‰ NOW 40 WPM ‰ ENGINEERING, AN MBA, AND AN MD. RONS HAM RADIO INTERESTS ARE IN SATELLITES AND RTTY, AND HE USUALLY PARTICIPATES IN FIELD DAY. HE IS AN INTERNAL MEDICINE PHYSICIAN FOR HIS LOCAL HEALTH DEPARTMENT AND HAS SPENT MOST OF HIS CAREER AS A BIOMEDICAL ENGINEER IN THE DEVELOPMENT OF MEDICAL DEVICES. RON CAN BE REACHED AT RSLISIECKI GMAIL. COM. FIGURE 3 MAIN CIRCUIT BOARD, MEZZANINE, RF FILTER BOARD, AND BATTERY OF THE REMOTE RF LEVEL ANNUNIC IATOR. WIRE WRAP AND POINT TO POINT WIR DEVICE TEST THE DEVICE SHOWN IN FIGURE 3 WAS CONSTRUCTED AND ITS MICROCOMPUTER PROGRAMMED, AND A 146 MHZ MEZZANINE RF FILTER BOARD WAS INSTALLED. WITH THE DEVICE TURNED ON, AND WITH NO ANTENNA ATTACHED TO THE RF INPUT CONNECTOR, THE ANALOG DBM METER READS ABOUT 0R3 V, CORRESPONDING TO A BACKGROUND LEVEL OF 72 DBM. R7 AND R8 WERE ADJUSTED SO THAT THE METER READING CORRESPONDS TO THE ACTUAL VOLTAGE MEASURED OUT OF PIN 4 OF THE AD8307. A POWER LEVEL OF 72 DBM IS ABOUT THE LOWER LIMIT OF RF DETECTION BY THE AD8307 LOG AMPLIFIER. THE DEVICE TICKS AND THE LED BLINKS EVERY SECOND. OTHER USES CONSIDER ADDING A SUBSYSTEM LIKE THE REMOTE RF LEVEL ANNUNCIATOR TO YOUR CURRENT REPEATER IN ORDER TO SEND THE SIGNAL STRENGTH OF A RECEIVED SIGNAL BACK TO AN OPERATOR USING THE REPEATER FOR HANDHELD TRANSCEIVER OR ANTENNA TESTING. THIS COULD BE A 1 MINUTE TEST OPTION THAT IS PRE ACTIVATED BY A TOUCH TONE. WHEN A 2 METER RUBBER DUCKIE ANTENNA IS ATTACHED TO THE DEVICE, THE ANALOG METER READS ABOUT 0R6 V. AN RF THRESHOLD JUMPER IS INSTALLED AT THE 52 DBM POSITION TO KEEP LOCAL RF SIGNALS BELOW THAT FROM TRIGGERING ANNOUNCEMENTS. WHEN A 50 MW FM 146 MHZ SIGNAL IS TRANSMITTED FROM A HANDHELD TRANSCEIVER HELD 2 FEET AWAY FROM THE DEVICE, THE METER READS 1R8 V AND DEVICE ANNOUNCES 10 DBM USING TWO MORSE CODE CHARACTERS FROM ITS SPEAKER AFTER THE CARRIER DROPS. THE INSERTION LOSS OF THE 146 MHZ RF FILTER USED HERE IS APPROXIMATELY 5 DB. THE DEVICE CAN BE CALIBRATED BY FOLLOWING INSTRUCTIONS IN THE AD8307 LOG AMPLIFIER DATASHEET. WITHOUT CALIBRATION, THE AD8307 USUALLY REPORTS A LEVEL OF ABOUT 3 DB HIGHER THAN THE ACTUAL LEVEL. THIS CALIBRATION MAY NOT BE IMPORTANT TO MOST USERS BECAUSE THE DEVICE IS USED ONLY FOR RELATIVE RF SIGNAL STRENGTH MEASUREMENTS. USING THE DEVICE FIGURE 4 SHOWS THE REMOTE RF LEVEL ANNUNCIATOR ATTACHED TO A MIDLAND 13 520 2 METER HANDHELD TRANSCEIVER SET TO 146R52 MHZ. A DIPOLE RECEIVING ANTENNA TUNED TO 146 MHZ IS ATTACHED TO THE SET. THE TEST ANTENNA AND KENWOOD TH F6 TRANSCEIVER ARE NOT SHOWN. WHEN THE TH F6 FM HANDHELD TRANSCEIVER IS KEYED ON 146R52 MHZ USING ITS ORIGINAL RUBBER DUCKIE ANTENNA HELD HORIZONTALLY TO MATCH THE POLARIZATION OF THE DIPOLE RECEIVING ANTENNA AT SHOULDER HEIGHT ABOVE GROUND, AND FROM A DISTANCE OF 30 METERS, THE DEVICE ANNOUNCES THE LEVELS SHOWN IN TABLE 1. WE WOULD EXPECT A 10 DBM DROP FOR THESE POWER LEVELS PER 10 DB REDUCTION IN TRANSMITTER POWER, BUT WE DO NOT KNOW WHAT THE OUTPUT AMPLIFIER OF THE TH F6 IS DOING RELATIVE TO A POOR PERFORMING RUBBER DUCKIE ‰ END OF 40 WPM TEXT ‰ QST DE W1AW ƒ