I added a banana jack for ground to my Cocoquantus to more easily ground it to the modular. I connect together the grounds of the power supplies in my six 5U modular cabinets. The two portable cabinets each have a dual banana jack for loop-through ground, and that’s where I connect the Cocoquantus ground. I don’t need to patch the 1/4″ inputs or outputs of the cocoquantus to carry the ground, when I only want to use the quantussy oscillators. Here’s a photo of the inside wiring.
The important thing is to connect the ground to the ground wire on the power jack that goes to the board, NOT the one that goes to the battery. When the power connector plugs in it disconnects the battery ground from the board ground.
The clip and the battery connector are standard Radio Shack parts. When adding a battery clip, the connector has to be replaced with one having the wires coming out the short side, rather than the long side, so that the clip lines up with the battery terminals. I drilled a small hole for the battery clip and fastened it with a machine screw and nut. Here’s a photo of the same mod for Tetrazzi.
For Tetrazzi, which I play more often with the battery, I also added a dummy power connector on a tether to act as the power switch. Removing the connector enables the battery and turns on the Tetrazzi.