The 80-40-20-10 Meter Fan Dipole Project

Constructing a multi-band fan dipole for HF operation presents unique challenges, as VE2XIP demonstrates through his 2012 project to replace an existing commercial antenna. He details the process of calculating wire lengths using the 468/frequency formula, emphasizing the critical importance of equal leg lengths for each dipole element. The author shares practical insights gained from building at ground level, noting how elevation impacts resonant frequency and SWR, particularly for lower and higher bands.

VE2XIP's experience highlights the iterative nature of antenna tuning, starting with the lowest frequency band (80m) and working upwards. He provides a specific example of trimming calculations and offers a clever tip for accurate wire removal. The article also touches on the mechanical aspects, such as dowel spacing for wire support and the benefits of a pulley system for repeated raising and lowering during the tuning process.

Field results showed significant performance gains over the previous Alpha-Delta DX LB Plus, with 20 dB over 9 signal reports on 80m compared to 57. The project cost around $100 for hardware, proving a cost-effective alternative. The author also discovered a bonus 6m capability and achieved an inverted-V obtuse angle of approximately 115 degrees, contributing to a surprisingly stealthy installation.