dinsdag 26 juli 2016

Stefano IZ1OQU makes SSB QSO's with 5 mW

Stefano IZ1OQU 5 mW SSB
with light weight VHFantenne
Hi Bert,
One year passed since our last email and now I write to tell you some recent news about my experiences with power attenuators in QRPp.
Last Sunday, during the Italian Apulia Contest VHF on 2 meters, I made 19 QSO's.
11 QSO's were completed with 5 mW, 4 with 50 mW and 4 with 500 mW. 
I never needed to repeat my callsign. No propagation, no e-sporadic: just directs. 
The best QSO was with a French station over 312 km, good for 62.400 kms per watt
My operating location was 500 m asl, with good opening to the sea and the French coast. I'm forgetting to say... That it was SSB!

The antenna is a personal design, low weight very easy to use on portable: two rectangles vertically linked to each other, with nice gain and good front/side. You can see it on my qrz.com. But I attach a photo for your comfort.

What an unbelievable experience! The first time with 5 mW drove me crazy. Surely VHF offers big chances to play with micro-powers, thank to big-gain antennas both on tx and rx sides, and global low power absorption. It is a test that I want to repeat as soon as possible, looking for DX.

Every time I think back to the day that I found your website: my life changed and my passion for QRPp now flies on golden wings. Thank you again, my friend.

Best regards
'73 de IZ1OQU Stefano

dinsdag 12 juli 2016

Tiny frogs

Frog  -  1 cm  -  0,4 inches
Today my wife discovered two cute tiny frogs in the garden in front of the house. They were not able to jump to a height of 6 inches (15 cm) to escape from the tile floor to the actual garden, so they could take cover, under need the plants. So I helped them both a little to reach the garden.


zondag 26 juni 2016

PA1B Attenuator

I developed attenuators that very accurate and fast to operate. In order to get the best power distribution, the attenuator section with the lowest attenuation is placed in front. I use these attenuators in very low power CW QSO's.

PA1B Fast and accurate power attenuator for CW QSO's
Line up of the sections
While testing and making measurements with 5 watts, I noticed that the attenuator section of 20 dB gets warm with in 10 or 20 seconds. So I changed the line up of the sections. By placing the attenuator section of 3 dB  in front, this sections will dissipate half of the input power. This line up and the choice of an attenuation, makes it possible to get an attenuation of 10 dB, with the sections of 3 dB and 7 dB switched IN. An extra 10 dB gives an attenuation of 20 dB.

10 dB = 3 dB + 7 dB 
20 dB = 3 dB + 7 dB + 10 dB

donderdag 7 april 2016

Cylinder dipoles in the UBA CW 2016

In this UBA CW contest I experimented with  the new built Booster cylinder dipole.

The Booster antenna is called Booster, because each cylinder is made out of 4 Energy Booster cans, that are cut open and bolted together. The length of the cylinders is 22 cm (9") and the wingspan of the antenna is 55 cm (22") The booster is hanging in the dormer window at the second floor. The coil is wound on a 110 mm PVC tube and has 15 turns. The Booster resonates on 10 MHz.
The Booster - One cylinder is made of 4 cut open cans - PA1B
It took my a long time to discover the right setting of the tuner for the Booster on 20 m. At first I could not get a good matching at all on 20 m. The SWR was too high. At the end of the contest, I discovered the right setting for the tuner to get a SWR of 1:1  This is the setting that I always use on 10 m, with the inverted Vee. hi.

The Booster - Wing span 22" - PA1B
The table below shows the QSO's in chronological order.

Booster (22") on 20 m 
The table shows that in the first 5 QSO's, I used the Booster on 20 m. The Booster is longer than the Monster, so I expected much of the Booster on 20 m. But I could not get a SWR of 1:1. After the first 4 QSO's, I made an extra tap on the center of the coil. By using this extra tap, I connected the twin lead connectors just ONE turn apart. The SWR was now slightly better but not 1:1.


Taps at the center  - ONE turn apart - Click to enlarge
Monster (15") on 20 m
After 5 QSO's, I was a bit disappointed. Just to make some QSO's, I decided to switch the shorter Monster energy can antenna, which is located in the the shack, also on 20 m . This antenna is easy to match. I could easily make two QSO's with UA.

