Difference between revisions of "WA3TFS SDR Upverter Design"

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Line 48: Line 48:
 
* Nice silver mica caps
 
* Nice silver mica caps
 
** My kit was missing the center cap of the band filter (150 pF)
 
** My kit was missing the center cap of the band filter (150 pF)
* I used a junk box ceramic disc cap
+
** I used a junk box ceramic disc cap
 
* 30pF cap installed in J_A to J_B marked 300
 
* 30pF cap installed in J_A to J_B marked 300
 
* Build was too tough due to very small pads on the PCB
 
* Build was too tough due to very small pads on the PCB

Revision as of 15:01, 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
    • My kit was missing the center cap of the band 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

Wiring

WA3TFS Upverter Wiring.PNG

Enclosure

WA3TFS Upverter P1878-720px.jpg

WA3TFS Upverter P1880-720px.jpg

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