Alan,
Well... no, pin 11 isn't truly grounded.? Here's a funny thing which has sent me on a wild goose chase:? When my ebay special variable PSU is powered on, but in standby, it presents 10ohms between +ve & gnd. That really confused the debugging process.
I've been doing a bit more digging around, and there's 1.8v from pin 18 on the QRPLabs synth board to pin 1 of the SMD chip. It looks from the synth board instructions that pin 18 should be 3.3v, but there's no reference to pin 18 in the main board instructions.?
I'm only seeing 1.8v on pin 18 when the synth board is inserted.? If I remove it and check the pin output on the mainboard there is nothing.
Otherwise, on the synth board pins 10,9,8 have 5v.
Oh... silly, silly me.? I suspected I'd perhaps got the resistors incorrect for the LM317, but having just looked closer, the LM317 says BS170 on it, and vice versa for one of the BS170s.? *facepalm* as the youngsters say.?