Booster on 40 m
On Sunday morning I went to 40 m. I started with the twin lead two turns apart.  I ended up with the twin lead connectors ONE turn apart to get a SWR of 1:1 

Monster on 15 m
The monster is doing fine on 15 m. A total of 8 QSO's were made on 15 m. The signals in QSO number 14 were very strong so I reduced to 800 mW.
QSO number 16 was with R0AA over a distance of 5200 km and was very easy to do. Read the details of the  QSO with R0AA >>  Click

Booster again on 20 m
My experimenting payed off. I found out by desperately playing around with the tuner, that I had to use a very strange setting of the tuner to get a SWR of 1:1   - Finally I got the Booster working on 20 m. With this setting the last two QSO's were easily made. hi.

UBA CW - Booster - Monster - PA1B
Wat een gein
De blikjes komen van de straat. Ik drink het niet zelf.
 Energy Booster  is verkrijgbaar bij Trekpleister voor 39 Eurocent.

donderdag 24 maart 2016

Contest QSO's with the cylinder dipole

Is it really THAT simple?
The cylinder dipole has proven to be a indoor HF-antenna with the size of a VHF/UHF-antenna.  The cylinder dipole with Monster energy cans is working fine on 15 m.

Build  - Work  -  Analyse

This table gives an inside on the number of CW contest QSO's that I made with cylinder dipoles per band and per contest. In the table, QSO means a single QSO outside a contest. All QSO's were made with 4 W or less.

Most of the QSO's were made with the cylinder dipole with two Monster cans. I noticed that there is NO sharp boundary, but the the Monster seem to work better on 21 MHz than on 14 MHz.
It is not easy to compare antennas on different bands or in different contests, because the propagation has much more influence than the used frequency.

Number of QSO's per band with Cylinder Dipoles  -  PA1B
Easy to build indoor antenna
The Monster cylinder dipole, made of two Monster energy cans of 500 ml is a good, easy to build indoor antenna for 15 m, but also works on 10 m and 20 m. If you want to get acquaint with the indoor cylinder dipole, I suggest to build the cylinder dipole with Monster cans and a coil with 9 turns on a coil former of 80 mm. The cylinder dipole is fed on two taps at the center of the coil that are ONE turn apart.

More construction info here Click

vrijdag 18 maart 2016

Transmission of SAQ

I never heard the transmission of SAQ on 17.2 kHz CW my self on the air. So last December I wanted to install my active loop antenna with 12 turns and a the frequency converter to listen, but . . . I was to late. It would take hours to figure out, how to connect the circuits, that were last used, years ago. I thought that I had all day to prepare, on the 24th of December. But when I looked it up, on internet, I noticed that the transmission would start within 15 minutes. hi.
I immediately decided to follow the transmission on internet and I liked it very much. I watched the live stream. The live stream shows what is happening at the machine. You can see the operators in their blue shirts. At 7:47 utc I saw the CW operator take his place behind the key. You could hear that the text  vvv de SAQ now was given by hand. 
When I started to watch there were already 66 persons watching. At the end of the transmission 119 persons were watching.
I sharpened my pencil and wrote down the text. I enjoyed it very much. I like the live stream and just taking the Morse code by hand behind the computer in the shack. hi.

The machine at SAQ      In the shack of PA1B
Thanks to the SAQ team for the interesting transmission.

Up date
SAQ is special station from Sweden which operates on 17.2 kHz. The power is generated by a generator. Please visit www.alexander.n.se for info.

Here is the video of the transmission that I followed.
https://www.youtube.com/watch?v=cMgIFo7SQFU
In the video at 5:40  vvvv vvvv de SAQ SAQ starts, utomatically keyed, until 16:53
At 17:00 the CW operator takes over. 

donderdag 17 maart 2016

Cylinder dipole construction


Constructing a cylinder dipole
The cylinder dipole consist of two open aluminium cylinders and a coil. The coil is connected between the cylinders and is hanging below the cylinders. I constructed my first cylinder dipoles from aluminium energy drink cans that I found on the street. To get open cylinders, I remove the top and the bottom of the cans.
Cylinder dipole  -  PA1B
Energy drink cans
The cylinder dipole, that is tuned to 15 m, but also works very good on 10 m, consists of two aluminium energy drink cans of 500 ml. The top and the bottom of the cans were removed. The cylinders form the radiators of this antenna. The current on the surface of the cylinders, causes the radiation.
The coil has 9 turns and is wound on a PVC tube with a diameter of 80 mm. The taps are one turn apart
I have a lot of fun with this cylinder dipole in the shack at the first floor, 4 meter above the ground. This cylinder dipole can also be used on 20 m, with lower efficiency.

