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.

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

    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

  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

    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