Report and now for something completely different part 3 in Do It Yourself Posted March 24 1 hour ago, Pars said: Per my previous question, the ZF resistor is the 1.9K resistor in the schematic and PCB? I assume so, but just wanted clarification, That's correct. R50/R51 on cfa3productionss.pdf 1 hour ago, starcat said: Guys, where can I get some more information on the implementation of the SS/ZF switching board? Appreciated all the great work you are putting in. There is none but you can do it like I did and use relays to short/open the positions.