Month: February 2014

I have never QSOed on the 6m band, but last Sunday when I happened to watch on the band in the afternoon local time, I heard some VK stations for the first time.

I was using a dipole antenna for the 15m band, so I decided to add an element for the 6m band. It took me about five minutes or so to get ready to call, and at that time the signals were with heavy QSB. I called a couple of stations for several times, but only in vain.

I hope to contact some DX stations on the band next weekend.

By listening to the morse code audio files with QSZ 3, I noticed I almost always miss the same particular words independent of the speed of the code. It does not matter whether it is at 25wpm, 30wpm, or 35wpm.

The longer the word, the more difficult it becomes to get the word. And if I miss at the first time, listening to it two more times does not help much in most cases.

Some examples are:

 10 absolutely
 10 acceptable
 10 additional
 ...
 11 advertising
 11 alternative
 11 application
 ...
 12 championship
 12 construction
 12 contribution
 ...
 13 automatically
 13 communication
 13 comprehensive
 ...
 14 administration
 14 recommendation
 14 transportation

Maybe I should concentrate on words, say length more than 10, to save my time

% gawk '{print length($1)}' English2000.txt > English2000-length.txt
% R
> data=read.table("English2000-length.txt")
> hist(data$V1,xlim=c(0,14),main="Histogram of Word Length",xlab="Word Length",col="green")

QSZ? means “Shall I send each word or group more than once?”

I hate to admit this, but I am far from perfect in copying morse code even at, say 35wpm. That is especially true with longer words, in which case I tend to miss the latter half of the word. So I thought it might help to repeat each word two or three times like this:

% gawk '{print $0,$0,$0}' message.txt > message-rep3.txt
% ebook2cw -w 35 -W 3 -f 600 -s 8000 -b 16 -q 1 -o message-rep3-35wpm message-rep3.txt

Let’s see if I can get any words at least after the final repeat.

I do not understand why it happens, but sometimes (only sometimes) my dots out of Vibroplex Blue Racer become very unstable. Apart from the initial chatter when the contact closes, there is somewhat delayed bounce of the contact (red), which is observable by listening to the side tone (yellow). See the third and the fourth dots. I have not checked the RF signal yet, but I presume there is also some annoying effect, too.

To avoid any loose contact at the pivot, I am using a jumper to directly connect the lever to the ground, but it does not improve the situation.

Another example. This time see the 1st through the 3rd dots.

Impedance measurement for my new dipole for the 15m band.

gnuplot> load "gnuplot.txt"
Freq [MHz]=21.03
V1=1.6
V2=2.0
Cursor 1=-4.5e-09
Cursor 2=0.0

vratio=1.25
phase1 [deg]=-34.0686
phase2 [deg]=0.0

abs(gamma)=0.70112862738752
swr=5.69184198713212
cz={17.8937141914241, -49.2890662925202}

My power meter says that Pfwd=10.0W and Pref=4.0W, which means SWR=4.4.

 Vref=sqrt(4.0/10.0)=0.6324
SWR=(1.0+0.6324)/(1.0-0.6234)=4.4

Considering the cable length of 20m, Zant=280.884+j31.809.

My first two Canadian stations during the ARRRL contest on the 15m band, both in Alberta.

I also worked with w1aw/5 ca in the morning on this band. My first w1aw was /5 tx on the 40m band, and this is my second.

As a wire antenna user, I usually do not consider the fact, but there is certainly a big difference in the paths. No wonder it is difficult to QSO with east coast stations for me.

Got Arizona, Idaho, Iowa, Massachusetts, Tennessee, and Vermont stations during the contest on the 15m band. Now I have worked with 18 out of 50.

Removed my old antenna, and set up a dipole for 21MHz only. Since DX stations are required to send signal report and power, I am running with 50 watts so that I can simply send 5nn5t.

Got a Tennessee station in the morning, which gives me the 13th state for my WAS hunt.