MO-RXLC-A is an ASK receiver module.
The MO-RXLC-Ais based on a single-conversion ,super-regeneration receiver architecture
It also has AGC, if no signal is present the gain will rise to its highest level.
In this condition it will switch high to low at random intervals due to input noise.
A CRO connected to the data line looks like 433.92 is full of transmissions.
Any ASK transmission method must first sent a capture signal of 101010........
When the receiver has adjusted its AGC to the required level for the transmisssion
the actual data transmission can occur.
50/50 1/0 must be maintained throughout the transmission.
VirtualWire looks after all this for us.