Sorry missed the questions in the photograph.
1) Off and Ground are the same. To turn the circuit off you need to ground common. This removes the audio input to the circuit, and thusly turns off the AGC. This was marked this way in part due to what is in answer 3.
2) The official Wire up instructions say that Yellow is VolHigh, That is what our documentation is based on.
3) the D designations are in that single photo as it is a clip out of the schematic. The prefix was used for clarity when reading the schematic. The image was copied from the schematic and used with out editing. Yes D_Com and Common are on the same Net.
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Tim Keller - KE2GKB
