In this episode Corrosive from the SignalsEverywhere YouTube channel begins a series on reverse engineering an old 90's Barbie branded 2.4 GHz wireless camcorder toy, and using it for Amateur Radio TV. The camcorder toy consists of the wireless camera, and a base station that plugs into a TV.
After taking the camcorder apart Corrosive discovered a potentiometer on the PCB which allows the transmit frequency to be adjusted, and that the camera's CCD sensor can actually output composite video, possibly allowing for improved video quality. In addition he found the datasheet for the main FM demodulator chip on board the base station, and saw that it is designed to operate from 350 to 550 MHz. So he speculates that elsewhere in the circuit is a 2.4 GHz downconverter which may be useful for other projects too.
Amateur Television 2.4 GHz Station Converted From Barbie Camera Part 01
Last week we posted about M Khanfar's YouTube video that showed how to decode Es'Hail-2/QO-100 DVB-S2 on Ubuntu with the LeanDVB decoder. However, the method he showed was not in real time as it involved recording an IQ file in GQRX first, then decoding that IQ file. Similarly we also posted last week about a Windows based real time decoder.
M Khanfar recently wrote in again and wanted to show that real time decoding is possible with LeanDVB. The method is to simply pipe the output of the rtl_sdr command line decoder in LeanDVB, and then into VLC. He notes that his PC isn't actually fast enough to decode in real time without lag, but a modern i5 CPU would work well. The actual terminal command is shown in his YouTube video description.
This is Realtime live DVB-S2 Decoding done , without need to record .RAW file , its live and easy method by one click ! In this video i decoding 2MS symbol rate from wideband transponder of QO-100 beacon , you can decoding 1MS , 0.5MS , 333KS , 125KS symbol rate ! The lower Symbol, the faster speed for decoding! , the Amateurs operators on QO-100 Uplink DATV DVB-S2 at 0.5 , 333 , 125Ks , so its easy to Live Decoding Now ! With very low SNR ! , so the normal SDR can coverage wideband beacon of 2Ms symbol and all Ham uplink ! , if you have an SDR that can coverage 27.5 mb of bandwidth, so you can easy decoding Live a standard commercial satellite channels! But it need a high speed Pc .
Yesterday we posted about a real time Windows demodulator for receiving amateur TV DVB-S/S2 on Es'Hail-2/QO-100. Recently another YouTube user "M Khanfar" also submitted a video tutorial showing how to decode Es'Hail-2 DVB-S2 on Ubuntu with an RTL-SDR and the LeanDVB decoder.
Khanfar notes that although the LeanDVB decoding method is not real time, his tests show that the LeanDVB method is able to work with a much lower SNR signal compared to the Windows demodulator. The process is to simply capture an IQ file with GQRX, then run LeanDVB on the command line with the recorded IQ file. It will create a TS file that can be played in any media player.
His receiving setup consists of an RTL-SDR, 100cm dish, modified LNB and a home made bias tee that can switch his LNB between horizontal and vertical polarization.
Thank you to Happysat for writing in and noting that over on the Amsat-DL forums user Markro92 has uploaded a realtime Windows DVB-S demodulator with GUI. The demodulator works with the RTL-SDR, HackRF, SDRplay and PlutoSDR support is due to be added soon. Happysat notes the following:
It can demodulate DVB-S and S2 signals with very low symbolrate on Es Hail-2 geosat on 25,9 East from the Wideband Transponder. So you do not need a modified lnb or modified satelitte stb :) Of course you can also see the amateur tv streams which people uplink theirself.
To see if there is any stream active one can visit the wideband WebSDR and above the stream the info is displayed which parameters in use (symbol rate and mode dvbs(2)) so you can adjust in the Demodulator program. Stream + Chat: https://eshail.batc.org.uk/wb/ .