Larry,
Sadly no HT's here but I am guessing some brass shim etc or tin plate screens would help. Still not convinced about the top end freq wise though with SA602. The unit wasn't that expensive so might just bite the bullet and clean the board and add the headers etc.
Linux user but that the usb bootloader is present for you at least that would seem helpful for USB programming.
If programming via ICSP I am sure the PCB had where that push button should go when programming. The normal process would be disconnect the USB and power only through the ICSP headers though?
The recent PC side software doesn't seem to have a Linux version so I guess the python scripts will be the answer but might need to figure out the connection port first. Driver?
72
Dom
M1KTA
