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30m QRSS beacon: QRV: First reports PDF Print E-mail
Written by Hans Summers   
Monday, 25 May 2009 02:35

First reception reports

This is the first report received, at 28-Mar-04 12:03. From Peter DF3LP from Kiel, JO54AG. It shows the staircase and QRSS10 portion of the message. Reported frequency is 10,143,900Hz.


From Peter DF3LP, 28-Mar-04 13:15, showing the whole message including the DFCW section (10 second dot length).


From Peter DF3LP, 28-Mar-04 14:10, showing the signal dissappear in QSB, during the DFCW part.


The second report came from Peter DL6NL, 28-Mar-04 16:59, from near Munich JN58SG. This image shows the DFCW section (UPL part of the callsign G0UPL) in closeup.


Another from Peter DL6NL, 28-Mar-04 17:02, showing the beautifully linear staircase in closeup. Remember that this frequency shift is generated very simply using an ordinary 5mm RED LED as varicap, with reverse voltage applied from a simple digital to analogue converter consisting of a handful of resistors!


Third report, from Heinz Schnait OE5EEP, 29-Mar-04 21:04, from Austria JN67TW. Shows G0UPL in QRSS10.


Also from Heinz, 29-Mar-04 21:14. Shows G0UPL in beautifully clear DFCW, followed by the trademark "staircase" and slow hell section.


Full size piece of the above showing the staircase and Slow Hellschrieber section. This is the best image so far of the Slow Hell, which is supposed to show "G0UPL" in text. With a little imagination you can see it. In fact I doubt we will ever see better than this, since I am trying to achieve the impossible. Each "dot" of the text is transmitted at 12wpm speed. A 12wpm signal has a bandwidth of 10Hz according to the Nyquist theorem for information bandwidth. Therefore the attempted text which is supposed to fit in an 8Hz space is also a victim of Nyquist. Further tests are planned using "slower" hell since it appears the current test isn't slow enough!


Heinz noticed another interesting effect, seen here. It seems that there is a small frequency shift (sub 1Hz) during the dashes. As he says, they look "stitched" together. In the QRSS Controller the dashes are in fact made up of 3 dits. I believe the shift is due to very minor supply voltage variations due to the varying current draw when different LED's are lit on the controller (each dit is controlled by a memory location, the address of which is displayed on the LED's). I will attempt to correct this by giving the oscillator its own separate voltage regulator. Note: the trace also shows the signal dissappear in the QSB during the DFCW part.


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Last Updated on Monday, 22 December 2014 07:17
 
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