No, the cheap rtl dongles are receive only because they are re-purposed TV receivers, and there is no companion transmitter. If you want to transmit, I HIGHLY

No, the cheap rtl dongles are receive only because they are re-purposed TV receivers, and there is no companion transmitter. If you want to transmit, I HIGHLY suggest you look into ham radio. It's cheap to get a license, under $50 to test and get your technician's license in the USA. That will give you a lot of legal opportunities to TX and you will learn quite a bit in the process. The ARRL technician study guide is a great book and if you get through it all you are pretty much guaranteed to pass the test (all the test questions are in the book). The test isn't a cakewalk but it's passable for most anyone who studies. The E4000 is out of production, but I think it gives ~500 MHz more receive frequency on the top end. It's really not game changing and the new R820T2 dongles seem to be better overall, but the E4000 is worth the extra $30 to lots of folks. You can get to higher freqs without an E4000 anyway. A popular "hack" is to use an MMDS downconverter (another $25 Chinese purchase) to get access to the 2.4 GHz bands and sniff bluetooth and wifi packets. This is fairly advanced stuff that goes beyond just listening to voice broadcasts that you are doing now since you will be trudging through some cryptically written tutorials and writing some of your own code to get everything to work. Some people just want to listen to voice, and don't need the extra frequency since you can listen to AM/FM broadcasts, civilian air traffic, ham VHF/UHF, and even military VHF/UHF with just a regular dongle. As far as synchronized dongles, a guy was running two dongles off of the same clock source (he soldered a wire between the two chips so they could use the same crystal). That way he could compare the differences from signals received at two physically separated antennas and track moving objects (like airplanes) that reflected radio transmissions. This is by far the most advanced project (I feel bad calling it a hack) I've ever seen with an RTL dongle, and most of the licensed hams I know don't have the brains to do it: http://kaira.sgo.fi/2013/09/passive-radar-with-16-dual-coherent.html http://kaira.sgo.fi/2013/09/passive-radar-with-16-dual-coher...