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In March 2018 I started an experiment to measure the QRP NVIS beacon on 80 meter band from PA0RYL
Some data of the beacon
I wanted to measure the signal to noise ratio and tried to search for ways to get this done.
I found some software from G4JNT for this but after a while I
found that with the very low S/N ratio
I was using a Perseus receiver for receiving the beacon and I
found the function Mkrlog which generates a logfile of the selected markers.
With the marker.log file I have the measurements from the beacon available.
I have put a marker on the beacon, and a few markers around the signal to measure the noise level.
The data is then used in Excel to create a graphic picture of
I measure each 5 seconds the power level received at 3
During a 24 hour period I make 17.280 measurements.
The beacon on my Perseus screen
The receive antenna is at my home QTH in Haselunne, Germany; locator JO32sq
For receive I use an partial home made active loop antenna,
The amplifier is designed and build by LZ1AQ : http://active-antenna.eu/
I started the measurements using a Resolution Bandwidth of 1
Hz, later I increased this to 1,9 Hz because the beacon fell of the marker,
probably my receiver frequency drifted due to temperature drift. Some days after
I decreased it to 0,5 Hz, the lowest RBW that can be selected in the Perseus
software I use.
If you read this, please do not transmit on the frequency of the beacon because it will influence the measurements.
Frequency drift of the Perseus
I tried to get to a quote for the 80 MHz reference oscillator from Wenzel but found this impossible to get.
I then considered a modification of the
existing LO by putting a small temperature heater on top of the existing
The first impression of this modification is that it works out fine.
My receive and logging system
The receiver is a modified Perseus with improved frequency
Each day I copy the logfile from the mini PC to my network hard disk, then the data can be used in Excel to make the graphs
The first result looked like this, it is a measurement from 27-3-2018 from 18 UTC until 21.36 UTC
The same measurement but then with small dot's
Here I added a trendline, giving an average of 100 measurements
This will be the format how I want to publish my measuring results
For the results of my measurements take a look at the pages below