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           o  DC RX-YU1LM Serbian

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            o Tunable crystal filter

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o HF SDR transceivers

            o ADTRX1

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o VHF/UHF receivers

            o AR1

            o AR1B

            o AR1C

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o Complementary designs

            o Synthesizer RZ6HY

            o Miniwhip PA0RDT

            o OK2CPV SMT receiver

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HF DC (direct conversion) receivers

All published designs and materials are free for personal and non commercial use. Other use for commercial purpose are not allowed without permission of the author.

     I began building some HAM receivers as boy in age of 13 in elementary school . It was simple construction after that I build more and more and electronics become my professional orientation. HAM receivers become and stay my passion. Here are some of my constructions and I apologize that published materials are not prepared better.

          HF DC(Direct conversion) Receivers

   First receiver which I was build ever for HF was tube receiver without RF amplification called 0V2 .It was working good and enable me to listen short waves and HAM bands. After that I built super heterodyne receivers but when I built DC transceiver by W7EL at the beginning of 80’s ZL2BKW version I was surprised how good DC receiver can be. With simple dipole antenna for 7MHz I worked 102 DXCC in 1985/86 with not to often work and with output power 1W ( BD135 output transistor). After that I made a lot of HF and VHF DC receivers HAM and for professional use, my or other authors design. In year 2000 I made presentation in KKE club Belgrade with subject “Renaissance of  HF DC receivers”. Paper material contains 30 pages collected materials about DC receivers with schematics, useful formulas for calculation ,PCBs and complete receivers made or design by author. I apologize that this materials are written on Serbian language but schematics, formulas and PCBs are useful for everyone who is in touch with the DC (direct conversion receiver) subject. I received  over 40 E-mails for translation in last few months and in translation I added several photos of realized PCB from article.

          RXDC-YU1LM-Serbian .pdf 

          RXDC-YU1LM -English .pdf 


          DC  receivers or subassemblies  built by author YU1LM


          SDR RX DR2H++ ,DT1A ,YU1LM AF shift network and IQ-PRO AD9854 DDS LO DC transceiver built by

          Jean-Michel TR8JH        


         DC 14 MHz QRP transceiver realized with modules from DC RX article built by  Duško YU1RK


          DC RX for 3.5MHz combination DR2A SDR RX modified for DC RX and audio phase shift network with drivers

       built by my friend Duško YU1RK


          DC RX for 3.5MHz with VFO from DC receiver article built by Miki YU1KM