Parallel resonance
The cylinders show a large self capacity. This capacity is much larger than the capacity of a wire of the same length as the cans. The capacity of the cylinders and the induction of the coil form a parallel LC resonant circuit. The impedance of this LC circuit is high at resonance. 
Please notice, that this parallel resonance, is what makes the difference between the cylinder dipole and a dipole with very short wires.

Tuning
The cylinder dipole is tuned by choosing the number of turns of the coil.

Feed point
I made taps, at the center of the coil. The connection on the taps of the coil, form a feed point with low impedance, to which the 300 ohm twin lead is connected. The lower the number of turns between the taps, the lower the impedance will be. I had good results with the taps just ONE turn apart. 
Please notice, that because the taps are placed at center the coil, the ribbon will not radiate it self.

Matching
The cylinder dipole is matched (not tuned) by the symmetrical tuner in the shack. The tuner is adjusted to the lowest SWR

Multi band antenna
The cylinder dipole can be used as a multi band antenna, simply by matching the antenna to a SWR of 1:1 on the band that you want to use. That's all. 

Build - Work - Analyse 
I am curious about your results.

zondag 6 maart 2016

Confirmed DXCC countries with QRP

This table shows all the confirmed CW QSO's from September 2003 - August 2014, that I made under the call PA1B.

As a milliwatt enthusiast, I lower my power when the S-meter goes up. I often use the lowest possible power in each QSO. I use QRPp, when ever I can, but also use QRP when it is necessary to make the QSO. In most QSO's, I use S&P. This is search and pounce. I search on the band and answer a CQ of a loud station. I start with a low power and only increase my power when I am sure that my signal is not heard. I use attenuators to lower the power for QRPpp and QRPp. In every QSO that I make, I note my power in my log.

The table shows 12 power categories from 1 mW up to 5 Watts. But please notice that a QSO in the power category of 50 mW, can be made with a lower power than 50 mW. A power of 30 mW, 36 mW, 41 mW, 45 mW and 50 mW, are all  displayed in the power category of 50 mW.

Conformed DXCC-countries with QRP  -  PA1B

The total number 8 x 10 + 7 = 87 DXCC's.
I have made this table with great care. Please let my know, if something is not, what it should be.

zondag 28 februari 2016

Quite a distance

The 15" cylinder dipole amazes me time and time again.

Today I was surprised by the cylinder dipole that is made of two  Monster  energy  cans  and a coil that hangs inside the shack, on the first floor. This antenna with a length of 15 inches, has proven before, that it is doing fine on 21 MHz. After a number of QSOs's with Russia and the Ukrain, I made a QSO deep in to Russia.

An hour before the end of the UBA DX contest, I met Alexander R0AA from Atsjinsk. (Ачинск) My paper notes states that the QSO was easy. (makkelijk). This was QSO number 16 in the contest.

Later I realized that R0 must be deep in to Russia. On the map I saw that Atsjinsk lays east of Kazakhstan and north of Mongolia. hi. The distance is 5223 km or 3245 Miles. WOW.

R0AA - PA1B - 5223 km  - Cylinder dipole 15" - 4 watts 

One coil and Two Monster cans
Really amazing. HI.

donderdag 25 februari 2016

140 QSO's with the cylinder dipole

Since the ARI contest in May 2015, I made 140 QSO's with 3 types of cylinder dipoles. The table shows the 3 different cylinder dipoles that I used, in several contest in 2015 and 2016.

Build  - Work - Analyse

I made this table to show the number of QSO's, that were made, with each of the three types of cylinder dipoles that I have build.

Number of QSO's with different Cylinder Dipoles - PA1B
I used the Red Bull antenna in the ARI contest on 20 m and 40 m. At that moment 15 m and 10 m showed no activity. But the propagation on 20 m and 40 m  was excellent.
The 6 QSO's on 10 m were made in two different 10 m contests.

