Saturday, 14 March 2015

More meteor scatter

Another FSK441 QSO on 4 metres (70.230 MHz) today, this time with Henning OZ1JXY.

With WSJT modes you send a message for 30 seconds every minutes, and wait to see if you can hear a reply in the other 30 seconds. So you keep sending the same thing and hope you get the right reply. Sometimes you keep receiving the same message, which only confirms that the other station HAS NOT received your message.

This time it went as follows:-

At 12:26 I received OZ1JXY CQ OZ1JXY CQ
At 12:27 I started sending "JXY GM4FVM 26 26 26"
Rx 12:28 CQ OZ1JXY CQ
Rx 12:29 SQ OZ1JXY (SQ is the sort of distortion you get for CQ sometimes)
Rx 12:44  GM4FVM OZ7JXY R26 R26 GM4FVM OZ1JXY R26 R26
At 12:44 I started sending "RRRR RRRR GM4FVM (or RRRR RRRR FVM at times)"
Rx 12:46 R26 R26 GM4FVM OZ1JXY R26 R26
Rx 12:48 $M4FVM OZ1JXY P1
Rx 12:49 R6 R26  GM4FVM OZ1JXY R2 R26
Rx 12:52  73 FVM OZ1JXY 73 73
At 12:52 I started sending "73 73 73 GM4FVM"
Rx 12:55 73 FVM GZ1JXY
Rx 13:01 CQ OZ1JXY

So, I started sending my report at 12:27, but I knew that Henning had not heard it at 12:28 and 12:29. Then there was a gap when I heard nothing - maybe he had heard me, I would need to wait for the next copied message. That took another 15 minutes and then I knew that he had heard me and was also giving a 26 report. So I started sending RRRR to confirm receipt of the report at 12:44 and at 12:46 I knew that Henning still had not heard it. Also, at 12:49 he had not heard it, as he was still sending the report. But at 12:52 when I got the 73 I knew that he had heard my RRRR and the QSO was complete (though I usually send 73 too for a couple of cycles just to confirm). Then when I saw him calling CQ I know it is all over.

If you are used to other modes you will find this a bit baffling. It is just like JT65 on HF, you just keep sending your message, and you know when the other station has copied it as they change their message in sequence. It is the 15 minute period (sometimes MUCH longer) of sending reports, when I do not know if Henning has heard them, is what gets me excited. Has he either -
a) not heard ME, and it still calling CQ, or
b) has heard ME, is replying with his report, and I am not hearing HIM
That is the moment when meteor scatter comes alive for me. Have enough meteorites hit the atmoshpere, at the right place, at the right speed, at the right size?

Anyway, Henning and I keep this up over a 735km path - too short by most theories. I really appreciate his enthusiasm as it keeps me going in adverse conditions.



73
Jim

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