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MODULATION DEMODULATION SOFTWARE RADIO  MAKE YOUR OWN IF SOFTWARE DEFINED
RADIO SDR FROM AN EXISTING TRANSCEIVER, AND MEASURE PROPAGATION PHENOMENA
WITH MDSR AND SCANNING RF SEISMOGRAPH SOFTWARE.  ALEX SCHWARZ, VE7DXW THIS
ARTICLE IS BASED ON THE AUTHORS WORK PUBLISHED BY THE RADIO SOCIETY OF
GREAT BRITAIN, RADCOM OCT.  2016, VOL. 92, NO. 10.  TODAYS ANALOG
RECEIVERS, EVEN LOWER END ANALOG RADIOS, HAVE A DYNAMIC RANGE IN EXCESS OF
80 DB, AND ARE VERY AFFORDABLE.  THE MODULATION DEMODULATION SOFTWARE RADIO
MDSR SYSTEM ALLOWS THESE OLDER, PERFECTLY FUNCTIONAL RADIOS TO GET A SECOND
LEASE ON LIFE.  THE LOW INTERMEDIATE FREQUENCY LIF CONCEPT USES THE 455 KHZ
IF, AND DOWNCONVERTS IT TO 12 KHZ, WHERE IT CAN BE PROCESSED BY A SOUND
CARD.  ONCE THE SIGNAL IS DIGITIZED, THE DIGITAL SIGNAL PROCESSOR DSP
ENGINE OF THE MDSR SOFTWARE CAN PROVIDE SHARP IF FILTERS, NOTCH FILTERS,
AND A WHOLE RANGE OF SDR LIKE FEATURES THAT MOST ANALOG RIGS LACK.  THE
MDSR SOFTWARE ALSO ADDS A REAL TIME SPECTRUM ANALYZER FOR FAST TUNING AND A
REMOTE CONTROL FEATURE THAT IS EASY TO USE AND TO SET UP.  AT THE COST OF
AN LIF CONVERTER PRINTED CIRCUIT BOARD PCB SEE THE LEAD PHOTO, AND THE TIME
SPENT TO CONNECT THE TRANSCEIVER AND THE COMPUTER TOGETHER, THE MDSR SYSTEM
OUT PERFORMS MANY SDRS AVAILABLE ON THE MARKET TODAY.  COMBINED WITH A 24
BIT SOUND CARD, WHICH HAS A DYNAMIC RANGE OF ABOUT 120 DB, THE RECEIVER
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