The Monster antenna, made of two Monster cans of 500 ml is an excellent, easy to build indoor antenna for 15 m, but also works on 20 m. The table show that it works better on 15 m that on 20 m.

The Booster with it's wingspan of 55 cm (22") is build for 20 m and 30 m and is until now, only used in the PACC.
In the PACC I made 27 QSO's on 40 m. The Booster works on 40 m and 20 m. In the PACC there was more activity on 40 m than on 20 m. But I suspect that the booster works best on 20 m,

The used the cylinder dipoles indoor from the shack or from a dormer window at the second floor, with a power of 4 W or less.

woensdag 24 februari 2016

Cylinder dipole in PACC

Booster - Cylinder dipole 22"
In the PACC I used a new cylinder dipole, that I have build recently.
I built the Booster to experiment with larger cylinders and a larger coil. To go below 15 m.

The  Booster  has two cylinders, that each are made
of 4  Energy Booster  cans of aluminium, that are cut open and bolted together. The length of each cylinder is 22 cm. The wing span of the dipole is 22 inches. The coil former has a diameter of 110 mm and the coil has 15 turns. The taps are two turns apart. The Booster resonates at 10 MHz.

The cylinder of 4 cans PA1B
On Friday I made the coil and just before the contest I made the taps on the coil. During the contest I used the taps that are two turns apart. The Booster could not be MATCHED with the taps 4 turns apart. I suspect that the impedance on the end of the twin lead in the shack is too low, or too high, for my symmetrical tuner. So I switched to the taps that are 2 turns apart. I later realized that I did not try taps that are one turn apart.

I started with checking the MATCHING of the Booster on 15 m, 20 m and 40 m. Matching on 15 m and 40 m is very easy. Matching on 20 m is difficult.

Before the PACC, I made the first QSO with the   Booster   on 40 m, with 7S6WRD from Sweden. My RST was 339. hi. Not a very strong signal, but it works.

PA1B in the PACC 2016 
PACC    
I made a total of 32 QSO's with the Booster. 25 QSO's were made on 40 m with 3 W and 2 QSO's with 150 mW. On 20 m I made 5 QSO's with 4 W.
I had no intention to make hundreds of QSO's, but I wanted to know, how the Booster would work. 

Saturday
On 15 m and 20 m there was no activity, So I started on 7 MHz. The first 3 QSO's were made with 2 Dutch stations (PA) and with F5IN, all with S&P. Then I stopped to visit some friend.
Around 17:00 utc, I started again on 40 m. I decided to give CQ. To my surprise, I was visited by stations from DL, HA, OE, OK (4), SM and UA (3). I was pleasantly surprise by the stations from Russia that answered my CQ, over a distance of more than 1300 miles.

Sunday
Sunday morning on 40 m gave a mix of stations from PA and DL. When the propagation peaked, I could QSO with PI4CC and with DL5JQ using just 150 mW. WOW. But in the next QSO's I needed a power of 3 watt. hi.
At about 11 utc I went to 20 m and made 5 QSO's with 5 DXCC countries, all QSO's with 4 W.

During the contest I frequently went to 20 m and 15 m. Most activity was on 40 m, as you can see in the table.

The Booster is doing fine on 40 m and 20 m. I worked 10 DXCC countries from the dormer window with the Booster at a height of 7 meters above the ground.

Cylinder Dipole by PA1B  -  Taps two turns apart
Click to enlarge
Cutting the cans  -  Mooi schaartje hè.



Click on the pictures to enlarge.




zondag 21 februari 2016

QRPp QSO with the Booster

In the PACC I tested a new cylinder dipole - The Booster. I tested on 7 MHz and 14 MHz with 3 or 4 watts. I use my cylinder dipoles as indoor antennas. I placed the Booster in the dormer window.(dakkapel).

As a milliwatt enthusiast, I enjoyed to make 2 QSO's with QRPp, which is less than 1 W.
When the propagation peaked on Sunday morning, I heard PI4CC, with a very loud signal. S9++.  I reduced to 150 mW, before answering their CQ and made the QSO. In the next QSO with Erhard DL5JQ, I also used 150 mW. His signal was also very strong, S9++. In the next QSO I first tried 150 mW, but I needed the full power of 3 watts to be heard. hi.

