Wednesday, April 18, 2012

RTL-SDR: a really cheap, wideband SDR

One of the latest buzzs in the SDR world is the RTL-SDR Project.

The idea is to use the cheap (they used to be below US$11 and now start at US$20) Digital TV (DVB-T) receivers, which are intended to be used with PCs and have a USB interface.

 These are the innards of one of these units:

The compatibility list is expanding and, currently, accessible here:

What you get is a 64 to 1700MHz (*) receiver, with an amazing sample rate of 3.2MS/s (compare it to your soundcard!), a resolution of 8 bits/sample (not that great but enough for lots of purposes). And the best: software support for GNU Radio, Winrad, HDSDR, ... So far, there are decoders implemented for AM/FM, GSM, P25, ADS-B, TETRA, GMR, GPS, etc.

(*) (sometimes even more; there are some gaps at 1.2GHz or so) 

You can check the latest news about this project here:

It seems that all started here:

The way to integrate these receivers with a common SDR program, as Winrad, HDSDR, WRplus or other Winrad derivatives, is by using an external DLL, which can be found here:

There are already plenty of YouTube videos showing how they work. It is still a work in progress so don't expect to get them going withouth glitches but, at that price, it is worth the work :-)

I have got a couple units to experiment. I will publish here my results as soon as I get them working. This is what I got for less than US$11. The small box is the receiver!

Best regards and good luck with your SDR experiments!


Thursday, March 1, 2012

Flex-1500: QRP is an alternative

Last weekend I was able to contact an Special Event station, on 80m, using just the 5W my Flex-1500 provides. I had already logged the contact an hour earlier using a 200W rig (my Yaesu FTdx-5000MP) but I was curious about using QRP to do it, so I tried. And it worked :-)

So, yes, with patience, this small QRP rig works wonders.