The Loop in Ground project is about a receive only antenna for low HF, but usable from MF to HF. The objective is an antenna of that is small, low profile, and can be located outside the zone where evanescent modes dominate around noise current carrying conductors, like house wiring to minimise noise pickup.
To some extent, the project was inspired by KK5JY’s Loop on Ground (LoG).
This article presents a comparison of Signal to Noise Degradation metric (see Signal to noise degradation (SND) concept) for both antennas, the common elements being:
- based on NEC-5.0 models (as detailed in earlier LiG articles);
- soil parameters used are σ=0.01, εr=20 (calibrated to measurements at the LiG test site);
The LoG models are for 4.6m sides, 2mm wire at 10mm height above ground, and an approximately optimal 450Ω:50Ω transformer.
The LiG models are for 3.0m sides, 2mm wire at 20mm below ground, and an approximately optimal 200Ω:50Ω transformer.
Above is a plot of SND for both antennas over the range 0.5-15MHz.
They are quite different responses.
It can be seen that from about 3-11MHz there is not a lot of difference between the antennas, but the LiG degrades slowly above 11MHz whereas the LoG degrades quickly below 3MHz.
A work in progress…