PA1B 0 - 36 dB Attenuator for QSO's

Last week, the info  on the interesting Attenuator page  of my web site was updated.
I added new info on the PA1B 0 - 36 dB Attenuator, specially designed for QSO's (Click)
I also placed new info on the PA1B 0 - 36 dB Attenuator, under the Tab's on the top of this Blog.

A simple way to reduce the power of your QRP transceiver, without modifying the set, is the use of attenuators.  This accurate PA1B  0 - 36 dB attenuator, is an excellent attenuator, to use in QSO's with very low power. This attenuator enables you, in contest QSO's, to go to the next setting instandly, when your call is not heard.
The combination   20 dB - 10 dB - 3 dB - 3 dB  is very quick to adjust in contest QSO's.
The choice of the values, makes it very easy to calculate the power at the output instantly.
This accurate Power Attenuator is designed for the use in QSO's.
With only 4 switches it is surprisingly fast and easy to operate.

Power Attenuator Calculator
I use the excellent Power Attenuator Calculator (Click), for the
design of the Power Attenuators.
With the Power Attenuator Calculator, you can design an attenuator for any input power.

Read more about attenuators on the attenuator Page.

On  my web site: Home - PA1B QRPp page 

PACC with QRPp

Although I had to take it easy, I had fun with QRP and QRPp in the PACC.
I found out that calling CQ was to much for my.
After just 3 QSO's, with 360 mW, in just less than 3 minutes, I had to take some rest.

So I decided to work in a relaxed way, with Search and Pounce.
I worked with Search and Pounce from 2.7 watts down to 1.8 milliwatts
When the S-meter goes up, my power goes down.

I frequently alternated S&P and calling CQ, with just 800 milliwatts.
While calling CQ with 800 mW, I made a total of  30 QSO's , in a number of short run's.
In the last 15 minutes of the contest I made a run of 13 QSO's with 2.7 W.
To my surprise, I noticed only a small difference between 800 mW and 2.7 W.

I worked YT6T with 8 mW and LZ6C with only 1.8 mW.
It's a long time since I could make QSO's with less than 5 milliwatts. hi
The signal of LZ6C wasvery strong:  S9 plus more than 20 dB.

REF CW contest 2013

This year I only participated for a total of 45 minutes on Sunday.

In a relaxed way, I used search and pounce with the use of the lowest possible power in each QSO.

The conditions were good for the use of low power on 14 MHz.
On 14 MHz all QSO are good for 1000 Miles per Watt.

Despite the short distance to France, 5 out of 6 QSO's are made with QRPpp*.

On 7 MHz I had to use the maximum power of 2.7 watts in most QSO's.

The changes in propagation can be very large.

In the afternoon, I met a station from Corsica, that I had worked earlier with 360 mW.

I tried to make an second QSO with 36 mW. His signal was S9 + 10 dB. He recognized my call and gave QSO B4. I gave a new report. But then we ended up, transmitting at the same time. So.....this QSO will probably not make it into the log. hi

I enjoyed the opportunity to work with very low power in the REF CW contest.

QRPpp* is the (not official) term that I use for a power of less than 100 mW. Bert PA1B QRPpp

QRPp in the ARRL int DX contest

In my first ARRL international DX contest, I used 5 watts. My exchange 599 005 gave no problem for the receiving station.  In CW of course given as:  5NN TT5.
It was obvious, that I was using QRP.

I very much like the ARRL international DX contest. In this contest, the DX stations, like myself, will give their power in the exchange. So the receiving station knows immediately, that I am working with QRP.

 When the S-meter goes up my power goes down. 

In most contest QSO's, I often use the Lowest Possible Power, in each QSO, using S&P.
When I hear a station calling CQ, I look on the S-meter to determine the power with which I will answer.

