The output of analogWrite is from a separate, asynchronous piece of hardware called a counter/timer.
This continually outputs pulses all the time, the call to analogWrite merely changes the width of future pulses.
It doesn't wait, it doesn't take immediate effect, and so outputing a single pulse is not feasible using analogWrite.
Trying to encode 8 bits as an RF pulse length is fraught with issues, such as the bandwidth of TX and RX, noise,
interference, AGC pumping, and probably others. Old fashioned used such schemes for analog data, and you
had to put up with some jitter and noise, but that's not a shop stopper for RC models.
Trust the people who've worked with wireless all their lives and use a packet transceiver to communicate digital/binary data. The RF12 module is cheap and there are libraries to support it. Transceivers have
checksums, packet start recognition, and other support to make data communication reasonably robust even
in such cheap ISM modules.
Anyway what is this byte?