Antenna Systems
Our antenna systems are categorized as fixed and portable. All fixed antennas are located on an antenna farm at our observatory and are described on this page. They are used with the fixed receiver installations described here. The portable antennas generally are whip antennas of varying lengths and configurations used with ELF and VLF receivers. Click here for a description of our portable antennas and click here for a description of the receivers used with them.
Antenna Farm
The antenna farm includes a variety of technologies:
- Active loop antenna (150 kHz ~ 30 MHz)
- Active whip antenna (100 kHz ~ 30 MHz)
- Beverage antenna (~100 kHz ~ 30 MHz)
- Discone antenna (~100 MHz ~ 1 GHZ)
- Large Octagon Loop antenna (3 kHz ~ 150 kHz)
- HF log periodic antenna (18 ~ 32 MHz)
- Collinear dipole antenna ADS-B (L-band)
- Collinear dipole antenna Marine AIS (160 MHz)
- VHF/UHF log periodic antenna (50 ~ 1300 MHz)
- VHF/UHF log periodic antenna (144 ~ 500 MHz)
- Long-wire antenna (200 kHz ~ 30 MHz)
- Yagi antenna (20 ~ 21 MHz)
Click here for an antenna transmission line connection diagram. The transmission lines from each antenna are fed to a central location where the shields are bonded to earth ground at a grounding block.
The grounding block is made from two CATV-type grounding blocks. They are bonded to the earth electrode system by 12 AWG copper wire.
