9:1 Impedance Converter (BALUN) for RTL-SDR with BNC Connector

9:1 Impedance Converter (BALUN) for RTL-SDR Long Range Antenna with BNC Connector

This impedance converter can be used with a long wire antenna (or any wire) for HF reception on RTL-SDR with an upconverter. The impedance of the long wire antenna is approximately 450 Ohms (very approximately, impedance varies with frequency and length). The 9:1 BALUN allows matching to a 50 Ohm receiver, which is close enough to the 75 Ohm input of the RTL-SDR. A small amount of impedance mismatch has no significance for RX, but a larger mismatch can lead to deterioration of reception.

With an operating frequency of 100K-50MHz, small dimensions, easy assembly and disassembly, it is suitable for outdoor use and QRP use.

Note: For long-term outdoor use, the top and bottom covers of the housing must be glued and sealed with silicone.