Wish I had more input for ya. I do not own a 3gx. I only know stuff from the posts made on here. I am positive that some here can help you more.
Thats true what Jesse said.. I did the same. With DX6i you cant run just the specktrum satellites. You need a seventh channel for gyro gain then which you dont have.. So run like an AR6200 or similar.. Tony used his like that cause he has a DX8 .. its an 8 channel.. or eve DX7 wont need a normal satellite.. Lower than that dx6i and all 6 channel TX's need a full RX..
dont know if how it would work with just a 6 ch tx i do know the the 3g works well with the dx6ithanks for the info man. how about the AR7200BX?
you wire it like the book shows for the spektrum rx and then you have to make a jumper wire out of the white red and black lead that comes with the 3gx
you have to take the white wire out of the jumper one end will plug in to the 3gx bind port the other end i take the purple thro. wire and place it in were the wite wire was and then plug it in to the rx in the thro. port this is how it powers up the rx you bid it using the bind port on the rx not the 3gx
should look like this