zaterdag 30 november 2019

Mark DL6YYM uses WSPR with 1 miiliwatt

I received a very interesting email from Mark DL6YYM about his WSPR adventures first with 20 milliwat and later with 1 milliwatt. Mark makes 1 milliwatt by using an attenuator of 13 dB behind the beacon of 20 milliwatt. Thank you for the very nice info, dear Mark.

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Hi Dear Bert,

From time to time I visit your nice blog. Some weeks ago I read from QRPPP WSPR on your site. 

In the next step I found a very nice project from Alexander RA9YER

It's based on ARDUINO and SI5351 

From the SI5351 come about 14-15 dBm output 8 Khz - 160 MHz.
I set the frequency in the script. The complete investment is about 25,00 €.

To the left - Powermeter and Attenuator In front - SI5351 and Arduino - DL6YYM 

Last week I make the first tests on different bands.
Yesterday afternoon I put my attenuator 10 + 3 dB (your idea 8-)) between the SI5351 and my antenne.
My output in the shack ==> 30m Aircell 7 ==> R8 vertical.

In the table below is the result on 40m :-D

DL6YYM with WSPR with 1 milliwatt on 7 MHz
It's a nice fun but CW is better ;-)
But I hope I can make a stand alone TX in the next time.
best wishes es

vy 72 & 73 de Mark DL6YYM nr Leipzig DLFF-050

More info on the DL6YYM Website.

DL-QRP-AG Nr.: 3336 // RU-QRP-Club Nr.: 331 // RTC Nr.: 406 // AGCW-DL Nr.:  3851

amateur radio parts

Powermeter and attenuator (set to 13 dB - DL6YYM 

zaterdag 27 juli 2019

RO2E with 8 milliwatt

In the last batch of eQSL's I recieved a conformation for a CW contest QSO with RO2E with just 8 milliwatt. The propagation to the east was very good at that moment and RO2E was booming in.
So I reduced the power to 8 milliwatt, before answering the CQ. I use an end fed.

The distance to RO2E is 1300 miles, so with 8 milliwatt this gives 162500 miles/watt. hi.
Thanks to the Excellent Ears of the Orel contest club.

RO2E over 1300 miles with 8 mW gives 162500 Miles/Watt

zaterdag 20 april 2019

KX4AZ WSPR with 10 milliwatt

Last week I received a very nice e-mail from Bruce KX4AZ. He searched the net with "WSPR 10 milliwatt" and found the page on "WSPR with 10 milliwatt" on my PA1B website. hi.

Bruce KX4AZ is a operator that makes very interesting WSPR spots with just 10 milliwatt.

Believe it or not. A WSPR station with 10 mW will be spotted, but ONLY when the propagation is very good. Please study the diagrams below, to convince your self.

Lowest Possible Power diagram
To show the propagation, I developed the Lowest Possible Power diagram. You can immediately see how good or how lousy the propagation is, for each individual spot.
The better the propagation, the lower the Lowest Possible Power.

2019-04-19 I visited the WSPR old database and collected some interesting spots.

Time slot 1 
In the time slot of  17:46 UTC ND7M spotted 7 stations.
4 stations with 5 W, 1 station with 1 W, W6CLB with 100 mW and Bruce KX4AZ with 10 mW.
Luckily for Bruce, the propagation from the stations with 5 W and 1 W, to ND7M was not that good, so Bruce's signal was not over shouted by the 1 W and 5 W signals. Something that can easily happen, even with a power of 100 mW.
In the first diagram Bruce was spotted by ND7M with a SNR of -29 dB. It's the spot in yellow, on the line of -29 dB and the line of 10 mW. So in this time slot Bruce needed the full 10 mW. Hi.
In this time slot the best propagation is shown by the spot of W6CLB with 100 mW and a SNR of  -15 dB. This spot has a Lowest Possible Power of 5 mW. Thus about 3 dB better than the spot of Bruce.
KX4AZ with 10 milliwatt spotted by ND7M over 3100 km
Time slot 2
The second diagram shows the next spot of KX4AZ by ND7M
In this time slot the signals of W6CLB with 100 mW has a SNR of -12 dB.
The signal of KX4AZ has a SNR of -22 dB. please notice that both spots, show the same propagation, which is very good. The Lowest Possible Power of both stations is 2 mW. The signal of Bruce is even about 7 dB stronger, than in the first time slot.

