User:Mjb/RTLSDR

I have a USB dongle with a terrestrial digital TV (DVB-T) receiver in it.

DVB-T is the digital TV broadcast standard used in a large part of the world, but not in North America, where I live, so I cannot use the dongle to pick up any TV signals here. North America uses the ATSC standard, not DVB-T. Technically ATSC can be decoded in software from the signal provided by a DVB-T device, but only if the device has 6 MHz bandwidth, whereas the typical cheap dongles have only 2.8 MHz. More info: https://www.rtl-sdr.com/watching-atsc-tv-with-an-sdrplay-sdr-and-gnu-radio/

My dongle is based on the Realtek RTL2832U chip. Tinkerers have figured out that these devices make for nice, cheap radio receivers that can be used with software defined radio (SDR) apps. Thus, this type of dongle, or the use of this type of dongle in this way, is called "RTLSDR".

My dongle uses what many consider to be the best tuner chip, the Elonics E4000. This chip has a defined range of 64–1100 MHz and 1250–1700 MHz, and is said to be capable of 50–2200 MHz, which looks about right; I can get it down to 51 MHz in SDR#.

(Compare to my portable radio receiver, the Grundig S350DL, which covers 3–28 MHz, the FM radio band of 87–108 MHz, plus the MW (AM radio) band of 0.525–1.71 MHz.)

RTLSDR on Windows

Setup

As per info and instructions at rtlsdr.org, plugging in the dongle will result in Windows installing a device driver for it. This driver is useless; you have to replace it by downloading the proper driver and then running Zadig, which is the official GUI front-end for libdwi, a generic installer for USB device drivers.

I didn't notice until too late, but there's an automated installer script at rtlsdr.org which will do most of the initial setup for you:

• Download a replacement RTLSDR driver from Osmocom. You need the 32-bit driver, even on 64-bit Windows (probably because SDR# is a 32-bit app).
• Download Zadig.
• Download SDR# (the nice GUI radio app) and its RTLSDR plugin from sdrsharp.com.
• Unzip SDR# into a new sdrsharp subfolder, relative to wherever the script is run from.
• Copy the SDR# RTLSDR plugin DLLs and modified config file to the sdrsharp folder.
• Unzip the 32-bit RTLSDR driver DLL (even on 64-bit Windows, this is what you need, I assume because SDR# is 32-bit) into the sdrsharp folder.
• Unzip Zadig into the sdrsharp folder.
• Dispose of temporary files & folders.

However, even if you use the automated installer script, you still have to run Zadig yourself in order to install the RTLSDR driver! Just plug in the dongle and follow the instructions at rtlsdr.org to choose all the right options, then click Replace Driver. (I am guessing Zadig notices the driver DLL sitting in the same directory as zadig.exe).(?)

Now you should be able to run SDRSharp.exe.

Using SDR# (SDRSharp)

Near the top left corner of the window, you choose the input source. It is set to "Other (sound card)" by default, but if all is working, you should be able to set it to "RTL-SDR / USB". This option won't appear in the list if the SDR# RTLSDR plugin didn't get installed, and choosing it will produce an error if the driver didn't install or if the dongle isn't plugged in.

Then press Play... and have fun.