Saturday, February 25, 2023

5300km TEP opening at 432 MHz reported from Curacao to Argentina - 24th Feb 2023

432 MHz TEP: In a previous post, I reported on how a signal on the 432 MHz band from Brett, PJ2BR on the island of Curacao was received by Javi, LU5FF in Argentina. The propagation mode was Trans-Equatorial Propagation (TEP) and the distance was 4853kms.

After it, there was some question about if it was real? Was it a false decode of the Q65 signal? Was there an issue with the software when changing bands from 144 MHz to 432 MHz? Reports of TEP signals on the 432 MHz band are extremely rare and people are right to be cautious.

Now we have a second example of a 432 MHz opening on the 24th of February 2023. This time, we have decodes of signals on both ends as well as visual evidence of a signal in the waterfall display as well as reception of a signal that could be heard.

24th February 2023: Both Brett, PJ2BR and Diego, LW2DAF report that there was a TEP opening on the 432 MHz band on the 24th of Feb 2023. The time was around 00:40 UTC which was about 8-9pm local time on the 23rd of Feb for the parties involved which is around the peak time for evening TEP openings.

On this occasion, there were decodes at both ends and the distance was around 5310kms.

I have some images below so that we have a record of this opening.

The image above is a screenshot from the PSK Reporter website showing the 432 MHz path reported on the site.

This image above is from a screenshot from PJ2BR and shows the left hand side of the WSJT-X software showing reception of LW2DAF with a signal of -18dB. You can see the mode used was Q65-30B. Note that I edited the image to make it smaller vertically to remove the blank area.

This image above is the right hand side of the screenshot. It shows the reception of LW2DAF at -18dB and then PJ2BR sending the report.

Now from Argentina. This image above shows a very weak signal in the waterfall at around 700 Hz.

This image above shows LW2DAF decoding the signal from PJ2BR with a peak of -12dB. This is significant because it was now at a level where the signal might be heard.

Diego, LW2DAF said that he saw and heard the signal on 432 MHz.

This video clip above from LW2DAF on Twitter shows the reception of the signal.

This screenshot from the video shows the Kenwood radio used by LW2DAF on 432.174 MHz.

Equipment: For this TEP test, PJ2BR was using a Kenwood TS2000 with 100-watts from a Mirage amplifier.

The antenna was shown above was a M2 22-element horizontal Yagi.

LW2DAF was using 50-watts into a horizontally polarised 18-element LFA Yagi about 21m above ground level.

Analysis: As Deigo LW2DAF noted, a visual and audible TEP signal on the 432 MHz band has now been verified. It would seem that it is now only a matter of time before someone from Argentina or Brazil completes a 432 MHz contact with someone in the Caribbean using Trans-Equatorial Propagation.

From my understanding of TEP, it's Class II as shown above as an effective duct appears on the Geomagnetic Equator.

At 432 MHz, location, distance and being at right angles to the Geomagnetic Equator are even more important than they are at 432 MHz. As Diego notes, more stations on 432 MHz are needed to try this path at 70cms. It just needs two stations to be in an optimum location and for the conditions to be right.

Link: For other examples of long distance openings on the 70cms band, see my 432 MHz page.

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