donderdag 24 april 2014

South America in the CQMM DX with my crippeled Inverted Vee

I was looking forward to the CQMM DX contest.
It is a very fine contest with a lot of activity from South America.
I know from earlier contests, that I could still make QSO's with low power, with my crippled antenna.
But I was wondering if I could make a QSO's with South America.

On Saturday I made 9 QSO's with Europe with a power of 5 watts down to 100 mW.

On Sunday afternoon I switched to 28 MHz and heard a station from South America.
At that time, I did not know whether the distance would be more than 5000 miles,
so I decided to use 2.5 W.
I use 2.5 watts and I used a lot of patience to make a QSO with PW2D.
The frequency had to be absolutely clear, so I had to stay cool. hi

With a distance of far more than 2500 miles, this QSO is a more than 1000 Miles per Watt QSO.
Later I heard other stations from South America, but they could not hear me, even with 5 watts. hi
The changes in propagation, are more important than the antenna.
So I say thanks to the fine operators of PW2D.

woensdag 23 april 2014

Lekke antilekband

Het kan dus wel
Het was toch mis
Er klonk een zacht gesis

(Een vingerhoed vol emotie. Maar t'is geen "HighKoe" of 俳句 )

Eerste paasdag
Nieuwsgierig veulentje.
Na het paasontbijt met paasstol met spijs en warme heel veel granen bolletjes, zijn we met de eFiets, even naar plas Middelwaard gefiets.
De hooglanders en de paarden stonden op het toegankelijke deel,
zodat we makkelijk foto's kon maken.
Mijn vrouw schoot dit mooie plaatje van het nieuwsgierige veulen.

Pfffff
Slechts honderd meter op de terugweg, hoorde ik een tikkend geluid, bij het voorwiel. Toen ik stopte zag ik een takje met doorntjes op de band zitten.

Hooglander met de hoeven in het water.
De doorntjes op het loopvlak waren plat en hadden geen schade aangericht.
Maar . . . één van de doorntjes prikte naast het loopvlak,
langs de zijkant, in de zijkant, van de band.
Dit doorntje zat behoorlijk vast en liet zich moezaam verwijderen.
Het was toch mis, er klonk een zacht gesis.
Toen we thuis aankwamen, was de band wel zacht,
maar nog niet leeg.

Daarna ben ik verder gegaan in de CQMM DX contest, tot 1 uur 's nachts. hi

donderdag 17 april 2014

CQMM DX coming up this weekend

Starts: 1200 UTC Saturday
Ends: 2359 UTC Sunday
This weekend there will be much activity
from South America, so join the fun
in the CQMM DX in which you can work every station.

In 2011,  2012  and 2013,
I had great fun with QRP in the CQMM DX contest.
Look at the:  
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.

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

CQMM DX coming up, this weekend.

Rules 2014
Click for    Rules 2014   or the CQMM DX website

dinsdag 15 april 2014

Ribbon of the Inverted Vee damaged

Last year the top of my Inverted Vee broke.
I fixed the antenna temporarily, so the height of the antenna was reduced with 2 meters.
When I wanted to replace the broken stick by a new one, I noticed that the
300 ohm ribbon was damaged.
Obviously the ribbon had made contact with the rough tiles.
Wear by continually moving over the rough tiles by the wind took its toll.
One wire of the ribbon was completely gone over a length of 5 cm. (2 inches)
So only one wire  of the inverted vee is connected.
Actually my antenna is just one wire of 10 m.

vrijdag 11 april 2014

"WSPR Propagation Analysis" for WSPR spots of G3XBM on 10 m

Roger, G3XBM wrote:
Nothing at all was seen until mid-afternoon and then the band just opened wide!  
K9AN (6505km) last spotted my 2W signal at 2308z, which is after midnight local time and HOURS after the band has normally died out. It had been dark for hours. One wonders if this was F2 or even multi-hop Es? I wonder what was happening on 6m transatlantic?  I must check.
(Spots made on 2014-04-08) Click to visit the article.

I was interested, so I made an WSPR Propagation Analysis of the spots on that day and the days before. The second table shows the last spot at 23:08 UTC, but also reveals the rapid change in propagation around 22:20 UTC.

How to read the table 
In the analysis above, I show the "Calculated Lowest possible Power" in milliwatt and the hours of the day in UTC. The lower the "Calculated Lowest Possible Power", the better the propagation.
To compare the propagation over several days, 
I included 2014-03-28 till 2014-04-08.


Roger is refering to WSPR spots made on 2014-04-08.
At the bottom of the table above.
From 10 UTC to 22 UTC the propagation gets better.
The best propagation occurred in the spot with the red star made on 22:20 UTC.



