722k

Can you connect the channel 3 output of a nonDVR receiver into the antenna input of 722k and have it pick it up as if it was OTA and record that content that way?
 
Can you connect the channel 3 output of a nonDVR receiver into the antenna input of 722k and have it pick it up as if it was OTA and record that content that way?
The ViP receivers cannot handle analog channels. Even the DISH DVRs that could receive analog channels couldn't record them.
 
Can you connect the channel 3 output of a nonDVR receiver into the antenna input of 722k and have it pick it up as if it was OTA and record that content that way?
No.
You must remember that the signal is not digitized in the recorder. Only the digital data stream is recorded. Some early recorders did have ADCs to record analog, but this avoids those patents, I think. Now if we had an NTSC to ATSC converter we could play some tricks. (Note that the $40+ converters are ATSC to NTSC.)
-Ken