Bronurstomp, Why even involve hardware as the ccp module inside the pic can do the work for you. Just set the period and pwm of the ccp module at 38khz. and set the ccpl value to 50 % or 0%. I have been doing this for the last 5 years in the development of the tire pressure lf transmissions at 125 khz...

Dave Purola,
N8NTA