Transmission lines

QRP Antenna Tuner

QRP Antenna Tuner

DIY kit from Aliexpress or Ebay Thse kits are sold on Aliexpress and Ebay and at the time of wiring they cost about $13 USD shipped. Roots of this tuner can be traced to a QRP console designed by Doug DeMaw featured in QST article: “A QRP Console” Doug DeMaw, QST, Sept. 1970, p. 23-25. SWR indicator used in this tuner is based on Dan Tayloe design: SWR Indicator Bridge Kit N7VE LED SWR Bridge Manual LED SWR Schematic Tuner is using a high-pass T-network to match low input impedance (Z) to a high output Z.