Today, the 10-kW transmitter with its roughly +5 Hz offset was noted with a weak carrier at 11:30 UTC, and snippets of audio at 12:30. The Jaguar spectrum followed the signal at mostly very low levels throughout the day. Then, prior to 17:00 the signal suddenly increased significantly. At the full hour their BBC World Service news bulletin was indeed very strong, and dominating over the usually strong Asian stations on 1017. Was I surprised? Very! Then a few minutes after, the signal started to fade, and eventually disappeared.
But Tonga sunrise today was at 17:38, and pre-sunrise signal enhancement is a well known phenomenon especially among radio amateurs. So a peak like that is really what you might expect, or at least hope for.
Curious if this was a one-day only event, I scrolled back the Jaguar spectrum a few days. And yes, although weaker due to propagation, the Tonga signal had the same characteristics several days back.
Below is the 1017 spectrum from 11:00 to almost 18:00 UTC, showing the Tonga signal level from fade in to fade out.
And to give you a perspective of Tonga in relation to Kongsfjord, and more importantly, the sunrise, see below.
But this "news" about a late Tonga peak might not be news at all. According to the Pacific-Asian Log, the previous sign-on time for Tonga was 16:50. So, we should have noted the signal before they went 24 hours. But since they were so "easy" to hear before close-down, we never bothered to check, did we. Or maybe someone did?