Are television transmitters designed to broadcast two or more 6Mhz channels? Do commercial broadcasters do it in practice? If so, what are the limits (2, 3, 4... channels)?
closed as off-topic by laptop2d, Nick Alexeev♦ Jan 11 '17 at 2:44
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – laptop2d, Nick Alexeev
It is not common practice due to tuning issues and loss factors with large power broadcast antenna, but a diplexor can be used to combine NTSC and DTV in some situations. A multiplexor can combine several near the same frequency but complexity factors are great and tuned baluns are complex enough for one Tx with high power.
It is always a compromise to share an antenna with power losses in the combiner.