Direct Set Tuning 105.1 = 02,05,A1,43,00,29,0E,E0

02 = STX (message start)
05 = Message length
A1 = Tuner request
43 = Direct Set Tuning
00 = FM (01 = AM)
29, 0E = Frequency
E0 = Checksum

You can use windows calculator in scientific view to get the frequency. For AM make sure Dec is selected, type in the frequency and select Hex. For FM make sure Dec is selected, type in the frequency then multiply by 100 then select Hex.

For the checksum set up windows calculator select Hex and Byte. Add the bytes together starting with message length then click Not then add 1

Joe