WA3TFS SDR Upverter Design
Contents
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.
- $55
- Purchased at W3PIE hamfest
- Can be ordered as PCB, Kit, or assembled
- SBL-1 Level 7 mixer
- 100 MHz can oscillator
- Low pass filter
- 35 MHz
- 1 kHz to 1.7 GHz SDR Receiver - WA3TFS Design
Schematic
Pass Filter
- 9 turns on FT37-2 = 0.3 uH
- LTSpice Simulation
- 1-100 MHz
- LTSpice Simulation
- 1MHz-1GHz
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
- SBL-1 mixer
- 30pF cap installed in J_A to J_B marked 300
- Build was 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
Wiring
Enclosure
- Board fits perfectly in
- Extruded Aluminum Enclosure Box - 94mm x 83mm x 30mm
- Card just perfectly matches
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