My low power LF radio signal is received in Germany

🔘 Almost 11 years 🗓 have passed since I last used my low-power transmitter power amplifier ( see 08.05.2013 ) based on the TDA2030 class AB audio 🔉 amplifier i.c. ( see 22.02.2013 ). Since then several data 💾 transmission modes, e.g., FST4W,  have become popular among radio amateurs who are active transmitting on the LF 2190m/136KHz 〰 ( longwave ) 📻 band. I also have high power transmitting equipment for that frequency band. However I wanted to conduct a simple test by transmitting a very low power beacon signal using FST4W to determine at what distance it might be received.

My setup for the test was the phasing exciter ( see 02.11.2017 ) as the signal source driving the low power amplifier. The antenna 🗼 was my usual one for the 2190m band; a 47m  long x 13.5m tall base and end-loaded inverted 'L' ( Ꞁ ) ;  see 19.02.2010 et al.  The transmit frequency ∿ was 136.13KHz, transmitter output power only 3.5 watts, ( similar to the power consumption of a small LED lamp 💡 ), and beacon transmission, consisting of my callsign, location and power level, sent at 5 minute intervals.

Equipment used for the low power test on 2190m band

I began sending beacon transmissions during the evening of  21.01.2024. Previously, during the tests on 8 May 2013, ( albeit using a different mode ), the reception distance had been only 17 kms. I was doubtful if anyone beyond that range would receive my signal. So I was very surprised, when, at 2120 utc 🕤, a reception report was posted 📮 on wspr rocks  ☁ that my beacon signal had been received 📶  near Chemnitz in Germany, at a distance of 582 kms. Incredible and amazing 😀 !

 

LF = Low Frequency.

135.7-137.8KHz ( 2190m band ) is the lowest frequency band allocated to radio amateurs.   

Poland now on the 4 metre band

A new band, 70.1 - 70.3MHz, was officially released to radio amateurs in Poland at 00:00CET today. I have been prepared for this moment for the last 5 years, and was ready and waiting. I made radio contacts using morse code, voice and data; the latter being in FSK441 mode using meteor-scatter with Enrico, callsign IK0BZY, in Italy at a distance of 1295 kms, as can be seen in the partial screen capture from WSJT9.

Meteor scatter using the Quadrantids

The Quadrantids meteor shower, which appears to come from the direction of  the old star constellation of Quadrans Muralis near the Pole Star, has just intersected with the earth, as it does every year on the 4th January. I used the ionised trails produced as individual meteors burnt up in the earth's atmosphere to reflect my 50MHz radio transmissions to make contact with other radio amateurs in Denmark, Slovenia, England and the Netherlands by exchanging short, ( for obvious reasons ), text messages with them. The data transmission mode is called WSJT/JT6M, and I used the 500 watt amplifier featured on 25th January and 12th May 2010.
The screen shot shows one of Dick's, ( callsign G1CWP ), signals which I received during my contact with him in West Sussex, in the UK at a distance of 1451kms from me. The burst of signal has the characteristic profile of having been reflected by a meteor trail with its steeply rising leading edge as the trail quickly forms and peaks in intensity, followed by a more gradually falling trailing edge as the intensity subsides until the event is over.
I try to participate in all the major meteor showers during the course of a year; Quadrantids ( January), Lyrids ( April ), Perseids ( August ), Orionids ( October ), Leonids ( November ) and Geminids ( December ).