Friday, August 14, 2020

Reception of the EI1KNH beacon on 40 MHz via meteor scatter


The Irish 8-metre EI1KNH beacon on 40.013 MHz is located just to the south of Dublin and became operational in May of 2020.

Due to the nearby Dublin and Wicklow mountains, it is badly screened from the south west and even though I have a good take off in that direction, I am unable to hear it directly.

However, I tried listening for it during the Perseid meteor shower and even though I'm a bit close for meteor scatter, I thought 206 kms was far enough for it to work.

As you can see from the graphic above, I got several successful PI4 decodes on the 12th of August 2020.

The EI1KNH signal alternates between the digital PI4 mode, an identification in morse code and a carrier. The PI4 part of the transmission lasts about 24 seconds so a reasonable meteor burst is required to decode the signal. The 40 MHz band is excellent for meteor scatter so there are plenty of bursts available during major meteor showers.

The chart above shows the meteor bursts decoded on the 13th of August. Note that the signals were quite weak as they are in the range of -20dB to -26dB, below what can be heard by ear. This is probably the average signal for the duration of the 24 second PI4 transmission because I could certainly hear PI4 signals by ear at times.

Antenna... It's worth pointing out that I was only using a vertical antenna for 28 MHz for these tests. If I had a resonant antenna or a small directional beam then the results should have been even better.

If I can hear meteor burst from 206 kms away then anyone in the UK should certainly be able to hear it.

For EI1KNH, tune to 40.0122 MHz and listen on USB. For the OZ7IGY beacon in Denmark, try 40.0702 MHz USB.

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