Tagged: impedance matching

Tech Minds: Testing a High Impedance Amplifier for Software Defined Radio

Antenna impedance matching is important for antennas and software defined radios as impedance mismatches can result in poor reception. For transmitting SDR's the situation is more dire because impedance mismatches can actually damage the transmitting hardware or at least cause high power efficiency losses.

Over on his YouTube channel Tech Minds has uploaded a video where he tests out a battery powered HF high impedance amplifier for software defined radios. The amplifier is designed to be used with long wire antennas on the HF bands as these antennas typically have high impedances which don't match the 50 Ohm impedance that most SDRs expect to see. This device is an amplified alternative to using a passive unun.

The results in his video show that the signal to noise ratio is indeed boosted when the impedance matching amplifier is used. Later the device is opened to show the battery, charging management chip and amplifier chip.

High Impedance Amplifier for Software Defined Radio

SignalsEverywhere: Improving HF Reception with Impedance Matching

This week on the SignalsEverywhere YouTube channel host Corrosive explores why impedance matching matters when trying to obtain the best reception possible. To do this he reviews the NooElec 1:9 Balun, which is designed to convert the (roughly) 450 Ohm impedance of a long wire antenna or ladder line dipole back down to 50 Ohms, which is the standard impedance that an SDR expects. Small amounts of impedance mismatch are negligible for RX, but larger mismatches can result in poor reception.