GP4 Shortwave Ground Plane Antenna Vertical GP Antenna 4 Bands 7-14-21-29M. Description: GP4 4-band 1/4-wavelength shortwave GP antenna features working frequency of 7, 14, 21, 28/29M. It is suitable for long-term use outdoors and on the roof. No need to replace the coil to switch the frequency. Exquisite notch technology and superior electrical structure performance makes it a high-efficiency GP antenna. It is simple to lay ground net (more than 6 ground nets; length 2.5m/8.2ft or 5m/16.4ft), with a installation board. In principle, the more ground nets, the better. TheRead More