In later years, I reduced to 500 mW, when the propagation was very good. The use of 500 mW in a contest QSO is no problem, because most of the time, the response will be immediate and correct.

pwr? . . .100? . . . 1kW?  .  .  .  .  .  .  . 1W FB

The lowest value for the power in the Cabrillo file is 001.
Over the years, I found out, that when I was using 1 W, it was best. to use the exchange 599 001.

How to indicate, that I am using only 500 mW? Well, that's simple. The DX station give their estimated power. So for a power of less than 1 W, I also give the exchange : 599 001.

But don't think that all problems are gone with 599 001. Some stations keep asking pwr?, because they think that 001 is a number or they respond with 100? or even 1kW?.
In that case I will respond with:   599 1W 1W 

* I met operators, that fall out of their chair, when they realized, that my exchange 599 001 indicated, that I was using only 1 watt.
Two seconds of silence and an additional "1W FB", from a station that is transmitting not a letter to many, I consider a huge compliment. hi

Please notice that when you use low power, that any QSO between Canada or the USA with Europe with 3 Watts or less, is good for 1000 Miles per Watt.

Power of the FT-817 at PA1B's, after serious mis-match.

Power with WSPR

WSPR vs CW 13 dB

How much power should be used with WSPR?
WSPR is a beacon system. The WSPR data can be used to probe radio frequency propagation conditions.  
WSPR uses a low transmission speed.
The lower the transmission speed, the lower the power, that is needed. 

As you will see:  Please WSPR  with QRP.

Roger G3XBM asked Joe Tailor K1JT about the difference between "CW by ear" and WSPR.
Roger placed Joe's response in an entry
on his Blog:
WSPR versus CW - what's the improvement
Click to go to the article.

In a description on the WSJT web site, Joe gives a comparison between WSPR and CW by ear. 

For "CW by ear" Joe gives a SNR of -18 dB for a very skilled human CW opererator.

Joe gives a value of -29 dB for the SNR for a WSPR signal.

So the difference is 11 dB, but Joe estimates that for most operators, the SNR has to be even 15 dB. 

I estimate that the difference between WSPR and "CW by ear"  is about 13 dB for contest CW operators and 15 dB for most operators.

For an advantage of 13 dB, a power of 5 Watts in WSPR, can be compared with 100 W in CW.

So the power in WSPR can be 1/20th of the power in CW.

The value of 13 dB is guideline to estimate the power that you should use in WSPR to approach the situation that you use with CW. 

For an advantage of 15 dB a power of 5 Watts in WSPR, can be compared with 150 W in CW.

So the power in WSPR can be 1/30th of the power in CW.

Calculating with power, 15 dB corresponds to a factor 30,
13 dB is 20x, and 11 dB is 12.5x
Calculating with voltage, 15 dB corresponds to a factor 5.5,
13 dB is 4.5x and 11 dB is only 3.3x

I made a table below to compare WSPR with "CW by ear".

The table shows the values for 15 dB, 13 dB and 11 dB. So you can choose the value yourself.

Please note that a difference of 2 dB or 4 dB is very small compared to the large daily fluctuations (in dB) caused by the propagation.

I very much like the table of 13 dB. (20x)   I estimate that the value of 13 dB, is the value for the skilled CW contest operators. The values are easy to remember, since 100 W in CW can be compared with 5 W in WSPR. So when you use WSPR, please reduce your power to 1/20th of the power that you sue in CW.

If you want to analyse what is possible with QRP in CW, you can use 200 mW (23 dB) with WSPR.
This can be compared with 4 W in CW.

As a low power enthusiast I often use the lowest possible power in CW contest QSO's.
I often use less than 1 W. To analyse the possibilities with 1 W in CW, you should use a
power of 50 mW (17 dB) or less. hi

Please note that WSPR with 100 W can be compared with 3000 W, 2000 W or 1250 W in CW.

So gentleman, please:
                 Think in  dB,  and  WSPR  with   QRP.  hi.

Raspberry Whispers

On the interesting Blog of M0XPD is a very interesting article about WSPR experiments with the RPi.
Read the article: Raspberry Whispers by M0XPD.

