Instructions

Older Models

Older models, 36 channel, 3x12 switch matrix versions, have a resistor matrix consisting of 36 680ohm resistors. Removing the resistor appropriate to the channel desired, or punching out the hole in the track leading to the resistor decodes the channel.

Newer Models

Nower models have an addressing module accessable from the bottom. Shorting pin 1 of IC3 (a 4081) to ground through an external spst switch does the trick. Any potting compound can be scraped away with the help of a heat gun.