The only safe way to do this is using the "data transmission direct" option. (section 5.5 of manual) The only problem is that this eats batteries. We have made a wiring harness that works real well for this application. The data comes from the PC serial port (pin 3 signal, pin 5 grd, DB9) The data enters the TED TX on pin 6 of the DIN. Pin 2 and 3 are jumped together to force continous data transmission. Pin 4 and 3 are then "y" to a NLG13 power supply. This way the TED is powered by AC, the data is input and it is all done cleanly at the DIN plug. The data outputs from the RX receiver on Pin 6 of the DIN. Pin 4 is connected to the GAZ 12v + power and Pin 3 is ground. The GAZ end of the cable uses the 4 pole Amphenol connector. This way the RX is powered by the GAZ. Both the TX and RX have the rotary dial furthest from the metal bar (12 in manual) set to position 6. You can then jump the signal for a local GAZ out of the TX transmitter. Yellow banana for signal, black for ground. Set up the wireless first and get it tested. Then introduce the local display. The LED lamps on the TX and RX should remain solid green while this setting is used.