Is this possible.....

[Electronic M]

Not really. Most antenna amps don't have the output power to transmit.... There's a slim chance some cable TV head end amp might be able to do that but that's going to require research.

You need a minimum of 40dBmV to do decent transmitting especially if your antennas aren't dimples tuned for the specific channel.

IIRC some people have used Blonder Tongue MCIM modulators for compact size. There's other transmitter use capable modulators made by other brands too.