The RTL-SDR dongle is a fantastic tool for SDR enthusiasts, but the USB-A port can be frustrating when trying to connect to modern devices with USB-C ports. Out of this frustration, I designed my own USB-C adapter PCB to convert old USB-A RTL-SDR V3 and V4 dongles to USB-C. The mod consists in removing the stock USB-A plug on the dongle, and replacing it with a USB-C connector mounted on the adapter PCB.
Project motivation
I couldn't find any female USB-C adapter or breakout boards that were small enough to fit into the RTL-SDR dongle without the USB-C plug sticking out excessively. Existing solutions left the connector protruding too much, compromising the design's aesthetics and mechanical strength.
My solution
In my custom design, the USB-C connector sticks out only a few millimeters from the case, perfectly integrating into the original slot for the USB-A connector. The thickness of the adapter board "sandwiches" the USB-C connector snugly within the dongle's casing, creating a clean, compact look.
Key features
- Compact design: The USB-C connector extends only slightly beyond the dongle, maintaining a sleek profile.
- Full USB-C functionality: The adapter is equipped with 5.1k pull-down resistors, ensuring proper recognition and power negotiation with USB-C devices.
- Open source: The project is open source, with all design files available for anyone interested in creating their own adapter.
Building your adapter
If you're interested in building this adapter, you can find all the necessary files on my GitHub repository. The repository includes:
- KiCad 8 design files: For modifying and understanding the PCB design.
- Gerber files: Ready for manufacturing the PCBs.
- BOM and CPL files: For sourcing the components and for automated assembly of the boards (PCBA)
These resources make it easy to get started and build your own USB-C adapter for your RTL-SDR dongle.
How to install it?
- Open the case of your RTL-SDR dongle by unscrewing the 4 screws on the USB A side.
- Unscrew the locking nut on the SMA connector and make sure to remember the order they go in.
- Carefully slide out the PCB from the metal housing.
- Desolder the USB A connector from the board and clean the pads from any residual solder.
- Position the USB C adapter board in place of the old USB A connector, like in the pictures, and tack it in place with some solder.
- Solder all of the pins, including the two GND pads on the left and right sides of the USB C adapter board for mechanical strength.
- (Optional) Clean the PCB and the soldered joints using 99.9% IPA (isopropyl alcohol).
- Slide the board back in its metal housing, being careful of the thermal adhesive pad on the bottom of the PCB.
- Lock the SMA connector in place and screw back the front panel of the metal housing (on the USB side).
- Enjoy the USB C mod!
Prebuilt option
If you're looking for an adapter board that's already assembled and ready to install on your RTL-SDR dongle, I offer a prebuilt option that's perfect for those who want a plug-and-play solution without the hassle of sourcing and assembling components. Each board is handcrafted and fully tested before shipping. Check it out on my Tindie store or on Lectronz.
Conclusion
The USB-C Adapter for RTL-SDR transforms the classic RTL-SDR dongle into a modern device compatible with USB-C, without compromising its compact form factor. This project is a testament to how frustration can lead to innovation, making SDR even more accessible and enjoyable for enthusiasts.
Are you looking for a prebuilt USB-C adapter board? Check it out on: