Friday, January 08, 2021

6 Watts, 1485 kHz, 2540 km

There's been a few DX tests this season, and rather by coincidence I stumbled upon another one the other day. The IRCA and MW Circle reflectors reported that Mittelwellen-Sender Joe, transmitting from Erlangen in Germany on 1485 kHz, was sending periodic 1000-Hz tones - one second on, one second off.

Now, that sounded like a nice challenge. The first evening I tested I heard the transmission right away at the KONG HQ, and a very good signal at Smøla. DX-ers in Scoland and Ireland also reported the signal. The initial enthusiasm faded a bit when I later learned that the effect was in fact 100 watts, not 6. 

What I hadn't noticed from the reflector posts was that from 17:00 to 05:00 UTC the power is 100 watts, the rest of the day 6 watts. I had been listening in the evening.

So I decided to try again, and focus on the period before Germany's sunrise. I monitored the signal from 04:58 (100 watts), and then at 05:01:35 the relatively strong signal disappeared...almost! A very faint signal was still there, and I got my 6 watts, 2540 km reception! The image below shows the weaker tones above the red line as the signal dropped.

Perseus/Jaguar recording, SDR Console playback

I chose the 540-metre Asia/Pacific beverage antenna for the reception, because its back lobe crosses western Europe. Interference mostly from SER Radio Santander.

More informasjon about Joe can be found here.

Ordinary programming may resume soon, so I don't know for how much longer it's possible to hear the tones 24h. The tone will be broadcast from Midnight to 05:00 (presumably UTC), but at what power I don't know.

I really think this 1000-Hz test should be able to travel quite far at 100 watts. The eastern shores of North America should be possible. At least worth a try.

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