Shielding the RTL-SDR
Over on Reddit user will1384 has posted about his imgur photo album that clearly documents some well researched steps that he took in an effort to shield the RTL-SDR dongle from interference. Interference is caused by strong out of band signals that can sometimes show up even when no antenna is connected to the dongle. Shielding the dongle helps to remove this interference.
The main steps he took were the following:
- Buy an aluminium case from ebay and put the dongle inside it.
- Remove the USB connector and ground the dongle ground to the aluminium casing using a 1M Ohm resistor and a 47nf ceramic disk capacitor.
- Connect the USB data lines to a USB extension cable and wrap a toroid around the 5v and GND lines and twist the two data lines together.
There is a discussion about this shielding project on Reddit.
I made the usb shield wiring from the diagram, but my computer doesn’t detect my rtl dongle and says “USB device not recognized” and a high pitched sound was emitted from the dongle. glad to see it didn’t get damaged. what should I do?
Does the dongle heat-up? being enclosed?
If you want a good cheap aluminum case consider inserting the dongle inside a broken hard disk.
In some models an upconverter may fit as well
Blocking the interference that comes through anntena needs more work . May be something like a freqency selector
Maybe shielded case and full galvanic isolation will be better solution? I’m thinking about ADuM4160 full speed digital isolator from Analog Devices and external noise-free 5V power supply.
Sorry… ADUM will not work… It isn’t high speed USB device. 🙁
47nf cap or 47m resistor? The diagram shows a resistor but the text mentions a cap.
My bad I see the cap now. I thought it was just a note on the resistor at first.