KX4AZ with 10 milliwatt spotted by ND7M over 3100 km

woensdag 3 april 2019

eQSLs for 80 mW

It's great fun to make CW contest QSO's with very low power.
When the S-meter goes up, I lower my power accordingly.

In the last batch of eQSL's I found a 3 eQSL's that confirmed QSO with 80 mW.

  EA7TH   1151 Miles & 80 milliwatt gives 14390 Miles/watt

UB3A  1302 Miles and 80 milliwatt gives 16270 Miles/watt

YO3APJ     1088 Miles and 80 milliwatt gives 13600 Miles/watt

zaterdag 16 maart 2019


Onze kleindochter heeft vanmorgen op Scouting een vlieger gemaakt, van een stevig stuk plastic en een paar stokjes. Omdat het plakband op sommige punten al losliet, hebben we de bevestigingspunten verstevigd met breed en sterk plakband.
Het dwarsstokje verbetert de "vliegvaardigheid" enorm
Na een paar half gelukte vliegpogingen, hebben we een derde (dwars)stokje geplaatst, om de vlieger "open" te houden. Dit was een onmiddelijk succes.
De vlieger kon nu uit de hand opgelaten worden, zonder vrijwel onmiddelijk dubbel te vouwen.

In de lucht
De sterk wisselende wind vraagt echter heel wat vaardigheid van de "vliegenier".

Onverwachte duikvlucht
Het lukte opa om de vlieger, in sterk wisselde wind, tot zo'n 6 meter boven de grond, te laten opstijgen. Hi.

vrijdag 15 februari 2019

PA0K spotted by W4HOD

Here is an other analysis of a spot made by Paul PA0K on February 1st 2019. He was spotted by W4HOD over 7200 km with a SNR of -23 dB. This spot reveals, that the propagation, between Paul's station and W4HOD, was not good, at that moment. But never the less, Paul's signal was received, with a bit of luck, as we will see.

Spots sorted by propagation
The table shows all the stations, that were received by W4HOD in Alabama in the time slot of 13:12 UTC. I have sorted the spots by propagation, using the Lowest Possible Power (LPP). The lower the Lowest Possible Power, the better the propagation. The propagation to W4HOD was good, or even very good, for the first 9 stations in the table. This are the stations that have been spotted with a LPP of 50 milliwatt or less.

The propagation from Paul's QTH to W4HOD was poor with a LPP of 500 mW.

W4HOD also received PA1OSF over a distance of  7200 km from The Netherlands. PA1OSF was received with a LPP of 20 mW. The propagation from PA1OSF was 17 dB better than from PA0K. The distance between PA0K and PA1OSF is 71 km (44 mi). The difference can be caused by propagation, antenna direction and the antenna.

Spots received by W4HOD
The propagation between VE3KAE and W4HOD shows the best propagation with a LPP (lowest possible power) of 0.5 mW. Luckely for Paul, VE3KAE used 100 mW. Believe it or not, if VE3KAE had used 5 W, in stead of 100 mW, this signal would have used a large part of the dynamic range of the receiver of W4HOD and Paul's signal would probably not have been spotted.

I noticed that W4HOD received twice the number of spots compared other stations. In an analysis of frequencies that were used, I saw, that W4HOD can receive two signals a few Hz apart. This suggests that there are more than one WSPR receiver or detector at W4HOD.

The dynamic range of the SNR is +1 -(-26) = 27 dB.
The dynamic range in LPP is 1000/0.5 =2000, which is 33 dB.

woensdag 13 februari 2019

PA0K spotted by EU2AAH

Here is a further analysis of spots made by Paul PA0K on February 1st 2019. The propagation was not that good. But Paul's signal was earsplitting into Belarus. He was spotted by EU2AAH over 1500 km with a SNR of -3 dB. This spot reveals, that the propagation, between Paul's station and EU2AAH, was very good, at that moment.

