donderdag 26 februari 2015

WSPR with 5 watts

From time to time I visit the WSPR database to look for interesting spots that are made with very low power.
But this time I was wondering, if there are many operators, that use much more than 5 watts.

To my surprise only a few operators used 10 to 1000 watts.


The WSPR spots are collected on 10 meters in 24 hours.

I chose 24 hours to include all operators, that skip from band to band, following the changes in propagation, in all the parts of the world.

The interval lasted from 9:02 utc on the 20th of February to 9:00 utc on the 21st.

The choice for the band was not made consciously.
I selected the 10 meter band, because in the days before, I made an analysis of spots on 10 meters.

Power categories
The table shows the number of spots that were made in each power category from
1 mW to 5000 mW  (5 W) (QRP)
and the number of spots that were made with 10 to 1000 watts.

Results
In the power categories from 1 milliwatt to 5 watts, most spots were made in the category of 5 watts.
This is 42 % of all spots.
I am pleased to see that many operators use  200 mW*  or  500 mW.
200 mW in 15% of all spots and 500 mW in 16% of all spots.
It's good to see that only a few operators use 10 W to 1000 W.  (See also "one kW")

One kW
Not all spots that show up in the database with 1000 W, are actually made with 1000 W.
In the past I have seen WSPR spots from an operator that used a homebrew QRP rig, that he proudly showed on QRZ. The setting in WSPR was wrong. He discovered the mistake.
Later spots showed a power of 2 watts in stead of 1000 watts. hi.

* Did you know that 200 mW in WSPR can be compared with 4 Watts in CW and 80 Watts in SSB.
    So with 200 mW in WSPR you can see where you 4 watt CW signal could be heard. hi.

4 opmerkingen:

  1. Interesting article Bert. I think indeed most of the stations are not really using a lot of power but that the settings are wrong. Though it is still a misunderstanding that a transmitter can not go below the low power settings. Many do not understand you can change it with the volme control. 73, Bas

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    1. hello Bas, Thanks for the comment. Good idea to reduce the power, by reducing the audio signal. How do you meassure the transmitted power? 73, Bert

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  2. NIce analysis Bert. I usually run WSPR with 1 watt here. Have been on 160 meter WSPR the last few days. Have received a 3 stations from the UK, two at 5w and one at 20w. The furthest my 1 watt has been heard is VE6 at 2994km from my QTH in Lousiana. Using a full size dipole for 160m.
    73, Dave K5MQ

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    1. Hello Dave, thanks for the nice comment.
      It's fun to make such an analysis.
      I had a look at the WSPR database and noticed that your signals on 160 m were very strong with a SNR of over 0 dB. So I made an analysis for the station that spotted you.
      It's my pleasure. hi. 73, Bert

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