woensdag 27 juni 2018

36 dB Attenuator of PA2ZZ

I received an email of Henk  PA2ZZ. He has successfully built the 36 dB attenuator. Henk wrote that attenuator works great. He uses the attenuator for WSPR with his K3 and a MFJ-loop.
I asked Henk for photo's of the attenuator.
Here they are.

36 dB Attenuator built by Henk PA2ZZ

The Attenuator 20 dB - 10 dB  - 3 dB - 3 dB of Henk PA2ZZ

The Attenuator 20 dB - 10 dB  - 3 dB - 3 dB
Thank you, dear Henk for the beautiful pictures.

donderdag 14 juni 2018


There was enough activity on the band in the
CQ WW WPX CW contest 2018.
But not as good as last year, because of QSB.

I made 39 QSO's on 14 MHz and 2 QSO's 21 MHz.
I used S&P in all QSO's.
My antenna is an End Fed.

The conditions were to bad for the power levels, that I use to work with.
The signals were not that strong and there was QSB.

Sometimes, by the time no other station called, and finally the frequency was clear. . . the QSB kicked in.
This is obvious a way to improve your operating skills. hi.
In this contest I did not make even a single QSO with less than 360 mW.
And by times 800 mW or 3.6 W was not even enough.
The loudest signal I heard was S9 +10 dB, but I needed 360 mW to answer, in stead of the usual 36 mW. hi.

Last year I could make 2 QSO's with 3.6 mW.
Well, I did enjoy the contest.

dinsdag 24 april 2018

Russian DX 2018

I had great fun with very low power in the Russian DX contest 2018.

I made more than 30 QSO's on 14 MHz and 2 QSO's on 7 MHz.
The propagation was good, so I could reduce my power when the S-meter goes up.
I used S&P in all QSO's.
For a power of less than 360 milliwatt, I use the PA1B attenuator to reduce my power.

I very much enjoyed the QSO with RT6A.
The signal was about S9+20dB, so I could reduce to 3,6 mW.
I was very lucky, because I heard RT6A 15 minutes earlier, but 10 dB less strong.
But at that time, many stations were calling, so my modest signal could not be heard. hi.

RDXC 2018 by PA1B

zondag 25 februari 2018

UBA DX CW contest

When I came on the band on 20 m, I heard a UA3 station with an ear splitting signal of S9 + 20 dB. So my first QSO I could finish with just 8 milliwatt, using the PA1B attenuator. WOW.
Friday before the contest the contest, I repaired the support for the antenna. My simple mast was damaged by storm. It was sunny, when I went onto the roof. Just in time for the UBA DX CW contest.

My antenna is an end fed that is fed via a 300 ohm twin lead. The twin lead acts as a counterpoise and acts as an impedance transformer. The end fed is sloping down to the east.

I made 20 QRPp QSO's with 800 milliwatt or less and 14 QRP QSO's with 2, 3 or 4 Watt.
QSO's in red in the table are more than 1000 Miles per Watt QSO's
All QSO's are made with search and pounce (S&P). My CQ with 800 mW gave NO response at all. hi.
UBA  DX CW contest 2018 PA1B

woensdag 17 januari 2018

Daily changes in propagation on 472 kHz

WSPR reveals the daily changes in propagation. It is not a surprise to see that in the 472 kHz band most spots are made during the night. As you can see most spots are made in the hour of 23 UTC and 00 UTC.
EA3IW WSPR on 475 kHz with 200 milliwatt with a 4 x 15 meter loop

Click on the table to enlarge.

maandag 15 januari 2018

EA3IW WSPR on 472 kHz with 200 milliwatt

Albert EA3IW made WSPR spots on 475 kHz over a distance up to 1900 km. Albert uses a square loop of 4 x 15 meters with 2.5 mm2 Cu wire. The antenna is small relative to the wavelength. Because of this the efficiency of the antenna is low.
Calculations show that the radiated power is about 200 milliwatt.
The spots were made from 26th of December 2017 till the 6th of January 2018.

To reduce the length of the table, I only show the data of the receiving stations, that reported during all of the days that are shown in the table

The lower the calculated lowest possible power, the better the propagation. The columns at the right show the spots with the strongest signal. (10 dB over 3 columns)

EA3IW WSPR on 475 kHz with 200 milliwatt from a 4 x 15 meter loop
The WSPR signal was heard up to 1900 km.

