VLF signals received in Costa Rica

Hi there.
In this video, I show various signals received at my QTH in San José, Costa Rica.

The signal A1F3 transmitter is very weak compared to other days. WWVB was able to be decoded after a couple of attempts. The signals are as follows:

18.3 kHz - HWU - France
21.4 kHz - NPM - Hawaii
22.2 kHz - JJI - Japan
23.4 kHz - DHO - Germany
24.0 kHz - NAA - Maine (USA)
25.2 kHz - NML - North Dakota
29.7 khz - A1F3 Negev Desert (Israel)
37.5 kHz - TFK - Iceland
40.75 kHz - NAU - Puerto Rico
60.0 kHz - WWVB - Colorado

After a few minutes, it appeared on the waterfall 19.8 kHz - NWC - Australia

My setup: radio Cloud IQ sdr (from RFSpace)
Antenna e-probe 8 m over the groud

Видео VLF signals received in Costa Rica канала SignalSat_CR