I have had a little time now to play around with my low cost Digital TV dongle. It works well enough, the specification that came with it stated the frequency coverage to be 48Mhz up to 863 Mhz. It is however wider than that. I have detected (very) local signals in the 27Mhz range and the unit works up to over 1Ghz.
Using a program called RTL1090 in conjunction with the "Planeplotter" software I am able to decode live position transmissions on 1.090Ghz from aircraft flying locally. All this using the tiny "mag mount " antenna which is about 15cms long that came with the dongle. The antenna is sitting on top of my R1000
receiver on the shack desk. Now personally this is part of the hobby (receiving aircraft transmissions etc) that I have never been particularly interested in but it is quite compelling to see the aicraft symbols pop up on the screen and amazing to see what this little device can do.