In the table the stations are sorted by distance.
The column of 200 mW shows the spots that were just strong enough to be decoded. The column of  20 mW and 2 mW show the spots that were 10 dB stronger and 20 dB stronger. The lower the Lowest possible power the stronger the signal.

EA3IW-3 is a receiver at a distance of 100 km of the transmitter of Albert. The table shows that in 130 spots the full power of 200 mW was needed to be heard. 205 Spots could have been made with 100 mW and 5 spots even be received if they were made with 20 mW.

The spots of  EA2HB show a dynamic range of 16 dB, from 5 mW to 200 mW.

The most sensitive station is F6GEXThe one spots with the strongest signal, could have been made with 0.5 mW. Notice that 262 out of 1126 spots, received by F6GEX, could have been made with 5 mW.  The difference between the spots with 200 mW and the strongest spot (0.5 mW) is 26 dB.

The results show that it is possible to use WSPR with a low power even on 475 kHz.
The changes in propagation are best seen, when you run WSPR 24 hours a day.
Thanks to Albert, for the interesting low power results and the pictures that I received.

Click to discover how to calculate the Calculated lowest possible power.

dinsdag 2 januari 2018

Cylinder dipole

The cylinder dipole with two Monster energy drink cans and a coil is easy to build and is working fine on 15 m. With 2.5 % of a wave length, it is very small antenna, that can be easily used indoors.
Building and operating with the cylinder dipole is not as difficult as it seams. There are no critical parts or critical procedures.
I wish you good luck, but most of all to have fun.

I have writen a description on my website
about the Cylinder dipole
(Click to visit)

vrijdag 1 september 2017

Propagation in the CQ WW WPX CW contest 2017

Looking back at the CQ WW WPX CW contest of 2017, I was even surprised myself. As a milliwatt enthusiast, I often use very low power. I don't use a fixed power, but reduce my power according the S-meter reading. I reduce my power, when the signals get stronger.  The best band was the 20 meter band.

Please look at the interesting tables below. It is my pleasure to show the two tables.

At the start of the contest from QSO number 2 to 13, I could use a power of 800 mW or 360 mW to make QSO's. In the first QSO I was too eager to use 80 mW, so the QSO was not completed.
Even  a QSO that is made with 800 mW can be more than 1000 Miles per Watt QSO, when the distance is more than 800 miles.  In QSO 2 to 11 is the distance more than 800 miles.

It is interesting to see that from QSO 18 to 29 the conditions went up. So I could use 36 mW, using the 10 dB section of the PA1B 40 dB Step Attenuator (Click to visit). QSO 19 is also good for 1000 MPW.
Then the  conditions went up further. In QSO 22 and 24  I met two stations from YU with an ear splitting signal, so I reduced to 3.6 milliwatt before answering their CQ.
My FT-817 gives 360 mW on the lowest power setting. With the 20 dB attenuator section switched on, 3.6 milliwatt goes to the antenna. Hi.

QRPpp is the (not official) term that I use for a power of less than 100 mW. hi.
CQ WW WPX CW 2017 - QSO's on Saturday on 20 m - PA1B
After 40 QSO's, all on 20 meters, I went to 40 meter. These QSO's are not in the tables. The next table show the QSO's that I made on Sunday on 20 meters.

On Sunday I made most QSO's with 360 mW or 800 mW.
Both tables show that after 18:00 UTC the conditions go up and QSO's with 36 milliwatt are possible.
I could make 4 QSO's with 80 mW and 36 mW. On Sunday I could not make QSO's with less than 36 mW, because I had worked all of the very loud stations before, on Saturday.
CQ WW WPX CW 2017 - QSO's on Sunday on 20 m - PA1B

zaterdag 8 juli 2017

UN1HQ in IARU HF contest with QRPp

I just made about 25 QSO's in the IARU HF contest. The speed of the contest stations is higher than in others contests. So sometimes it's difficult to get the call right. Some signals were very strong, so I could reduce the power. I used a power from 3.6 watt down to 36 milliwatt on 14 MHz with an end fed wire. hi.

When I wanted to stop, I heard UN1HQ from Kazakhstan. The signal was S++, so I was sure that the QSO could be made with QRPp. I used a power of 360 milliwatt to answer, again and again. But he could not hear me. There were many stations answering. It was obvious that my signal was NOT the strongest, thus of course, every other station with 100 watts, or even more, goes first. It took me a long time. But suddenly after 15 or more calls, my signal was in the clear and was heard.
So I made the QSO with UN1HQ in Kazakhstan with just 360 milliwatt. WOW. Sometimes I doubted, whether I would succeed, but my perseverance pay off. hi.

zondag 25 juni 2017

It is 50 years ago today

Het is vandaag op de kop af 50 jaar geleden, dat ik op 25 juni 1967 voor het eerst de LP Sgt. Pepper's Lonely Hearts Club Band hoorde.

