> Fm = 300 Hz (300 baud data rate) OOPS! At 300 Baud the highest "modulation frequency" (of signal bits) that you can send is only 150 Hz. This is alternate ones and zeros. Start 10101010 Stop So, If I'm reading Carson correctly... I get 2 * (100 + 150) = 500 Looks better... 73, Steve, K9DCI