The Lemon Fool

No - I don't mean Schroders - I mean Software Defined Radio. Are there hordes of you out there deeply into this? Can I get some invaluable input into all of the useful things that I can do with this invention?
This all arose because of Covid-19 - and we won't have our children and grandchildren with us over Christmas. So I thought I would buy myself a new toy to keep me occupied. ( I also bought a pressie for the wife - but we couldn't bother wrapping them up, nor could we wait for Christmas).
So - for those of you who are interested, but not currently knowledgeable, its a little dongle containing an RTL2832U chip that attaches via a USB plug to a computer (in my case a Windows PC), and the other end attaches to an aerial. Then with a piece of software (CubicSDR) you can scan the air waves up to around 1.7GHz. I'm on a landing flight path, so I can listen in to aircraft (118-137MHz) - but their conversations are usually brief, and cryptic. I can also listen to the VHF/FM radio transmissions (88-108MHz). I have scanned, currently without success, the Amateur 144MHz band. And with another piece of software welle.io, I can turn the PC into a DAB Radio (174 to 239MHz). And with yet another piece of software (RTL1090) I can receive the ADS-B signals from aircraft at 1090Mz which provides tracking information. Ideally i should be able to plot this on a map display - but currently that's a work in progress. All software is free - and freely available.
So I'm hoping that there are others out there who are ahead of me on the learning curve - and can provide learned advice on how I can waste even more of my time. I should also add that I have a Raspberry Pi from a previous Christmas, so I could turn it into a dedicated SDR, since most (or all?) of the software also runs under Unix.
All help will be gratefully received.

Been a few years since I tinkered with this (helping an Estonian Java programmer get acquainted with "embedded" Linux) but looking in my notes I see these sites:
http://www.rtl-sdr.com/adsb-aircraft-ra ... h-rtl-sdr/
http://www.satsignal.eu/raspberry-pi/dump1090.html

You might have seen them already


-sd

Interesting, thanks for posting, I know only a little about these so won't be of much help, however I am interested in how you get on. Many years ago I got my Amateur Radio licence (G7SRV) and have been planning to restart now that I have more time on my hands. The two metre band is not as busy as it once was regretably, but you could try the local repeaters on 2 metres and 70 cms. The 6 metre band used to be good when you get a lift and the conditions allow long distance contacts. I was under the impression that aircraft and ATC used AM due to it's larger footprint, but maybe that's no longer the case, or your new toy can pick up AM as well? Anyway what you receive is very much a factor of how good your aerial is, in terms of it's design and location. Directional beams are great but obviously quite pricey to buy and install.

MM

MaraMan wrote:or your new toy can pick up AM as well? Anyway what you receive is very much a factor of how good your aerial is, in terms of it's design and location.

The CubicSDR package handles AM, Upper Sideband, Lower Sideband, Double Sideband, FM mono, FM stereo, and Narrow band FM.
And yes - the aerial (currently indoors) is a problem, although on the ADS-B signal from aircraft, I can pick up flights overflying around 35,000 ft from about 150km away. In my youth (60 odd years ago) I thought about getting an Amateur (transmitting) Licence - but I never spent the time getting fluent in Morse code - which was still a requirement. My science teacher at school had been a wartime radio operator in the Merchant Navy, so remained a keen Ham - but always with Morse Code.

servodude wrote:Been a few years since I tinkered with this (helping an Estonian Java programmer get acquainted with "embedded" Linux) but looking in my notes I see these sites:
http://www.rtl-sdr.com/adsb-aircraft-ra ... h-rtl-sdr/
http://www.satsignal.eu/raspberry-pi/dump1090.html

You might have seen them already


-sd

Thanks - I have already had a look at these sites. I'm particularly interested in the dump1090 utility which should provide a linkage to the mapping program, but I'm having difficulties in downloading it - I think my security software may be blocking it. As my other half says - it keeps me out of trouble.
PS - I had a go at Python (on a PC), copying part of your program which downloaded and displayed Covid-19 data. And I managed to get it to provide me with CSV files from the Government Covid-19 site- as per my CURL approach.

scotia wrote:

MaraMan wrote:or your new toy can pick up AM as well? Anyway what you receive is very much a factor of how good your aerial is, in terms of it's design and location.

The CubicSDR package handles AM, Upper Sideband, Lower Sideband, Double Sideband, FM mono, FM stereo, and Narrow band FM.
And yes - the aerial (currently indoors) is a problem, although on the ADS-B signal from aircraft, I can pick up flights overflying around 35,000 ft from about 150km away. In my youth (60 odd years ago) I thought about getting an Amateur (transmitting) Licence - but I never spent the time getting fluent in Morse code - which was still a requirement. My science teacher at school had been a wartime radio operator in the Merchant Navy, so remained a keen Ham - but always with Morse Code.

Yes I have a similar story, my father was in the Royal Signals just after the war, stationed in Trieste. He was very good at Morse, but I never got beyond 10 wpm and the standard for a class A licence at the time was 12wpm (early 1990's). I passed all the exams except the Morse test and had what was called a class B transmitting licence (above 30Mhz), but now is just termed a Full Licence and I can transmit on all amateur bands, including HF. I can still read Morse quite fluently, but a little more slowly than at my peak. My Dad could comfortably read and send accurately at well over 25wpm.

MM

MaraMan wrote: My Dad could comfortably read and send accurately at well over 25wpm.

MM

I've always been jealous of those who can read CW at such a speed. I managed around 15-16wpm reading, though I got up to around 20wpm sending with an electronic key (it probably went out as gobbledegook )
..._._

--kiloran

kiloran and MaraMan - I admire your persistence with morse code - I only made a desultory stab at it.
Back to the SDR - I found the bug that was inhibiting the download of more software - my PC was getting lost when attempting to extract the files using the default de-zipper. I switched over to 7-zip, and all was well. My biggest success was the download of adsbScope, which in conjunction with RTL1090 gives me a map displaying the overflying aircraft. Setting up adsbscope is not for the faint hearted - but if you are tempted, follow the instructions at Sonic Goose.