SDR Software Defined Radio

Is there any info about using SDR with RISC OS hardware? Tks

Only comment/idea I can make is: I wrote a capture program for using the FUNCubeProPlus SDR on Linux. Thus presents mainly as a USB ‘audio’ device for capture, so porting that should be feasible. Can’t comment on the cheaper SDR dongles as I never got round to useing one.

I’d Love to see an ADALM-PLUTO usable though! Keep meaning to buy one. Works from zip to about 6Gigs as well.

Tks for the reply.

How much of the radio is in the USB Dongle Funcube?

Any info how you talk to USB Dongle from RISC OS?

Found a eBook/PDF on -Software Defined RADIO for ENGINEERS – 375 pages.

Pity RO PDF doesn’t read out loud the text :-)

Can you plug a Android phone into a Iyonix via USB – to copy files over?

The FUNCubes operate as a form of ‘downconvertor’. You give them the nominal frequency to tune to. They then use an ‘IQ demodulation’ method.

The result comes out as a series of pairs of values representing a complex number. This ‘downconverts’ the RF input into the ‘audio’ baseband output.

So for the sake of example, imagine the wanted RF is a carrier at 100MHz. If you set the FCPP to tune to 99.99 MHz i.e. 10 kHz lower, the output is a series of IQ values that vary sinusoidally at 10 kHz. If the RF level goes up and down, so does the output at 10kHz. Because the output is a series of complex numbers the direction in which the IQ ‘vector’ rotates distinguishing an input components at 99.99 MHz from one at 100.01 MHz

Bottom line is that you then demodulate this by using your program to process the output.

Afraid I’ve forgotten how the commands are sent as I wrote the programs for mine years ago. But the source code for Linux (in ‘C’) is in what I’ve made available.

The FCPP has one particular strength. This is the high dynamic range as it outputs 16 bit values scaled from 24 bit readings. Most cheap SRD dongles only output 8 bit values. However they can run a higher sample rate and are a lot cheaper. So if you need wideband go for the cheaper dongles. But if you want precise measurements go for the FCPP.

If it is of any use, the following may help wrt the FUNCube.

http://jcgl.orpheusweb.co.uk/funcube/FUNcalibrate.html Shows the calibration results for the one I have. One point to note is that – unlike most SDR dongles – it has a set of band filters and a switchable low-noise preamp and variable ‘IF’ gain.

http://jcgl.orpheusweb.co.uk/temp/Spectrum.pdf Shows the kind of results I get from using it as a spectrum analyser. (In this case to monitor changes to the UHF DVB transmissions in my area.)

Bottom line probably is that the choice depends on what you want to do with the SDR. The FUNcubes were (as the name indicated) developed for people who want to get signals from ‘cube sats’ in low earth orbit. But can cover a wider range of uses.

I’ve not tried to use mine with RO. It accepts commands via USB, but I’ve forgotten the details so would need to check. There is a website and an email list for users. The output comes as if from a USB Audio ADC, so can be collected using the same methods as we can now use to make audio recordings via USB Audio, I suspect the way commands are given is similar to the ways other USB devices are controlled from the computer. But I did my software years ago and since then it has ‘just worked’ with my Linux laptops. Use these to give me a portable measurement instrument for RF.

The source code I use is on the web along with all my other RO and Linux software. So that may help. It’s in ‘C’.

Tks for your info.

Any detail’s on making a Android tablet speak a PDF book. It gives me the impression that it can.

Another choice is to dump the whole book as a text file into !Textease but no diagrams to follow :-(

Any detail’s on making a Android tablet speak a PDF book.

Is it available as an epub by any chance? Sometimes when I can’t sleep, I fire up Ereader Prestigio and have it read me some Lovecraft.

Some PDF files can be formatted weirdly which can make reading difficult, however @Voice Aloud can cope with speaking numerous things (websites, PDFs…).

[…]and have it read me some Lovecraft.

That will make sure you really can’t sleep!