RTL-SDR upconverter po shemi i odlicnim uputama na http://www.snw.uba.be/page68.html
oscilator 54,000 MHz , mikser NE612AN 14,100 MHz rtl-sdr receiving freq = 68,100 MHz
ovo je konverter za websdr-9a1cig

oscilator 54 MHz

mixer

making coil
odlično objašnjenje “miksanja” za rtl-sdr prijemnik od w2aew: