----------------------------------- Emil 16 Feb 2018 10:29 ----------------------------------- @ Erwin Merci pentru flori. Linia hidrogenului nu este atat de spectaculoasa (parerea mea) apare pe waterfall un semnal care - in functie de obiect - este mai slab sau mai puternic. Problema majora este motorizarea antenei si (cu atat mai mult) calibrarea ei mai ales in cazul unei antenne off-set. Se poate folosi, pentru antene relativ mici, un EQ-6, insa problema majora (cu care ma lupt eu) este echilibrarea precum si spatiul relativ mare pe care un astfel de sistem il ocupa. Am gasit pe undeva niste sisteme de control pentru antene insa preturile sunt piperate deoarece piata este relativ mica (vezi https://www.primalucelab.com/radioastronomy/ ) Mult mai spectaculos este semnalul provenit de la radarul Graves care poate fi folosit pentru meteor scatter. Eu folosesc o antena KX-137 ( http://www.wraase.de/e_kd137.htm ) care, chiar daca este construita pentru receptia satelitilor NOOA da rezultate destul de bune pe frecventa Graves. Ideala ar fi o antena Yagi pe 144Mhz ( precum DIAMOND A144S10R cu 10 elemente si Gain de 11.6dBi sau DIAMOND A144S5R 5 elemente si Gain: 9.1dBi - doar ca exemple). Momentan folosesc un Airspy R2 ( 24 – 1800 MHz) si sper ca in martie sa primesc LimeSDR Mini (10 MHz - 3.5 GHz). Pentru meteor scatter folosesc HDSDR impreuna cu un program aditional care face screenshot la waterfall la intervale stabilite de timp astfel sistemul poate lucra in mod autonom. http://www.apritch.co.uk/help/md4.htm Inca netestat insa am planificata testarea. https://sourceforge.net/projects/echoes/ choes it's a radio spectral analysis software for RTL-SDR devices, designed for meteor scattering purposes. RTL-SDR are very cheap Software Defined Radios that uses DVB-T TV tuner dongles based on Realtek's RTL2832U chipset. Echoes doesn't demodulate neither decode any human-made signal. Its main goal is to analyze and record the total power of natural signals and generate screenshots and tabular data (CSV, GNUplot) output in presence of particular peaks in a selected narrow range of frequencies. Since there is no demodulation, there is no provision for audio listening, except for a notify sound when an event has been recorded. Features Captures waterfall spectra as PNG screenshots and statistics data files. Optionally generates GNUplot data files Multiple instances can manage separate dongles plugged in the same computer Three operating modes: continuos (records data only), periodic (captures data and screenshot every X seconds) and automatic (record data and screeshot each time a customizable (S-N) treshold is exceeded) HTML report production Installers ready for Windows7++ and RPMs / SRPMs for Linux xz binary package for Raspberry PI / Arch distro It can run headless, recording GNUplot and statistic data only