Bypass OLED boost circuit

[kamocat]

The OLED boards have a switched capacitor circuit to bump up the 3.3v to 7-9v for driving the LEDs. It may be possible to bypass this circuit and use a less noisy source. (John VA7JBE suggested this idea).

The simplest option would be two cells of the three-cell Li-poly battery pack. This would certainly eliminate noise, at the cost of unbalancing the load on the batteries. The current consumption is low enough, it might be reasonable to use a linear regulator off the 12v line. It would be 70% efficient, close enough that a switching supply wouldn't make sense.