Even more spectacular
The best propagation on 2014-03-28, at the top of the table, occurred between 13:00 and 15:59 UTC in the aftenoon.
But even more spectacular is the change in propagation in the 3 spots * that were made between 22:00 and 22:22 UTC, that show a very rapid chang in propagation. (See the red arrows)

Thanks to Roger for the interesting experiments with WSPR.

vrijdag 4 april 2014

/QRP

I always use QRP, which is 5 watts or less in CW.  But I never use the tag /QRP.
In contest QSO's in CW, I rather send my call a second time in stead of /QRP.
In the BSCI contest I made a QSO with a station that was not in the contest.
I met a station from Guensey (GU) which is rather rare.

The signal was very strong, so I immediately reduced my power to 50 mW.
The FT-817 was set to 500 mW and I switched in the 10 dB attenuator.
The 10 dB attenuator reduces the power with a factor 10.
So my power was 500 mW diveded by 10 = 50 mW.
I received the usual 599 and I was happy to log MU0GRU.

But when I looked at the S-meter, I was surprised by the signal strenght.
Then I realized that I could have made the QSO with 5 mW.
In a contest it's (almost) impossible to make a second QSO (dupe).
But I decided to give it a try.
I switched in the 20 dB attenuator and gave my call PA1B/QRP, now using the tag /QRP,
now with just 5 mW.
To increase my luck, I decided to use the tag /QRP for a second QSO.
I thought that if I did not use the /QRP, I could not make the dupe, but MU0GRU came back for me
and I could make the second QSO, now with 5 mW. hi
Thanks to the friendly operator of MU0GRU.

I hope to receive a QSL. Until now I received a card for a QSO with 500 mW from Guensey.

zondag 30 maart 2014

CQ WPX SSB

On Saturday I made 7 QSO's in the CQ WPX SSB.
I wondered if I could make QSO's in phone with my crippled inverted V.
Last year the top broke.
I temporarily repaired the antenna, but one wire lays flat on the roof.
In the last months, I noticed that I need more power than before in CW contest QSO's.
Also I had to rediscover the "tuner settings" for each band, after the antenna had changed.

SSB also works
Using SSB in stead of CW gives a lot more QRM in the house.
Sometime I want to hold the microphone to my ear, to listen. hi
Saturday afternoon I had one hour to operate, in which I made 5 QSO's on 21 MHz with
LZ, IS0, I and EU.    I responded to signals that were S+.

Tuning
In the evening I went on, but could not be heard. The in coming signals were S+, thus strong enough, but my QRP signal could not be heard. After not being heard by 3 different very loud stations I checked my power.
After tuning with CW, as I always do, I had forgotten to switch back to SSB, so I had no power at all.
After that I made two additional QSO's. Then I had to QRT, since the XYL went to bed.

Your signal is weak
On Sunday morning I easily made 5 QSO's on 7 MHz over short distances with DL, ON , PA and G.
Many operators told me that my signal was weak. But I have no tower, no Yagi, a less than perfect Inverted Vee and QRP and still managed to make QSO's, somtimes pushing the operating pratice to the limit at both ends.
Using QRP and a simple antenna, shows that Progation is more important than the Antenna. hi.

zaterdag 29 maart 2014

Pacemaker

De pacemaker heeft vanaf 1958 een enorme ontwikkeling doorgemaakt, zowel in de electronica als de behuizing. De eerste pacemakers waren uitwendig en waren uitgevoerd met buizen, in kasten op wieltjes.
Later kwamen de uitvoeringen met transisitoren, die toen nog op het lichaam gedragen werden.

Nostalgie
Net als mijn eerste zelfgebouwde radio, de Philips Pionier, waren de eerste getransistoriseerde pacemakers met PNP transistors uitgevoerd.
Schema van een pacemaker met PNP transistoren
Uitwendige pacemaker in Kiwi schoensmeer doosje 1958
Nu
De huidige pacemakers bevatten een complete computer, uiteraard zonder toetsenbord en monitor en worden in het lichaam gedragen. De computer maakt de pacemaker programmeerbaar en stelt deze in staat om onregelmatigheden in de hartslag op te merken en op te slaan in het geheugen. Zodat deze info later tijdens het bezoek een aan het ziekenhuis uigelezen kan worden. De pacemaker bevat ook een batterij, omdat deze langer meegaat dan een accu.


Voor het verbinden van de pacemaker met het hart worden twee elektrodengebruikt.
De elektrode

Uitvoeringsvormen van de punt van de elektrode 

De foto's zijn gemaakt tijdens de zeer informatieve bijeenkomst voor pacemakerdragers in het st Antonius ziekenhuis in Nieuwegein.  Ik heb mij hier beperkt tot het voor het "radio" Blog interessante gedeelte.

vrijdag 14 maart 2014

Homebrew 10 watt dummy load

For years I use a very simple homebrew 50 ohm - 10 watt dummy load.
At a moment, I realized that 20 resistor of 1000 ohm in parallel form a resistor of 50 ohms.

So I bought twenty 1000 ohm - 1/2 watt resistors and soldered them on a PL 259 connector.
Through the green tube runs a wire to connect the wires of the resistors to the left, with the
center conductor of the connector.
The twenty resisitors can dissipate a power of 10 watts.

