by Cliff Pulis, KE0CP SDR Presentation - Cliff Pulis, KE0CP 1

Transcription

1 by Cliff Pulis, KE0CP SDR Presentation - Cliff Pulis, KE0CP 1

2 Basic Receiver Principles Mixing Frequencies Hetrodyn ing The IF Amplifier SDR Principles & Quadrature Phase (IQ) VHF / UHF DVB-T Dongle SDR Software The SDR Up-Converter Kit Does it Work? Cost SDR Presentation - Cliff Pulis, KE0CP 2

3 Antenna Ground system Tuner Detector (demodulator) Reproducer SDR Presentation - Cliff Pulis, KE0CP 3

4 Result is f 1 + f 2 and f 1 f 2 10,000 Hz and 9,000 Hz result in 19,000 Hz and 1,000 Hz SDR Presentation - Cliff Pulis, KE0CP 4

5 Hetrodyne mixing 2 frequencies Superhetrodyne mixing 2 signals when one is supersonic above our range of hearing A mixer or product detector mixes 2 frequencies SDR Presentation - Cliff Pulis, KE0CP 5

6 In a real radio need to amplify weak RF signal Amplifier needs good characteristics Wide bandwidth, low distortion, reject unwanted frequencies Mix RF and Local Oscillator (LO) so output is always centered on a fixed frequency Called: Intermediate Frequency (IF) Amplifier SDR Presentation - Cliff Pulis, KE0CP 6

7 This is a single-conversion superhetrodyne receiver. A dual-conversion would have 2 LO s & IF amplifiers. Many Ham receivers are triple-conversion superhets. SDR Presentation - Cliff Pulis, KE0CP 7

8 If LO frequency is near or at RF signal s frequency we can retrieve the modulation. We can demodulate the Audio signal with Analog to Digital (A/D) converter Digital Signal Processing (DSP) Need stable LO & computer for A/D & DSP SDR Presentation - Cliff Pulis, KE0CP 8

9 If 2 waveforms 90-degrees out-of-phase are amplitude modulated the result is called Quadrature Amplitude Modulation The In-phase component is I. The 90-degree shifted component is Q: thus I-Q. With DSP both the I and Q components can be extracted demodulated. SDR Presentation - Cliff Pulis, KE0CP 9

10 SOFTWARE: SDR# Zadig 7-Zip Antenna DVB-T Dongle Software PC (VHF/UHF Rcvr) SDR Presentation - Cliff Pulis, KE0CP 10

11 Antenna In Bandwidth: 64 MHz to 1,200 MHz USB Out to computer Also want HF: 0.5 to 30 MHz We still need demodulate the signal computer & DSP software SDR Presentation - Cliff Pulis, KE0CP 11

12 SDR# (SDR-sharp) software on PC (Free) Tuning Control Demodulation Digital to Analog conversion Amplification SDR Presentation - Cliff Pulis, KE0CP 12

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14 Need an Up-converter to: Shift incoming HF up 125 MHz 1.8 MHz MHz (160 Meter Band low f) 29.7 MHz MHz (10 Meter Band high f) Use Oscillator & Mixer IC s on a pc board This is the Kit you can build SDR Presentation - Cliff Pulis, KE0CP 14

15 DVB-T Dongle: $31.90 (includes shipping) Dongle price has dropped to about $10. SDR Up-converter kit: $36.90 (includes shipping) By Hayseed Hamfest Total without cabinet, etc. is under $50 SDR Presentation - Cliff Pulis, KE0CP 15

16 Newsky DVB-T Dongle -or equivalent- SDR Presentation - Cliff Pulis, KE0CP 16

17 Surface-mount 125 MHz Oscillator SDR Presentation - Cliff Pulis, KE0CP 17

18 Tin the 4 pads Solder in place SDR Presentation - Cliff Pulis, KE0CP 18

19 Voltage Regulator 125 MHz Oscillator Antenna Relay Mixer/LO SDR Presentation - Cliff Pulis, KE0CP 19

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29 Demodulator: RTL2832U Tuners: Elonics E4000 tuner (52 2,200 MHz with gap from 1,100 1,250 MHz) Raphael Micro R820T tuner (24 1,700 MHz with no gap) Dongle / Stick: RTL2832U / E4000 such as Realtec or Newsky, etc. RT-2832U / R820T Raphael Micro, DX, etc. Will need antenna adaptor TV PAL male etc. to type F female SDR Presentation - Cliff Pulis, KE0CP 29

30 You need 2 pieces of software both free Zagdig is a driver needed for each USB port you connect the radio to. SDR# is the UI software to run the radio Both programs are available at: Zagdig USB driver Sdr-install.zip SDR Presentation - Cliff Pulis, KE0CP 30

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34 The Elecraft KX3 10-watt Transceiver SDR Presentation - Cliff Pulis, KE0CP 34

35 Part Radio Shack # Cost Dongle / Stick: Realtec or Raphael, etc. $10 - $29 RANVerter 2.0 HF Up-Converter $36.90 Radio Shack Project Box 5-1/4 x 3 x $3.49 Size M DC Power Jack $3.49 Size M DC Power Plug $3.49 Chassis Mount SO-239 Connector $ ea. F Connector, 75-Ohm Chassis Mount $2.39 SPST Mini Toggle Switch $ mm PC Board Standoffs $ RG-6/U Coax Cable with F connectors $5.69 Total Radio Shack Parts $24.43 Total Up-Converter & R.S. Parts $61.33 SDR Presentation - Cliff Pulis, KE0CP 35

36 Send me an and I will send you the parts list and information on downloading the software: president@kc5our.com SDR Presentation - Cliff Pulis, KE0CP 36