Dupa ce m-am lamurit cit de cit despre ce-i vorba si am vazut (mai degraba auzit) "la lucru" un astfel de receptor on-line pus la dispozitia amatorilor de Universitatea Twente din Olanda, accesibil la adresa http://websdr.ewi.utwente.nl:8901/, am vrut sa-mi construiesc propriul receptor SDR.
Scotocind pe web am descoperit un foarte interesant site al radioamatorului sirb Tasić Siniša-Tasa (YU1LM) : http://yu1lm.qrpradio.com/ cu realizari deosebite in domeniu.
M-am hotarit sa construiesc receptorul denumit DR2-2 care nu are nici o bobina in componenta, insa autorul declara ca rezultatele sint foarte bune chiar cu acest receptor simplu.
Asa arata receptorul meu:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgS2RIDjs8cBzCYYP1VbwTHF2oSktBr67us67HPdhqZAOnpZVy4wo2ctvpgPCD_GNF_FY4UktwWr4jsepqnFMGvpZ8qOML4VFNNM0WA-vePbt30YBVjmLEB0hT21Uwz6QY2EDezB6BKtuU/s320/DSC03640m.jpg)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjniAwlVEffip6ijkTJQL65iVluGpBooKJ6zgA6qhlhXbWhCC5Qmg2HXyC4ozdn8ih7qCEPPNYOiP3cznGwF_Fx1EO77Bh_QRfMBU-j87fOVH_kGtAu2L_PR2cswl4wyTVfDZ9K_tuawTU/s320/DSC03668m.jpg)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhz-Hua8SqutMI0w0Qxq7Tw6-uGUPLHdiGsSi8Ynngmr04ekkzrmdHp4XdYq3vlRsy319EaAqWeY8BSOitNWXs7kCPg3BXgyJZ4jKwtDn9Y_v73gz2sD2EmKLmR6H-4hIMiwRZb9jtPzKQ/s320/DSC00220m.jpg)
Si oscilatorul local:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjruvTxUua8zRXVFgBrRFch3P-oBf8QlcdWjJqyhQVshbfNJTaQsI_sHwUQUaDYKMJ2TYBBrfMkXI0hVbqQrm6A5FyHQDzsKCuU1XpK6ois1f2QV-Fz5uMNQP4xlZaU26HSaw9Mw-8yCVY/s320/DSC03090m.jpg)
Am testat citeva soft-uri pentru receptia SDR, dar cel mai mult mi-a placut M0KGK SDR Decoder:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPukuwS-Cyb7B8_KrX_agfrXohvhNMYtAih2z8FzHNN7WlAtK22kUes4JdLX5F8HJ_L3TXZzdyMfx045Yfb1GU09ofeJtRHzAxGF7x9AqgEpABEKMGssfSebz4EHwQUlRphyphenhyphenMkN_TNU9g/s400/SDRrec2m.jpg)
Am folosit o antena activa de forma unui loop patrat cu latura de 2m montata pe timplaria de lemn a balconului si preamplificator cu doua tranzistoare bipolare de uz general.
Receptia este intr-adevar foarte buna, nici nu ma asteptam la asa performante. Am participat cu acest receptor in Campionatul National de Unde Scurte al Romaniei - SSB 2009, categoria SWL, obtinind rezultate bune. Merita pe deplin efortul!