Yesterday I answered the eQSL of this very special QSO, with Erhard DL5JQ. After answering the eQSL,  I have sent Erhard an email via eQSL to inform him of my power and my antenna.

Hallo Erhard,
Fabelhaft!! Dein Signal war sehr stark. S9++. Ich habe in unserem QSO, einer Leistung von 150 mW verwendet. QRPp. Ich bin ein begeisterter Milliwatter. Wenn die S-Meter nach oben geht, geht meine Leistung nach unten.

In diese PACC habe Ich einen Zylinder Dipol versucht. Meine Antenne ist eine zylindrische Dipol in der Dachgaube. Die Flügelspannweite beträgt 55 cm. Informationen über die Antenne:
http://pa1b-qrp.blogspot.nl/2016/02/the-booster.html
Aber schauen Sie sich auch, das Etikett Cylinder dipole an.

Dank für das nette QSO. Ich hoffe du nächstes Mal zu treffen, mit niedriger Leistung. hi.
Mit freundlichen Grüßen,
Bert PA1B

DL5JQ  - 40 meter  - 150 mW  -  Booster

OK dear Erhard, thanks for the nice QSO and eQSL.

zaterdag 20 februari 2016

The Booster

First light for the Booster (hi)
The Booster is a cylinder dipole. The two cylinders, are each made from 4 Energy Booster cans from aluminium, that are cut open and bolted together.

Cutting the Energy Booster cans. Click to enlarge








I built the Booster to experiment with larger cylinders and a larger coil to work on 14 MHz and 7 MHz.

The Booster has twice the size of the Red Bull antenna.

The length of each cylinders is 22 cm. The wing span of the dipole is 22 inches. The coil former has a diameter of 110 mm and the coil has 15 turns. The taps are two turns apart.

The Booster resonates just above 10 MHz.

Giving CQ on 40 m with just less than 3 W on the Booster, resulted in contest QSO's with  DL (1), HA (1), OE (1), OK (4), SM (1) and UA (3)

The Booster in the dormer window (dakkapel) PA1B

Taps two turns apart. PA1B

zaterdag 6 februari 2016

UN3M on the Red Bull antenna

When I putted the Red Bull antenna into use in the ARI contest, I made 9 QSO's on 14 MHz and even 1 QSO on 7 MHz. At that moment I did not know that the conditions were extremely good. The Red Bull antenna with the coil of 14 turns on a tube of 40 mm, resonates on 26 MHz.
So now I was curious, how the Red Bull antenna would do on 28 MHz. 

I decided to participate in the DARC 10 meter contest, to make QSO's with the Red Bull antenna. A contest for 10 meter is a good opportunity to make contacts on that band, because it creates activity. The DARC 10 meter contest is a very short contest, that runs from 9:00 till 10:59 utc. I have been on the band for 90 minutes. During the whole contest, I did not hear any German stations, because of the very short distance to Germany.

After a few minutes I could make a QSO with LY2NK with 3 watts. Then the band was empty, but I had to stay on.
Much later I could make a QSO with UN3M. Nickolay is in the western part of Kazakstan. The distance is about 1950 miles. FB.

QSO with the  Red Bull antenna  on 10 mtr with 3 watts

maandag 25 januari 2016

Het lijkt wel lente

Vorige week moest ik nog handschoenen aan en een gebreide muts op, bij het fietsen. Maar vandaag werd het 14 graden. Toen ik om half negen weg ging naar fitness, was het al 8 graden op de termometer in de tuin. Op de terugweg was het zelfs zonnig.

Het was de warmste 25 januari, sinds de temperatuur gemeten wordt in De Bilt. Daar werd een temperatuur van 14,6 graden gemeten.

Vanmiddag hebben mijn vrouw en ik lekker gewandeld op het landgoed Oostbroek. We hebben het vernieuwde knuppelpad gelopen.

Het vernieuwde knuppelpad. Landgoed Oostbroek.
Dit knuppelpad is niet meer van hout, maar van metaal, omdat dit langer mee gaat dan hout. De metalen platen waar je op loopt, worden ondersteunt door een roest vrije metalen elementen. Het pad "zweeft" een halve meter boven de grond.



Gisteren wees mijn vrouw op dit bloemetje in onze tuin. Is de natuur in de war?  Ik denk het niet.