Maybe Australia on 1629 kHz

[ChrisSmolinski]

Kilokat7 posted this waterfall he took of 1629 kHz, showing carriers from Australian MW stations at 1108z on 16 Sep 2015:



I see four carriers (he thinks maybe there is a fifth hiding on the strongest at the left), at about: 1628.925, 1629.000, 1629.015, 1628.04 kHz

I recorded I/Q data this morning centered at 1600 kHz, 250 kHz wide. I modified my software to handle 9 kHz spacing, and found I did indeed have carriers on many of those MW channels.

For example, here is 1521 kHz, used by powerhouse Saudi Arabia, which can be heard with audio here on the east coast:



Time goes down the waterfall. You can see the signal faded out. I don't display the time axis, but knowing the update rate and checking where it faded out on the image, it was about 1025z, 6:25 AM local time. Sunrise here is about half an hour later. I'm surprised that Saudi Arabia's carrier would be present well after their local sunrise, but perhaps this was them? Anyone else it could be?

I then decided to check 1629 kHz, looking for Australia. Here's the recording:



You can see five carriers faded in at around 1030z and faded around around 1100z. The frequencies are about 1628.92, 1628.98, 1628.99, 1628.01, 1628.04 kHz. My netSDR is running without the GPS reference right now, so the frequencies could be off by a few Hz.
Kilokat7 saw these carriers: 1628.925, 1629.000, 1629.015, 1628.04 kHz.  Pretty close?

[Oliver]

Very nice DX.

Attached in the "jpg" are possible transmitter locations for the observe signals.


Source: http://www.asiawaves.net/mediumwave-1600.htm#mediumwave-1629

[Kilokat7]

Nice work Chris!  These are all trans-pacific stations you're seeing carriers for, and more specifically, probably all Aussies, the 1629s for sure are.  The 1521 is likely Australia too or the New Zealand station, but I suppose Asia is possible but it wouldn't be the Saudi powerhouse at this time of day.  You'll find a bunch on 1611 too, also low powered coming from down-under land.  1548.01 usually has the best carrier strength here coming from 4QD in Emerald, QLD.  I actually had decent audio on this one earlier in the year during sunrise.  Surprising to me is that these high band down-under signals are always best on my North D-KAZ as opposed to my southwest BOGs which do better for the Aussies at the lower end of the band.  The goal now here is to confirm reception of one these low powered Aussies in the X band.  Almost had it last Wednesday morning when conditions seemed to peak.  Conditions this week have been unimpressive here, but the chase goes on!

[ChrisSmolinski]

Yeah, I didn't understand how I could be hearing 1521 from Saudi Arabia well after their local sunrise. I notice there are quite a few Chinese stations on 1521, some run half a MW or so. Possibly one of them?

I had some carriers on 1638 as well. 

Saudi Arabia is coming in fairly strong now, as expected for this time of the night.

[Kilokat7]

It's unlikely to have good props towards the South Pacific and China at the same time, at least from my experience trying to DX these signals from the midwestern US.  Run your app overnight against these signals and I bet you'll see them start to fade in around Australian sunset.