Goal:Small, easy, simple, effective, all 12v - no stray RF or dongle variations.
The Pi3 is powered off a standard 12v to USB 5v "lighter plug" charging adapter which will be replaced with a PowerWerx USB Buddy.
Having become impatient with the variation of USB dongles - just do it: W3KKC RA-35 Kit - $35
Re-packaging the BF-888 keeps the surrounding RF clean and makes the interfacing a bit more 'robust.'
Pi3 --- RA-35 --- BF-888
7805 and 2 1N4001 in Series for 3+ VDC to BF-888
White wire = Squelched audio at Vol pot via 0.1 ufd
Green wire = Mic audio via 0.1 ufd
Red wire = PTT-
Yellow wire = COS-
Shield to board common/- plane
Red and black to separated speaker
Closer look at audio and PTT points
Closer look at COS buffer - 2.2k from a COS+ point to 2N3904/2N2222 to invert
To reduce the bulk of a USB-B connector I used a short USB-A cable and soldered the -B end wires to the RA-35