Lowest Possible Power diagram
I developed the Lowest Possible Power diagram, to compare spots, that are made with different power. The Lowest Possible Power diagram shows instantly, how good the propagation is.
A spot is placed on the diagonal line of the power, that is used by the transmitting station. The height of the spot in the diagram is determined by the SNR of that spot. You can read the Lowest Possible Power of a spot, on the horizontal axis.
The better the propagation, the lower the value of the Lowest Possible Power.

Spots by EU2AAH
This diagram shows all stations, that were spotted by EU2AAH in the time slot of 13:52 UTC. It can be seen instantly that 3 station were received with good propagation and 2 with very good propagation. The letter gives the DXCC of the spot.
Paul's signal (PA0K) was the strongest signal, with a SNR of -3 dB. The arrow to the horizontal axis points to a  Lowest Possible Power of 5 milliwatt. The LPP of 5 mW is in the area of  very good propagation.
The propagation between F6KOP (F in the diagram) and EU2AAH is even better, with a LPP (lowest possible power) of 2 mW.

Lowest Possible Power diagram of spots received by EU2AAH
The line of 10 milliwatt
The dashed line in the LPP diagram is the diagonal line for a power of 10 milliwatt. PA0K and F6KOP could also be spotted if they would use a power of 10 milliwatt. If PA0K would reduce from 2 Watt to 10 milliwatt, his signal would be received with a SNR of -26 dB. F6KOP would be received with a SNR of -22 dB with a power of 10 milliwatt.

Table of spots received by EU2AAH
This is the table, that I used to draw the LPP diagram.

zaterdag 9 februari 2019

Very Good Propagation with WSPR

With this table you can immediately judge the propagation from your WSPR spots.
For example, when your 1 Watt WSPR signal is spotted with a SNR of  -9 dB,
or higher, the propagation is very good.
If you notice that the propagation is very good, consider to reduce your power.

Judge the Propagation with your WSPR signal
A WSPR beacon with a power of 10 milliwatt, will ONLY be spotted, when the propagation is very good. WSPR with 10 milliwatt can be compared with a CW beacon with a power of  200 milliwatt.

donderdag 7 februari 2019

Good propagation for PA0K

My fellow Blogger Paul (PA0K) used WSPR for an hour, on on February 1st 2019. His 2 watt WSPR signal has been spotted 31 times, in one hour. For Paul the most interesting spot was made by W4HOD, over a distance of 7200 km. In many spots you can see, that the propagation was not that good.

I noticed an other very interesting spot, that was made by EU2AAH over 1500 km. Paul's signal was earsplitting into Belarus. When I made an analysis of the spots, this spot came up, as the spot with the best propagation. This spot reveals, that the propagation, between Paul station and EU2AAH, was very good, on that moment.
To compare the propagation, I use  the Lowest Possible Power, that I calculate from the used power and the SNR. A Lowest Possible power of 5 mW, can be compared to 100 mW with CW or 2 watt with SSB. Thus very good propagation.

PA0K - WSPR spots with 2 watt on 20 meter
The table also shows that the propagation was good to TF3GZ on Iceland, R3TJP in Russia and EA8BFK on the Canary Islands.

The second table shows the propagation, in the successive time slots, in which Paul was transmitting.
Notice that, the better the propagation, the lower the Lowest Possible Power.

The spots made by R3TJP start with good propagation with a Lowest Possible Power (LPP) of 50 mW. In time slot 13:30 utc the signal is drops 10 dB with a LPP of 500 mW. In the last time slot the signal is up again to good propagation. LPP 50 mW.

The signal received by EA8BFK is first strong, with a LPP of 20 mW, but later the signal gets a bit weaker.

The signal that is received by W4HOD, shows a LPP of 500 mW in the first two time slots. In the time slot of 13:30 UTC the SNR is -29 dB, so all the power is needed to be spotted. Hi.

PA0K with WSPR on 20 mtr in 5 time slots
Thanks Paul, for the interesting spots.
Paul placed the tables, that I sent him on his Blog.