SIRIO Quarter Wave Ground Plane Antenna for 40 MHz

While it is pretty easy to build an antenna for 40 MHz, the difficulties of mechanical strength and waterproofing are always a problem. Some may considering buying a commercial antenna and this is an example of one from SIRIO.

The SIRIO GPA is a basic quarter wave ground plane antenna and there are several models available to cover various frequency ranges.

GPA 27-45: 27 … 45 MHz Tunable
GPA 40-70: 40 … 70 MHz Tunable
GPA 66-108: 66 … 108 MHz Tunable
GPA 108-136: 108 … 136 MHz Tunable
GPA 135-175: 135 … 175 MHz Tunable
GPA 170-230: 170 … 230 MHz Tunable

As there are no loading coils, it's just a case of adjusting the length of the vertical radiating element and each of the three ground plane radials.

SIRIO 5/8 ground plane antenna for 40 MHz

The Italian firm SIRIO manufacture vertical antennas that cover 36 to 60 MHz. The TORNADO 35-42 model covers 35 MHz to 42 MHz which would tune nicely to the new 40 MHz (8 metre) band.