experiments 2017

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New experiments in 2017 with my 50 cm dish and DL0SHF

In may 2017 I was visiting CAMRAS and I took my DL0SHF 10 GHz setup with me for demonstration

My very small dish in front of the 25 Mtr dish from CAMRAS

Next to my visit at CAMRAS I setup my system and tried to receive DL0SHF beacon,
I found the beacon but due to the weather the demo was not very convincing.
Temperature outside was almost 30 degrees and I was standing full in the sunshine
 so looking on my SDR screen on my laptop was almost impossible.
After a few hours I decided to put the system down again because my laptop was almost boiling.
Strange that it even survived.

 

I still wanted to do some measurements on DL0SHF so I decided to set it up the next day at my home QTH for some tests.

Outside temperature was still hot, but I had enough opportunities to put parts of my system into the shade.

I started with adjusting my antenna using the sun and solar noise, then I turned the dish to the moon and looked for DL0SHF.

It always takes some time to find the DL0SHF signal when its transmitting normal (low) power (50 Watt)

After a while I found the beacon and signal seemed a bit low with very much QSB.

Later that day signal improved a bit to max 7 dB above noise in 12 Hz RBW

 

The CW beacon 5 dB above noise in 12 Hz RBW, audio signal was just audible but too weak to copy

Since my last experiments the digital mode from DL0SHF changed from JT4 to QRB-D so I had to install the new WSJT-X software and first learn to use it befor I could try and decode the Dl0SHF signals.

I recorded the received signals and tried to decode the signals the next day, after some fine tuning on time and RX frequency I succeeded in the decode.

I made a test with Charlie G3WDG to see if I would be able to copy his CW signal.

His CW signal was audible and sometimes I could copy his signal.

He did send me some unknown information which he later said it was A TMO report. I was almost convinced I copied a M several times so I told him I copied an M but that it was very weak and difficult. He then confirmed that it was correct.

The QRA-D signals from Charlie also decoded after the recording and that worked also very well.

A test with WA3LBI failed probably because he was using CP as polarisation causing 3 dB extra losses,
pity otherwise it should have been possible to detect his signal

Lessons learned:

It is possible to copy the CW signal from G3WDG (100 W in a 3 Mtr dish)


I need to lock my down converter LO signal because drift was too much to receive
the QRA-D signals without further frequency correction during transmission.

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