I just visited the WSPR data base to collect a list of WSPR spots. And made an Analysis of the WSPR spots that M0XPD made on 30 meter with a power of 200 mW.

The stations that are mentioned in the article Raspberry Whispers have Excellent Ears. (Sensitive receivers)  The lower the Calculated Field strenght  in the better the propagating or the more sensitive the receiving station.

WSPR Analysis
The distance is given in steps of 100 kilometers.
A distance of 250 to 349 km will show up as 300 km.
PI4THT at a distance of 635 km, is placed in the category 600 km.

To compare spots, that are made with a different power (dBm), I calculate the lowest possible power of each spot, using the SNR and the power (dBm) of the transmitting station.

To compare the spots of stations at a different distance, I calculate the Field strength of each spot. This calculation includes the distance in km. In the table, I chose for microVolt/meter, to get nice values.

For one receiving station, the changes in Field strength follow the changes in the propagation to that station.

• The lower the Field strength, the better the propagation.

While comparing two receiving stations:

• The lower the Field strength, the more sensitive the station. 

The RPi is working well.

Plas Middelwaard with snow

Yesterday morning my wife and I went for a walk around Plas Middelwaard.
At the last moment I grabbed the camera.
The low temperatures formed intriguing ice structures.

    

 

At first it was overcast, but later the sun came through.






I discovered how I can adjust the camera for a close up. As you can see in the jellyfish that was formed by nature.







Later we visited a fish shop. Here I took the last icy picture.

HA-DX contest 2013

I enjoyed working with my new Inverted Vee in the HA-DX contest. At the end of 2012 Walle PE2WJW repaired my antenna which was damaged in a storm late November. The HA-DX contest was the first DX contest,  in which I could test the new antenna.
The new antenna works well.

When I started on Saturday afternoon on 20 m, I heard HA8MD with S8 +20 dB, so I immediately made a QSO with just 8 mW. This first QSO was also the QSO with the lowest power in this contest.
After that I made 4 more QSO's with very low and very low power: HA8IB - 36 mW, RA3RFA - 800 mW, UA2FL - 36 mW and HA1ZH - 360 mW.
A very good start. After that I got on the bike, because it was sunny whether.

On Sunday mornong I made QSO's on 40 m, 20 m and 15 m.
After the contest I went for a walk in the park. Not because it was sunny. It was snowing and there was wind. The very small snow flakes were moving almost vertically, so I could'nt resist. hi

In all QSO's I used the Lowest Possible Power with search and pounce in CW. So the used power in each QSO, is a very good indication of the propagation at that moment.
When I use the lowest possible power, it not always easy. Sometimes I have to give my call many times before my weak signal is heard. The frequency must be absolutely clear.

26 Out of 34 QSO's are made with more than 1000 Miles per Watt, considering the distance to the worked stations.  hi

Award for the IARU HF 2011

I enjoyed participating in the IARU HF World Championship 2011.
After I came home from my holiday, I discovered that I had not sent in the Log. At first I was disappointed, but then I realized that the activity that the contest offers, provides the opportunity to make interesting QSO's.  I had great fun with QRP and QRPp in 125 QSO's, of which many are 1000 Miles per Watts QSO's. Despite the deadline I sent in.

At the time I sent in the Log, I wondered whether my log would be marked as check log or would be ignored.
The contest robot immediately replied with a e-mail, in which he stated that the Log was received ***AFTER DEADLINE***. And in the same mail the robot kindly thanked my for participating and for submitting the log. hi.

Click on the
label: IARU HF
at the right to see the
related Blog entries.






