An ATU, AMU or transmatch forms an essential part of the HF radio shack, allowing us to use our transceivers with often less than ideal antennas and give us the multi-band and wide band coverage that we need. This week, Peter, G3RZP, looks under the hood at ATUs to reveal a little more about how they work, how they are constructed and examines the various techniques used for making an effective antenna matching circuit. Various methods are explored, including the classic L and T matches, and the commercial Z match. Peter shows us some homebrew tuners including a very impressive design made in a machine shop. Peter also looks at measuring antenna impedance, a process which forms the starting point when planning a matching network for any antenna and examines the real requirements for a remote tuner when things go wrong.
The talk will appeal to homebrew builders and antenna experimenters alike, and will help anyone aiming to optimise their HF antenna system using tuning networks.
Location: Saverake Street, Swindon, Time 7:30pm. Visitors: £1.