In the "wire up" section of HFsigs.com, under "alignment of the bitx40" it says to turn RV1 (PA bias) fully clockwise (off) and with an ammeter in the PA power lead (so you are measuring only the current to the PA, not the whole radio), adjust RV1 for 100 ma with PTT activated but no mic audio. After that, RV1 should not be touched. R136 which is usually about mid-point when you get your bitx40, is the only control that should be adjusted to get about 1A on the ammeter when you key the mic and talk loudly into it. This is when transmitting into a proper 50 ohm dummy load, as a poor SWR can mess up your measurements. For example, the wires to the antenna connector should be no longer than a couple of inches long, if a longer distance is needed use 50 ohm mini coax to avoid causing a poor SWR at this point.
Don't "daisy chain" grounds or power connections to different circuits. The 3 grounds and 3 power leads (from Raduino, main circuit board, and PA power) should all go to a common tie point near the DC entry point on your enclosure.
Don't allow wires to lay on top of or up against the underside of the circuit board. All wiring should be kept above, below, or to the the side of the circuit board about a half inch if possible.
