The GP4 is a 1/4 wave vertical antenna operating on 4 bands (7 / 14 / 21 / 28-29 MHz). Thanks to its advanced design, it is not necessary to replace or adjust coils to change the operating band. It is designed for quick and lasting installations, both on the ground and on the roof.
TECHNICAL SPECIFICATIONS
- Total height: 5.65 meters
- Weight: 2.3 kg
- Wind resistance: Up to class 12
- Maximum power: 1000W PEP
- Configuration: 4 bands, 1/4 wave without coil changes.
RADIAL SYSTEM (GROUND PLANE)
The radial system is essential for proper operation. A "fan" layout is recommended:
- Minimum number: 7 radials.
- Recommended lengths: 6 radials of 2.5 m + 1 radial of 5 m.
- Height from ground: Optimal between 0.3 m and 0.5 m.
- Alternative installations: It can be mounted on balconies using the metal railing as a ground plane.
User tip: For fine-tuning the SWR, it is possible to slightly vary the arrangement or length of the extended radials.
PERFORMANCE AND TUNING
The antenna is designed to offer an SWR value of less than 1.5 at the following resonance points:
Center Frequency |
Bandwidth |
Estimated SWR |
7.050 MHz |
100 kHz |
< 1.22 |
14.180 MHz |
350 kHz |
< 1.22 |
21.200 MHz |
450 kHz |
< 1.22 |
29.000 MHz |
1.0 MHz |
< 1.22 |
