Harbinger One: R54 change

[madbean]

This was added to the build document for the Harbinger One.

04.19 Revision: Some reports of problems with excessive voltage drop using R54. If using the filter PCB, you should jumper this resistor, or replace it with a 1N5817. If replacing it with a 1N5817, omit D1. The 1N5817 should be oriented with the anode on the left and cathode (banded side) on the right.