‰ NOW 40 WPM ‰ TEXT IS FROM OCTOBER 2012 QST PAGE 42‰ AS ILLUSTRATED IN FIGURE 3. SELECT THE APPROPRIATE SERIAL PORT FOR YOUR COMPUTER SETUP. SELECT THE 9600 BAUD RATE AS ILLUSTRATED IN FIGURE 4. MAKE SURE THAT YOU ALSO SET THE CAT BAUD RATE OF THE FT 817 TO 9600 BAUD. CLICK ON CAT IN THE MENU BAR AND SET THE INTERVAL FREQUENCY TO 0 FOR BOTH SSB/CW AND FM. STORE THIS SETTING FOR LATER USE. ALSO, SELECT X10 SPEED FIGURE 5. THIS SETTING MAKES THE INTERFACE MUCH MORE RESPONSIVE DURING OPERATION. UNFORTUNATELY THIS SPEED SET THE FIVE BYTE COMMAND WOULD BE 0X43 0X53 0X45 0X00 0X01. THE DECIMAL VALUES OF THE FIVE BYTE SEQUENCE WOULD BE 67 83 69 00 01. THE OTHER RELEVANT COMMANDS NEEDED TO CONTROL THE FT 817 FOR THIS PROJECT ARE TOGGLE VFO, PTT ON AND PTT OFF. LETS NOW TAKE A LOOK AT THE COMMAND SET THAT IS CONVEYED TO THE FT 817 FROM SATPC32. TABLE 3 IS A SAMPLE. NOTICE THAT THE PROGRAM COMMANDS THE TRANSCEIVER TO TOGGLE THE VFO AND THEN SENDS THE FREQUENCY. THERE ARE OTHER COMMANDS THAT SET THE OPERATING MODE. THIS IS WHY SATPC32 DOESNT PERFORM WELL WITH A SINGLE FT 817. ALL OF THESE COMMANDS ALSO COMPLICATE THE SOFTWARE FOR THE INTERFACE. THE COMMAND SET FOR AN OLDER YAESU RADIO, SUCH AS AN FT 736, IS SIMILAR TO THE COMMAND SET FOR THE FT 817, BUT IT IS ALSO SIMPLER. TABLE 4 IS A SAMPLE OF THE COMMAND SET FOR THE FT 736. IN THIS CASE, THE SATPC32 SOFTWARE ONLY SENDS THE ALTERNATING TRANSMIT AND RECEIVE FREQUENCIES AND DOES NOT SEND COMMANDS TO TOGGLE THE VFO THIS IS BECAUSE THE OLDER FT 736, AN EARLY SATELLITE CAPABLE TRANSCEIVER, WAS FULL DUPLEX CAPABLE WITH TWO INDEPENDENT VFOS AND THEREFORE DID NOT NEED TO BE TOGGLED. YOU CAN SAMPLE THE COMMANDS COMING CONSTRUCTED IN BINARY CODED DECIMAL BCD FORMAT WITH THE FIRST NIBBLE 4 BITS OF THE BYTE CONTAINING THE FIRST DECIMAL DIGIT 0 9, AND THE SECOND NIBBLE OF THE BYTE CONTAINING THE SECOND DECIMAL DIGIT. THE COMBINATION OF THE TWO NIBBLES, A BYTE, IN TURN IS CONVERTED TO A SINGLE DECIMAL VALUE FOR TRANSMISSION. WHILE THIS CAN BE INTIMIDATING FOR THE COMPUTER NOVICE, MY POINT IS TO ILLUSTRATE THAT IT WILL TAKE SOME THOUGHT AND STUDY TO UNDERSTAND THE FORMATS USED BY BOTH THE CONTROLLING SOFTWARE AND THE RADIO BEING USED. HERE IS AN EXAMPLE. LETS ASSUME THE CONTROLLING SOFTWARE IS SENDING A FREQUENCY OF 435R345 MHZ TO THE RADIO. THE FIRST TWO DECIMAL DIGITS OF THE FREQUENCY 43 ARE CONVERTED INTO BCD. THE BINARY CODE FOR 4 IS 0100. THE BINARY CODE FOR 3 IS 0011. PUTTING THE FIRST DECIMAL DIGIT INTO THE HIGH NIBBLE AND THE SECOND DECIMAL DIGIT INTO THE LOW NIBBLE CREATES THE BYTE 0100 0011 OR 0X43 HEXADECIMAL OR 67 DECIMAL 0X INDICATES HEXADECIMAL. YOU CAN USE THE SCIENTIFIC CALCULATOR THAT IS AN ACCESSORY TO WINDOWS TO CONVERT FROM ONE NUMBERING SYSTEM TO ANOTHER. I USE IT ALL THE TIME. A SAMPLE OF THE RELEVANT FT 817 COMMANDS FOR THIS PROJECT IS CONTAINED IN TABLE 2. THE COMMAND FORMAT TO SET THE FREQUENCY TO THE RADIO IS P1P2P3P401 WHERE THE P S MAKE UP THE FREQUENCY IN BCD, THE 0X01 IS THE HEXADECIMAL OPCODE TO SET THE FREQUENCY. TRANSLATING THIS INTO HEXADECIMAL ‰ END OF 40 WPM TEXT ‰ QST DE W1AW ƒ