Difference between revisions of "WA3TFS SDR Upverter Design"

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[[file:WA3TFS_Upverter_pcb_r11.jpg]]
 
[[file:WA3TFS_Upverter_pcb_r11.jpg]]
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=== RTL-SDR ===
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* Has SMA connector
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[[file:RTL-SDR_improvements_v3new800x800.jpg]]
  
 
=== Wiring ===
 
=== Wiring ===

Revision as of 16:17, 14 October 2021

WA3TFS Upverter P1874-720px.jpg

Features

SDR up-converter/receiver shifts HF (0-30 MHz) frequencies up by 100 MHz. Used to listen to HF frequencies on an inexpensive RTL-SDR module.

Schematic

WA3TFS Upverter Schematic.PNG

Pass Filter

  • 9 turns on FT37-2 = 0.3 uH

WA3TFS Upverter Inductor.PNG

  • LTSpice Simulation
    • 1-100 MHz

WA3TFS Upverter Pass Filter.PNG

  • LTSpice Simulation
    • 1MHz-1GHz

WA3TFS Upverter Pass Filter 1MHz-to-1GHz.PNG

Software

Build

  • Nice silver mica caps for the band pass filter
    • My kit was missing the center cap of the band pass filter (150 pF)
    • I used a junk box ceramic disc cap
  • 30pF cap installed in J_A to J_B marked 300
  • Build was too tough due to very small pads on the PCB
    • Particularly tough to solder ground pads
    • Pad shapes were not round so less area to set soldering iron
  • Is LO drive more than 7 dBm?
  • Pin 1 orientations on the mixer and oscillator "backwards" from other board legends
    • Pin 1 shown in red circle

WA3TFS Upverter pcb r11.jpg

RTL-SDR

  • Has SMA connector

RTL-SDR improvements v3new800x800.jpg

Wiring

  • SPDT switch
    • One switch pole powers the card (turns off 12V)
    • Other switch pole switched in/out the Upverter
    • Could just move the cable

WA3TFS Upverter Wiring.PNG

Enclosure

WA3TFS Upverter P1878-720px.jpg

WA3TFS Upverter P1880-720px.jpg

Videos by others