Maybe it’s because of my age, or maybe it’s because I’ve seen it happen live (I won’t go down that road now, but at 12 I had a Vic-20, at 14 a C64, and so on…), but I’m in the bunch convinced that a ham should try something new every day of his life! So, since I’ve read the first time about the RTL-SDR project, I decided I’d go deeper. First was to secure a DVB-T stick featuring the RTL2832 U chip. I checked the compatibility list updated on the Reddit dedicated to the project and, from the comments, I learnt that buyings from Asia were a hard path. That led me to explore European home electronics selling sites. I started from one in my Country, that had a LogiLink VG0002A.
Regarding this particular model, beware about one detail. At first, it appears on the compatibility list as useful for the project. Then, there is another line where, under the same brand and model, you have a not compatible device. The difference is due to the chip in the key. First model has the RTL2832U and works. Second one mounts an IT9135 and it’s consequently useless. The difference is easily not known to the seller. So, you have to learn to recognize them by the shape. Working one is in these pictures. The not compatible, instead, looks this way. The thing gets complicated by the fact the picture you have on online sales is normally no more than an example. By ordering with the same seller, I’ve been lucky and received the opportune model, but a friend got the second one. If you choose this stick, and don’t have a chance to physically inspect the item, bear in mind what you’ve just read.
Next step was installing the software on my personal computer (a Toshiba notebook, Intel Celeron (M) 1.40 GHz). On that side, the ground I decided to walk on was the “suite” by Balint Seeber, based on the “ExtIO” plug-in to “connect” a device to SDR applications like HDSDR or WRplus (that are installed too, all by launching just one file!). I’m not that Nerd, so I won’t get in the installation details. The Wiki (and the video linked in it) are the best guide one can ask for. The executable by Balint is very easy to go through, and the install was completed in minutes. Take care just about one detail: the USBlib .dll files built at the beginning of the install have to be in the folder of the SDR reception software. Otherwise, you won’t be able to select the ExtIO as input. In my case, I had to move then manually, but it was smooth, and in minutes I launched HDSDR.
My tests were made in the worst possible configuration, as I used the key not connected to an external ham band antenna, but to the DVB-T “stub” that came in the box of the USB receiver, putting it on the desk, close to PC. It’s no secret it’d not resonate properly on our frequencies. As for the results, you can read them in the article that the one and only Andy Lawendel devoted to my “test drive”, complete of vidcaps and audio recording links. To summarize my thoughts, I’d define the experience “encouraging”. I received signals (I engaged myself in QSOs, transmitting with a Baofeng UV-3R, outside my home, while the RTL-SDR was left on the inside, recording) on 2 mt. and 70 cm. Most of all, I had positive reception of signals on the 6 mt. band too (when the project specs say sensibility should start at around 67 MHz)! The main weakness of this solution is the “front-end” absence (in the repeater reception, my transmission on the input frequency, even if at 20 meters distance from the USB key, made “dumb” the receiver on the output!). However, this experience is teaching me lots of things on SDR (at a 20 bucks price!), and I’m sure that connecting the key to an external antenna, as well as performing more tests, could end in some surprises. Stay tuned!
73 de Chris!