This is not required when building the bus monitor, but it is sure nice to have its help. As can be seen in the photographs, this is just a bare board with some holes. The last photo shows the jig overlaying a completed board just so you get the idea.

Since the LEDs are little and do not sit well on the board they are difficult to get them all exactly in the correct spot and facing exactly the same way. This alignment jig slips over the LEDs and allows them to be soldered in place in uniform rows and uniform spacing.

There are two parts to the jig, one for the top two rows of LEDs and one for the status LEDs on the left hand side. Note that the LEDs will need be installed before any adjacent sockets or switches that would be in the way of the jig.