A construction article starting on page 37 of the June 2015 issue of Model Aviation tells how to build my U/Tronics Control units.  Actually it only covers the Single Channel unit.  Go to www.ModelAviation.com and select "Features" to read or download the instructions for building the Multi Channel Encoder and Decoder units.
Clancy

One small correction:
The text for the Decoder says to cut paths at 33 places, it should say 32 places which matches the drawings.
Clancy