HSERout "9",DEC 3,$d,$a
Should be
HSERout ["9",DEC 3,$d,$a]

Maybe that is why you are getting the "9"???

Code:
    RCSTA = $90 ' Enable serial port & continuous receive
    TXSTA = $20 ' Enable transmit, BRGH = 0
    SPBRG = 51  ' 2400 Baud @ 8MHz, 0.17%

    DEFINE HSER_RCSTA 90h ' Enable serial port & continuous receive
    DEFINE HSER_TXSTA 20h ' Enable transmit, BRGH = 0
    DEFINE HSER_SPBRG 51  ' 2400 Baud @ 8MHz, 0.17%
    DEFINE HSER_CLROERR 1 ' Clear overflow automatically
Using DEFINE the part in BOLD is not needed.
Other than that it looks OK to me...

For the radios... What modules are you using? Did you read the stuff from Dave Houston, http://davehouston.org/ ?

There is some disagreement on the forum about the preamble/synch protocol. I think Dave's method is the way to go.