VK4ZXI

LimeSDR running DATV Express DVB-S TX software (1st draft) With the MiniTioune DVB-S RX, I have begun trying different TX using DATV Express software under Windows 10. The logical first hardware would be the DATV Express hardware TX, but having shifted rooms in the house, I have not been able to find; I know exactly where it was in the other room! The LimeSDR is a popular recent SDR dual duplex transceiver by Lime Microsystems using a new version of their own chip. Cost is about US$250, but they have just announced a mini version for about US$150. It replaces the popular BladeRF; I sold mine to by the new model. DATV Express TX software is available for the LimeSDR; https://discourse.myriadrf.org/t/windows-based-dvb-s-s2-t-transmitter-for-limesdr/1348 (https://wiki.myriadrf.org/LimeSDR-USB) . It worked well without any hitches on 23 cm, with both TX and RX running on the same computer. I am currently using my main PC, but will move it to my fast Dell laptop for project work. Wi...

MiniTiouner DVB-S receiver build (draft) Works well, some fiddly soldering. Gives me DVB-S capability Assembled version coming, about $100 from DATV Express group. Links Unique hardware: https://www.batc.org.uk/shop/minitiouner https://wiki.batc.tv/MiniTiouner_hardware_Version_2 https://wiki.batc.tv/MiniTioune_software https://www.videohelp.com/software/LAV-Filters All codecs: https://www.videohelp.com/software/sections/codec-packs https://wiki.batc.tv/File:Notes_on_building_the_BATC_v2_Minitiouner.pdf

Power measurements of DVB-T transmitters- first draft Introduction I have been puzzled for some time about how power of DVB-T amplifiers were measured relative to other modes. This is an important issue in DATV as DVB-T has been criticized as inefficient compared to DVB-S. It would appear that some of the debate comes down to how the power is measured. Most amateurs use simple diode power meters that do not give an accurate reading for DVB-T. In this post, I outline the theory and practice of measuring DVB-T power correctly with either a thermal power sensor meter or envelope power using a spectrum analyser. It is important that the correct measurements be used otherwise it is comparing apples with oranges. Different power measurements are accepted in amateur radio, vis, CW (peak power, key down) compared to SSB (peak envelope power). I wonder if another measurement unit for digital modes may be more appropriate, such as the data rate to the DC power input and spectrum width, ...