Transmit a signal using RF transmitter/reciever without using microcontrol or a decoder/encoder
Would that be possible for the transmitter to transmit such data and
  for the receive to interpret it as a 1 or an on signal?


If you want a somewhat reliable system you cannot just send a high or a low voltage and expect that to be adequately decoded with any measure of reliability.

Think about the receiver - it's very sensitive (by design) so, in the absence of a proper signal, it's trying to demodulate spectral noise and producing basically garbage on the output. It will have an AGC (automatic gain control) that allows it to receive and demodulate anything that ranges from a proper signal to noise.

If it receives a non-random-noise signal it backs-off the AGC to properly receive and demodulate the signal. However, that signal could be from someone else down the street opening their car doors.

If you are looking at cheap radio transmitters and receivers you have to: -


Send some form of data preamble that allows the receiver to adjust its AGC or detector to properly deal with the amplitude of the received signal.
Send an address so that the MCU looking at the received data has some idea that it is from the transmitter it wants to focus on.
Send data and this could be high or low, one bit to any number of bits
Send a checksum so that after all is received you can get even more confidence that the signal is valid