okay in terms of heat. The end plate would need to be modified or replaced because the external USB and Ethernet would now be in a different place. Same could be said for the hatch on the top of the case, it would be in the wrong place. May or may not be an issue depending on what you want to connect to the radio.
As for power, in the worst case the Pi 5 wants 25 watts so 5 amps at 5 volts. It also needs a compatible USB-C implementation that will convince it that it is getting that 5A. If not it falls back to 15 watt / 3A mode to be backwards compatible with older Pis. In the fall back mode it still works, but it does not supply much power to the external USB devices. You can run things like keyboards and mice, but not SSDs/NVMe/etc, they draw too much power. However you can still use them with a powered hub if that use case is important to you.
So, if all of the above is correct, a Pi 5 could work inside the sbitx case. It is said to deliver 2x or more improvement on performance.
Feel free to poke holes into this theory!
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Regards,
Dave, N1AI
Dave, N1AI