ATU

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.