I have a Zinwell WB68 multiplexer for 4 directv receivers. There is only one wire installed from the mutiplexer to the master bedroom reciever so I can only record/watch one channel at a time in that room. There is no way to add a second cable (within reason). My question is whether there is such a device, similar to a diplexer, that would combine 2 satellite signals after the multiplexer, connectied to the single line going to the bedroom, and then split into 2 satellite signals in the bedroom? If not, if I use diplexers with an OTA antenna, will I be able to record 2 channels at once (assuming one of the channels is from OTA)? Thanks!