After much time doing only microwaves activities, I listened the encourage words from Luis EA5DOM, to try to receive LF and MF . Luis is active in 136kHz and 477kHz in TRX and uses Opera, WSPR and have a SpectrumLab grabber.
Icom IC-R9000 and IC-781 used
On the right the PA0RDT mini-whip antenna
I build a PA0RDT mini-whip antenna and erected it 6 meters over the floor, as receivers I used my Icom IC-R9000 for 136kHz and the Icom IC-781 for 477kHz. I tested Opera, WSPR and Argo for QRSS.
WSPR-2 stations in 477kHz
WSPR-15 signals in 136kHz
Opera32 stations in 136kHz
G3XDV in slow CW QRSS/60 in 136kHz
DK7FC in DFCW in 136kHZ
The most common modes are OPERA32 (32 mins period), wspr15 ( 15 mins period) in 136kHz, and OPERA-8 (8 mins period) WSPR-2 (2 mins period) in 477kHz. The OPERA and WSPR uploads to Internet the receptions as spots and is possible check online the results and distance. This is feature is very nice to compare results with another stations.
wsprnet.org map with the WSPR-2 stations received in 136kHz
pskreporter.info maps with the OPERA-32 stations received at 136kHz
I’m really surprised for the good results and for the nice signals that can be received in this low frequencies with a small antenna. I know that this band some times not are easy for the local QRM/QRN generated by switched power supplies, motors, etc.. but with not much effort is possible get some setup to receive this bands.
I encourage that you try to receive this bands. A good point to start is the 477kHz band. It can be received easy using a base HF transceiver and antenna.