This article documents a small experiment with a quite small untuned loop, and LNA and receiver on 80m to assess its ability to copy signals on the band as well as the station transceiver on large antenna.
A significant factor at 80m is that ambient noise is quite high. Let’s consult ITU P.372-12 for guidance.
Curve E is the median city noise, at 3.6MHz Fa is about 62dB. At a more detailed level, P.372-12 gives the median noise figure for Rural precincts at 51.8dB and that figure is more appropriate to the test location (large block rural residential).
The test was carried in a few spots, at 50-100 m from the main station dipole. Continue reading Small untuned loop with MMIC LNA on 80m