Software Defined Radio (SDR) and its Implementation Brandon Graham W0GPR

What is SDR Instead of relying on RLC circuits, a raw, lightly filtered analog signal is converted to the digital domain to be further processed by digital systems RF Front EndADC/DACComputer R.F. Front End High Quality Sound Card P.C., Laptop, Netbook, or Embedded processor Antenna I,Q

Digital vs Analog Digital Discrete Digital Signal Processing DSP Filtering Phase Frequency Time Power Analog Continuous Filtering Power amplifier

Flex Radio Manufacturer of SDRs for Industry, Military and Amateur use starting in 2003 HF transceivers ranging from QRP to 100 watts – Flex 1500 – QRP/transverter IF – Signature series – Contest serious radio – *Flex 3000 – *Flex 5000 – *SDR 1000 *discontinued

“The Feel of the Radio”

Power SDR Graphical User Interface (GUI) – Radio’s buttons and knobs Signal Processing – Filtering, DSP, Audio input and output shaping, etc Rig control – Frequency, band, tuner Program interface – VSPs, VACs, out to digital modes, logging, ext. aux

“The Feel of the Radio”

Computer system/Software VAC – Virtual Audio Cable VSP Manager – Virtual Com/Serial Port Com-0-Com DDU Til Logging Digital Mode Program Remote Operation Processor RAM Screen usage Quirks

The system setup Flex 3000 PowerSDR VAC DDU Til VSP Manager FL-DIGI WSJT-X N1MM+ Computer Com Single VAC Pair 1 VAC Pair 2 FireWire

Pros / Cons of SDR over Analog Pros Filter visualization Filter manipulation Control of settings Visually based displays – Panafall, etc. DSP systems and control Cons Quirky Visually demanding Computer intensive Software setup Need for multiple monitors and mouse Not EmComm Ready

“Let’s Play Radio”

Remote Operation Controlling computer, not radio Everything must be powered up at radio and ready for control Easier with digital over voice modes Lag Control of accessory programs and screens

WebSDR University of Twente – Netherlands Website designed for internet linked SDR receivers Mostly centered on ham bands. nte.nl:8901/ nte.nl:8901/ / /

Other SDR Systems $20 Dongle – Nooelec.com SDR SoftRock HPSDR ANAN Genesis Radio Rfspace Google is a friend! Always New stuff added Experimentation vs. “Solid Systems” Many different programs alsoftware.com/product s.php?cat=10 alsoftware.com/product s.php?cat=10