We waren met een groep van onze zwemclub op een langebaan wedstrijd. We hebben de wedstrijd van 2 kilometer gezwommen. Nadat we weer omgekleed waren en langs de baan zaten, klonk in eens uit de speakers van het PA systeem Sgt. Pepper's Lonely Hearts Club Band. We hebben ademloos zitten genieten van de hele LP tot en met de uitloopgroef van kant twee aan toe. De LP was kort te voren uit gekomen. In mijn herinnering heeft het nog enige tijd geduurd voor ik zelf de LP heb aangeschafd.

Het is ongelooflijk, maar de nummers op Sgt. Peppers Lonely Hearts Club Band klinken nog steeds fris, zelfs nog na 50 jaar.

Oplettende lezertjes hebben wellicht de bijzondere datum 25 juni 1967 herkend. Inderdaad dat was de dag dat 's avonds  All You Need Is Love  door ongeveer 400 miljoen mensen op 5 continenten werd bekeken in het programma Our World. Dus dat was dubbel genieten. Maar niet voor iedereen. Want toen we weer thuis waren hoorden we het nieuws over de windhoos in Tricht.

zondag 11 juni 2017

CQ WW WPX CW contest 2017

Last year I used the cylinder dipole with two Monster cans for 21 MHz.
I am very pleased with the excellent write up on the PA1B cylinder dipole
in the results of the 2016 CQWW WPX CQ contest of last year.
See My Blog post on the article.

This year I used an end fed antenna for 14 MHz, that is sloping down to the east.
In total I made 91 QSO's. I did not use a fixed power.
When the signals go up, I reduce my power.
The power that I used, varied from 3.6 watts down to 3.6 milliwatt.
All QSO's were made with the lowest possible power with search and pounce. S&P.

I started on Saturday on 14 MHz and when I stopped there were 40 QSO's in the Log.
On Sunday  morning I first made 11 QSO's on 7 MHz.
Then I went to 14 MHz to make about 40 more QSO's.

CQ WW WPX CW 2017 - Number of QSO's per power category - PA1B
QRPp   < 1 W
As a milliwatt enthusiast the emphasis of my activities lays on the use of QRPp. On 14 MHz I made 39 QSO's with a power of 360 mW and 22 QSO's with 800 mW. When the signals go up, I reduce further below 100 mW. The table shows 18 QSO's with less than 100 mW, with 2 QSO's with a power of 3.6 milliwatt.

Very low power QSO's on 14 MHz
On Saturday I started after 16:00 UTC. In the first QSO I probably was too eager to use low power, that I am not sure whether the QSO is valid. After 18:00 UTC till 20:00 UTC the signals peaked, with  6 QSO's with 36 mW and two QSO's with 3.6 milliwatt.

S-Meter reading
An important indicator for the power that I can use, is the S-meter. The signals in the  two QSO's with 3.6 milliwatt were ear splitting. To get an indication of the signal strength,  I switched in the attenuator of 20 dB. The S-meter still gave a value of S+. This means that the signal strength is  S+ plus 20 dB. Hi.

zaterdag 27 mei 2017

ARI DX contest 2017

I had great fun with low power in the ARI DX contest.
This year it was not that easy, because of QSB.
But nevertheless I made a total of 11 QSO's with 8 mW up to 800 mW.

Sometimes the QSB (fading) made it very difficult. But it's also a sport to choose the right moment to answer the CQ. I start answering before my signal peaks to make the QSO. My signal has to be also  in the clear. In QSO number 3, the signal of LY3B went up slowly, so I had to listen very carefully to work him with 8 mW. For the QSO with I7PHH I had to wait for the signal to go up, to make the QSO when my signal peaked. Hi. In the last QSO with HA8GZ there was no QSB. But when I look back in my notes on paper, I see, that I heard many stations, that I have not work because their signals faded.

Excellent Ears
I met 3 very skillful operators with excellent ears in QSO number 2, 3 and 4.
YT1A with 80 mW, LY3B with 8 mW and RW3YA with 80 mW. Well done gentleman.
I am not the strongest station on the band, but when my signal is in the clear, these skillful operators with will answer my call, what ever my power may be. Hi. It is all a matter of propagation.

