Separate 144MHz receiver input for the IC-746
1. Remove the top and bottom covers from the IC-746
2. Mount 2 x N type connectors on a small plate on the back of the rig. You will need to space the panel away from the rig, I used extra nuts. There is no need to drill any holes, the plate can be mounted using the existing ventilation slots. One N socket will become your external receiver input and the other will allow you to loop the antenna back into the IC-746 so you can use it normally if you wish.
3. With the rig upside down with the front panel facing toward you. At back-left there is a square metal screening plate held in place by four screws - remove it.
4. Unplug the coax connector labelled J121 VRX and carefully pull it through the top side of the rig. You will see it goes to J601 on the PA board. Remove the TMP connector and solder the cable to one of the N connectors. This is your RX loop from the rig.
5. Make a new coaxial cable terminated with a TMP connector, plug it into J121 VRX and solder the end to the second N socket. This is your external receiver input.
6. Job done! Screw the covers back on the rig.
I have also changed the IC-746 Molex power connector to Powerpoles.