DNB CI7 2.308MHz in for hours, propagtion type?

[Looking-Glass]

Today I came across CI7 on 2.308MHz CW transmitting continuous at the rather early hour of 0430z, which is 2.30pm local time in broad afternoon daylight with the Grey Line across the Pacific a long time off. The signal report was 419-519 but clearly audible.

The beacon is still audible at 0830z with a signal of 559 peaking 579 which is quite strong.

CI7 was not alone either with BH4 on 2.205MHz CW also noted in continuous transmission mode around the same time, similar signal report.

I am around 110kms direct line to nearest coast thus very far from the ocean where these beacons are. Also there is a mountain range inbetween.

Not a bad little effort from two low powered DNB's bobbing about in the Pacific, possibly off the coast of Sydney NSW would be the best bet I think.

Groundwave is probably the answer I think, but would appreciate comments from fellow HFU DXers.

[ChrisSmolinski]

It's winter down there, so I would expect the band to behave very similar to the upper end of the MW band. Here, I easily get daytime DX on that band of a similar range from TIS stations running 10 watts in AM mode. Reception of a several watt CW beacon seems quite plausible.

[Looking-Glass]

Just tuned to LD0 on 2.748 and it's been there Chris since 1.30pm local time or 0330z peaking 569 report, went to maps and the direct path from my place to the ocean is 110kms (68 miles) and there is the Blue Mountains between me and the coast, hard to figure.

Cannot hear any other beacons so I think LD0 must be off the coast of NSW between Wollongong to the south and Newcastle to the north.  Peaking 599 report at 0550z and still only DNB audible, strange...

Band was wide open last night/this morning and heard a lot of Asian chatter on 2MHz mostly Japanese and Korean plus one Chinese, trawlers out there somewhere.

[Exo]

Groundwave is probably the answer I think, but would appreciate comments from fellow HFU DXers.

It was probably not groundwave.

It was simply NVIS (Near Vertical Incidence Skywave) propagation, very common via the F-layer of the ionosphere.
NVIS usually doesn't extend more than about 650 km (400 miles), so perhaps the DNB was within that distance from your receiver.

See this image of the Digisonde from your nearby Canberra ionosonde, for the time interval of your report.
The squiggly solid horizontal line in the bottom left side of the graph shows the zenith reflective F layer was good for NVIS propagation in the 1.74 MHz (fmin)  to 5.670MHz (foF2)  range.


For other dates and times, see this link to the Canberra ionosonde:
https://lgdc.uml.edu/common/DIDBYearListForStation?ursiCode=CB53N