The implementation of digital television in Australia uses VHF channels 6-12 and UHF 28-69 exclusivley. This simple antenna is designed to cover those frequency allocations. This is an array of 6 cross-connected dipoles, similar to the Log-Periodic antenna design. Each λ/2 dipole has been "cut" for the available channels in my service area (Perth WA), these being; VHF Ch 6/8/11/12 & UHF Ch 29/32 (see graphic below). Inter-element spacing is λ/4 of preceding dipole (running lowest to highest frequency - also see graphic) Balun has 1:1 or 4:1 impedance matching: S.O.T. (select on test) for best "off-air" reception. I have no way of determining; antenna 'impedance' or any variation over the frequency range. Ideally it would be 75 Ω to match the coaxial cable. For construction: I recycle, dismantled Australian Hills brand domestic TV aerials. |