I have a linear multicode gate opener with poor sensitivity, could be off frequency. It works but only when the transmitter is up close, the issue is not the transmitter. I can spend some time reverse engineering the pcb but hoping somebody else has already done it. I don't care about the codes, I'm interested in the rf area. It is on 300 MHz.
For what it's worth, the part number on the pcb is 221421-01D
Jim