A while back, to my surprise, I received a beautiful
Award for the IARU HF World Championship 2011.
Country winner:  First place - Single operator - CW only - QRP
It's great fun to participate with QRP and QRPp, but it's even more fun to receive an Award.
I very much like this gesture of great sportmanship.
So my thank goes to the Contest Commity of the IARU HF World Championship. (VE6SH and his team)

Inverted Vee repaired

After the Inverted Vee was damaged in a storm, I found Walle PE2WJW willing to go onto the roof. For a week we were looking at the whether. Yesterday the "window for dry whether" was width enough to go onto the roof. Walle first recovered the feeding ribbon and top part of the old Inverted Vee from the roof. I attached new wires (indoors) and Walle installed the new antenna on the roof again. It was dark already, when the job was done.

That evening I listened for a short while. I did hear some activity, but the signals were weak.
The next day I made a QSO with 360 mW with Laszlo HA6NL in the OQRP contest.
Good for more than 1000 Miles per Watt.

I find it difficult to compare antenna's.
Before the the repair, I made a few QSO's in the Croatian CW (Click) on the remaining wire of the damaged antenna. At that time the signals were very strong.
I just looked in the Log and found out, that I also made a QSO with HA6NL with in the Croatian CW.
Laszlo's signal was very strong, 10 dB over S9, so I used 36 mW. hi

So I think that the new antenna is working well, but that the difference is caused by the propagation.

Croatian CW contest

I had great fun in participating in the Croatian CW contest, on a wire of 10 mtr.
I did not expect this amazing result with my crippled antenna. The inverted Vee lost one of it's wires in the storm in November. I used the remaining wire that lies partly flat on the roof.

I had to take it easy, so I did not make many QSO's. But I still had fun. On Saturday I started with 5 QSO's on 40 m, in which I had to use 2.7 watts.

After 2 more QSO on 40 m on Sunday morning , I went to 20 m. I was surprised by the signals on 20 m. The signals were very strong S9 plus 10 dB.
So I immediately decided to use the lowest possible power.

With the pre-programmed messages and the pre-programmed serial numbers in the Morse Machine, I effortlessly made the QSO's on 20 m. 

Please notice:  Propagation and Activity are much more important than the antenna.

Who would expect, that I could make 4 QSO's with just 36 mW on a wire of 10 mtrs. Well, I would'nt.
All the QSO's on 20 m are made with more than 1000 Miles per Watt. So I don't complain about my antenna, but I am grateful  for the excellent propagation.

Half an Inverted Vee

While I was in the hospital the storm damaged my antenna. 
Since I have to recover first, I can not repair the antenna. I found a HAM who is willing do the repair. In the mean time I will use the half Inverted Vee. hi

The top of the antenna came loose and dropped to a point 2 mtrs above the roof. Later the wire that is (was) visable on the photo broke. The wire on the opposite side of the house lies partly flat on the roof. Much to my surprise I managed to make a few contest QSO with very low power. 2.7 W down to 36 mW. 

UA1CEG/P in the Croation CW from the forest

Yesterday I received a fascinating photo story in PDF from UA1CEG/P.

Yuri has been active from the forest in the Croatian CW contest with a homebrew transceiver of 3 watts and a Delta antenna for 20 m.
The photo story in PDF shows the beautiful snow landscape in which Yuri was operating from his Wigwam shack.



The mercury dropped to a value of 15 degrees Celsius below zero. Brrrr. The photo's also show some of the pages from Yuri logbook.
I enjoyed reading and viewing the  photo-story.

Thanks to Yuri UA1CEG for writing the story and to Oleg RV3GM for the translation into English.

Большое спасибо за интересный рассказ. Мне понравилось.


Download the photo story here:
https://dl.dropbox.com/u/8362439/ContestInForestUA1CEG-P.pdf

Weer thuis Back home

Eind november ben ik met spoed opgenomen in het ziekenhuis. Ik was onwel geworden. Het bleek aan mijn hart te liggen. Nadat de hartslag enkele dagen bekeken is, is er een pacemaker geplaatst. Ik moet het de komende weken heel rustig aan doen.

Hospital

Bert is in the hospital.
He is already getting better,but will be in hospital for the next day's.

Hennie          XYL