woensdag 13 juli 2011

IARU HF 2011 Lowest Possible Power

I did not use a fixed power, in the IARU HF World Championship, but I used the Lowest Possible Power in nearly every QSO.
After a destructive mismatch, a few months ago, the power of my FT-817 is reduced. So now the power can be adjusted to: 360 mW, 800 mW, 1.8 W or 2.7 W. The antenna is an Inverted Vee.
But notice that even with a power of 2.7 W, every QSO with Canada or the USA is good for more than 1000 Miles per Watt.
The stronger the received signal, the lower the power that I use.
When a station can hear me, but can not copy, I immediately double my power which is a step of 3 dB.
For a power lower than 360 mW, I use homebrew attenuators.
Click for info on attenuators.
Because I use the Lowest Possible Power in ech QSO, I search and pounce.
It's hard work, in which you need perseverence and patience.

From my contest notes on paper:
I worked YR1C with 36 mW on 14 MHz. His signal was very strong, still S+ through the 10 dB attenuator. After first working 5 other stations, he heard my call and immediately responded with my call (not correct) and my report. I corrected my call and gave my report. Now the frequecy was clear, so he received my signal with a good readability and the QSO could be completed easily.

An other station with a very strong signal was R3HQ, which I received with S+ + 20 dB. I first tried 8 mW, but I worked him with 18 mW.

The lowest power I used in this contest, was in a QSO with RU1A. I received his signal with S++ through the attenuator of 20 dB. I met the team of RU1A before with exteme low power. I knew that this station has Excellent Ears. So I went for the really lowest power. I started with 3.6 mW. They were very busy answering other stations which I could hear, but also that I could not hear. In the proces of answering the CQ's, I already increased to 8 mW and to 18 mW, after question marks, that were not for me. Then after 10 or more calls, I realised, that the signal that I received, was so ear shattering strong, that 3.6 mW could work. So I went back to 3.6 mW. By the 15th time I called, my signal was heard, but not copied, so I increased to 8 mW and made the QSO.

An other station with Excellent Ears is VY2ZM,
which I worked with only 360 mW. Outstanding!

Working with low power is not so difficult.
YU8HQ was S+ on 10 meters, so all I did was reduce to 360 mW.
S50HQ had so many callers, that he could not hear me with 800 mW. When I came back later, the frequency was clear and the QSO was made with 360 mW. Both QSO's are good for more than 1000 MPW.


In the contest 125 QSO's on 5 bands are made.
In this survey you can see the power that was used for each QSO, for each band.
Please notice that on 40 m 81% of the QSO's were made with 800 mW or less. On 20 m 54% of the QSO's.
The distrubution the number of QSO's over the power catagories is entirely determined by the propagation.

More than 1000 Miles per Watt QSO's

71 out of 125 QSO's (57%) are more than 1000 Miles per Watt QSO's.
Even with 2.7 W it's possible to break through the 1000 MPW boundary.
The most spectaculair results are found on the 20 m band.
* In every contest it's still possible to work with low power and make more than 1000 Miles per watt QSO's.

It is great to participate in a contest with "World Wide" activity.
This activity is almost as important as the propagation.
I met stations with Excellent Ears and many stations with very good operators.
As you can see, I had great fun with low power.
Thanks to all these fine operators.

5 opmerkingen:

  1. Hallo Bert, het ziet er allemaal weer prachtig uit. Er is geen enkele reden te bedenken om met QRO te werken. 73 Paul

  2. Geweldig stukje Bert, alleen op deze manier QRP werken en analyseren is al een hobby op zich. Denk je dat het met SSB ook succes zou hebben? Ik zie dat je alleen CW gedaan hebt. Knap VY met 360mW, zijn er niet veel die dat nadoen. Ik mis even wat voor een antenne je gebruikt? 73, Bas

  3. Bert that is just amazing!! Getting into North America with only 360mW's..wow. I find it give the contest a breath of fresh air going for the lowest power. Im thinking that contest should also have an entry for QRPp power.

  4. Bert,

    Weer erg leuk en dit met qrpp en een inverted V.

    Begrijp ik het goed dat je eindtrap van de ft817 niet meer in orde is?

    73, Tjeerd