The table below shows the QSO's in chronological order in blocks of one hour.
The table shows the power that I used from QSO to QSO.
ARI DX contest - 14 MHz  - PA1B
Worked DXCC's
ARI DX contest 2017 - PA1B

maandag 22 mei 2017

Helvetia contest 2017 update

I had fun in the Helvetia contest 2017 with low power.
Even though there was QSB, I still could make some beautiful QRPp QSO's.

I got a request from Panagiotis SV1GRN to write a more detailed story.
Yes, you are right, Panos. It's my pleasure to make the update. hi.

The first table shows the QSO's in chronological order.
This is very interesting, because it shows, which power I used from QSO to QSO.

I started on Saturday with just 3 QSO's. The signals were S9, S9 and S+.

When I started on Sunday, I heard HG7T with a very strong signal. S8 + 20 dB.  But then the QSB kicked in. The signal strength dropped about 10 dB and I had to use 80 mW to make the QSO. That is how it goes with QSB. hi.
In the next QSO with CT, I had to use full power and I had to repeat my serial number. hi.
Then I went to 15 meters. The band was empty.
So I went to 40 m and made a QSO with HB9MM in VD.
I decided to go back to 20 m and made 3 QSO's with 36 mW.
QSO number 8  with LY3B was exciting. The QSB reduced the signal strength, just after the QSO was completed. hi.
In the last QSO I had to QRO to 800 mW, (QRO means increase my power), before my signal was heard and the QSO was made.

Helvetia contest 2017 - QSO's in chronological order - PA1B
Worked DXCC's
Helvetia contest 2017 - PA1B

zondag 30 april 2017

CQMM DX 2017

The CQMM DX contest brought my an interesting mix of
 - DX with 5 continents with QRP and QRPp
 - Using very low power, when the S-meter peaks  - 8 mW - hi
 - Making QRPp QSO's within Europe with 800 mW or less
 - Making 1000 Miles per Watt QSO's with other continents AF, NA, SA

CQMM DX 2017 - PA1B
CQ or S&P
As a QRP and milliwatt enthusiast I reduce my power, when the conditions go up. When I work with low power, I always use search and pounce. From time to time I also called CQ with 800 mW, but without success. The reason that I could not make any QSO in this way, is probably the activity. I heard stations calling CQ for a wile and then this station would leave the frequency after a few tries. 

I did not expect to work a total of 5 continents. On Saturday and Sunday I had only worked stations from Europe (EU) in 12 QSO's. But then suddenly after 18:30 UTC the ionosphere opened up to the west and the east, so I made 6 beautiful QSO's with:
EA8/DL3ASM  (AF)K1GQ   (NA)ZW8T  (SA)VA2WA   (NA),TA7I  (AS), CN8KD  (AF)
After this run the 20 meter band was empty. hi.

8 mW QSO with YQ6A
Early in the contest, after two QSO's with 360 mW, the signal of YQ6A was very strong. An earsplitting S+ +20 dB. This is S+ through the attenuator of 20 dB. I made the QSO with 8 milliwatts by answering CQ. 

1000 Miles per Watt QSO's
Making a more than 1000 Miles per Watt QSO's is not as difficult as it seems. When you use a power of 800 mW, all QSO's over a distance of more than 800 miles will be more than 1000 Miles per Watt QSO's. Just notice, what your S-meter shows you. hi. The number of QSO's in red in the table are more than 1000 Miles per Watt QSO's.

woensdag 5 april 2017

CQMM DX coming up this weekend

This weekend there was much activity from South America, so I joined the fun in the CQMM DX in which you can work every station.

I had great fun with QRP in the CQMM DX contest in  2011,  2012  and  2013,

Look at the PA1B QRP Blog entries of the CQMM DX contest:
Blog entry of 2011.    Blog entry 2012     Blog entry 2013

In the CQMM DX contest of 2011, I was suprised by the excellent propagation, which made it possible to work with stations in South America and North America with just 1 W or 2.5 W.

My  QRP  RST  is   599 EUQ
In the CQMM DX contest a QRP station is immediately recognized by it's exchange.
My exchange is be 599 EUQ meaning continent Europe and QRP.
So as a QRP station, I immediately known that the QSO
is a 2 way QRP QSO when I receive such an exchange. hi.

CQMM DX was this weekend. I hope to meet you next year.

Rules 2017
Click for    Rules 2017   or info on the    CQMM DX website