The dummy was measured in a workshop of Rohde & Schwarz.
At the moment I can not find the report of the measurement.
I first wrote that the dummy load was 49.9 ohms, but I now remember
that it was 49.8 ohms.
I was surprised the resistors had an accuracy of better then 1%. hi

10 watts - 50 ohm HF dummy load
  

vrijdag 7 maart 2014

Spring

Looks like it will be spring.
We have very nice temperatures.
Yesterday my wife and I went for a walk in Rhijnauwen, along the Kromme Rijn.

Langs de Kromme Rijn
Sneeuwklokjes

vrijdag 28 februari 2014

Guust is 57

Guust
Guust is 57.
Wat een verassing.
Zo'n 40 Jaar geleden was Guust mijn favoriete stripfiguur.
De boeken zitten in een doos op zolder,
maar mogen (nog) niet weg.

Toen ik de Google doedel zag, moest ik ook aan de meeuw, juffrouw Jannie en de flaterfoon denken. Hi.

Flaterfoon

zaterdag 22 februari 2014

HA-DX contest 2014

I had great fun with low power in the HA-DX contest.

I had to rediscover, what my Inverted vee would do.
In earlier contest I experienced, that I would need the full power
on 7 MHz and 3.5 MHz.

From the Cabrillo log:
SOAPBOX:       I fixed my Inverted Vee temporarily after a storm last year
SOAPBOX:       One wire is flat on the roof, but I still make QSO's
SOAPBOX:       Had great fun with QRPp and QRP from 100 mW to 5 watts
SOAPBOX:       Thanks for the activity in the contest

On 14 MHz my antenna is still working well.


I many QSO's on 40 m and 15 m, I had to use the full power of the FT-817.
But when the S-meters goes up, I can reduce the power.
I could also make QSO's with QRPp.
I had a remarkable QSO with HG8C.
When I gave my call with 500 mW, there were other stations also calling, but he came back for me.
This doesn't happen often. hi. Most of the time I must wait, till the frequency is clear.
I even had a QSO with 50 mW with RM22HD outside the contest.

dinsdag 18 februari 2014

REF CW 2014

In the end of January I participated in the REF CW contest.
In recent years I made many QSO's in this contest with 50 mW.

The top of my inverted vee was broken last year in a storm and I made a temporaly repair. One of the wire lays on the roof.
So I had to experience how the antenna would work.

On Saturday I made 2 QSO's on 20 m with 50 mW and 100 mW.
On Sunday I made 14 QSO's on 40 m.
In these QSO's I had to use the full 5 watts of the FT-817 due to the antenna.

Further I made a number of QSO's on 20 m with a power of 50 mW to 500 mW.
The inverted vee with one wire on the roof works for 20 m.
But on 40 m it takes more power to make QSO's.

When the propagation is good, it's not that difficult the make QSO's with very low power.
On Sunday the signal of F6KNB was S9 + 10 dB. So I decided to try a power of 50 mW.
I gave my call just once and got an immediate respons. FB.


zondag 16 februari 2014

ARRL International DX CW

I started late, because the grand children stay with us this weekend.
This afternoon we went to the park in stead of participating in the ARRL int. DX contest.

My inverted Vee is still temporaly fixed after a storm last year.
One wire lays on the roof.
But I can still make QSO's even with low power in many different contests.

I need more power than the usual 1 or 2 watts, that I use most the time.
So I use the maximum power, that is about 4 or 5 watts.
Even the stations that I receive with S8 are more difficult to QSO than last year.

After a few hours in the contests there are 15 QSO's in the log.
But it's still fun to participate in this fine contest.
There was only one station, that was puzzled by my exchange 599 003, when I use about 2.5 Watts. hi
Let see what tomorrow brings.

zaterdag 8 februari 2014

DL1SDZ's WSPR spots with 0,5 milliwatt

On his blog Hajo DL1SDZ reports spots made with 200 mW down to 0,5 mW on 30 meters.
He reduced the power from day to day.

Hajo wrote me that the 4 last spots with 1 milliwatt were actually made with 0.5 milliwatt.
In the WSPR data Hajo uploaded the spots of 0,5 mW as 1 milliwatt, since this is the lowest value that can be used. (1 mW is 0 dBm)
Because my excell sheet can not calculate with a power lower than 1 milliwatt, I left the values for 1 milliwatt in the analysis of yesterday .

But today I calculated the lowest possible power for the value of 0.5 mW by hand
and made the next table exclusively for the spots with 0.5 mW.
The calculated lowest possible power is, in some spots, only one step lower.



This table show 4 spots in stead of 3.

The table below that I made yesterday, does include spots of 400 km or more,
so it does not include the spot by HB9JAQ

Click to enlarge
This analysis shows the calculated lowest possible power.
The lowest possible power is calculated from the power sent and the SNR.
The lower the lowest possible power, the better the propagation.