1. Watkins Johnson WJ-9477(G) Tunable Demodulator, Many Bandwidths, use as VLF-HF Receiver up to 30MHz

2. The region between Earth's surface and the ionospheric D-layer behaves thus like a waveguide for VLF- and ELF-waves.

3. The relative importance of these phase Bunchings in forming resonant currents in the generation process of VLF‐triggered emissions is …

4. Very low frequencies (VLF: 3–30 kHz), and extremely low frequencies (ELF: <3 kHz) are reflected at the ionospheric D- and lower E-layer.

5. Watkins Johnson WJ-9477(G) Tunable Demodulator, Many Bandwidths, use as VLF-HF Receiver, up to 30MHz, very nice! Just put a pre-amp in front of it.

6. It shows that this GRB was only visible above a height of about 210 km, that is much too high to affect the ionosphere layers involved in VLF propagation.

7. This is especially usefull to check if a GRB was visible at the sub reflective point of a VLF propagation path, and which layer of the ionosphere were illuminated.