Apollo - Development Discussion
The original PDF version of the schematic is here: PDF rev 0 Schematic.
1) I beleive the interface is SPI rather than I2C for the TPIC595 latches.
2) 74HC14 can be used in lieu of 74HC04. The '14 has Schmitt trigger inputs, might help with noise immunity on the control line(s).
3) Suggest considering PIN diode antenna switching instead of a relay (RL15). For those who operate CW QSK, quiet is nice. It's even nice for those who don't :-) [KK7P]