Morgain Antenna by DL6GD

This QRZ.com callbook entry by DL6GD details the construction and performance of a 40m/80m Morgain folded dipole antenna. The resource includes a schematic diagram, construction photos, and tuning notes. The antenna, with a total length of 20.30m, was mounted at a height varying from 4m to 6m above ground. Construction utilizes 0.75 sq mm transparent insulated copper wire, with Plexiglas spreaders (5mm thick, 70x10mm) spaced at 25mm intervals, secured with hot glue. A waterproof junction box houses the feedpoint and balun.

Tuning involved adjusting wire bridges for resonance on each band. On 80m, an SWR of 1.1:1 was achieved at 3.657 MHz, with an SWR of 2.7:1 at 3.580 MHz and 2.5:1 at 3.755 MHz, yielding a bandwidth of 175 KHz. For 40m, an SWR of 1.1:1 was measured at 7.100 MHz, with 1.5:1 at 7.000 MHz and 1.3:1 at 7.200 MHz, providing a 200 KHz bandwidth. DL6GD notes that 80m tuning exhibits slight height sensitivity, while 40m tuning is less affected by height or 80m adjustments. Long-term observations from 2014 and 2022 document SWR degradation due to environmental factors like spiderwebs and ice accumulation, which can cause HF-conductive paths between elements.

DXZone Focus: Callbook Entry | 40m/80m Morgain Dipole | SWR Measurements | 20.30m Length