決して絶望するなかれ!

Farewell Statement from Senator John McCain

“My fellow Americans, whom I have gratefully served for sixty years, and especially my fellow Arizonans,

“Thank you for the privilege of serving you and for the rewarding life that service in uniform and in public office has allowed me to lead. I have tried to serve our country honorably. I have made mistakes, but I hope my love for America will be weighed favorably against them.

“I have often observed that I am the luckiest person on earth. I feel that way even now as I prepare for the end of my life. I have loved my life, all of it. I have had experiences, adventures and friendships enough for ten satisfying lives, and I am so thankful. Like most people, I have regrets. But I would not trade a day of my life, in good or bad times, for the best day of anyone else’s.

“I owe that satisfaction to the love of my family. No man ever had a more loving wife or children he was prouder of than I am of mine. And I owe it to America. To be connected to America’s causes – liberty, equal justice, respect for the dignity of all people – brings happiness more sublime than life’s fleeting pleasures. Our identities and sense of worth are not circumscribed but enlarged by serving good causes bigger than ourselves.

“‘Fellow Americans’ – that association has meant more to me than any other. I lived and died a proud American. We are citizens of the world’s greatest republic, a nation of ideals, not blood and soil. We are blessed and are a blessing to humanity when we uphold and advance those ideals at home and in the world. We have helped liberate more people from tyranny and poverty than ever before in history. We have acquired great wealth and power in the process.

“We weaken our greatness when we confuse our patriotism with tribal rivalries that have sown resentment and hatred and violence in all the corners of the globe. We weaken it when we hide behind walls, rather than tear them down, when we doubt the power of our ideals, rather than trust them to be the great force for change they have always been.

“We are three-hundred-and-twenty-five million opinionated, vociferous individuals. We argue and compete and sometimes even vilify each other in our raucous public debates. But we have always had so much more in common with each other than in disagreement. If only we remember that and give each other the benefit of the presumption that we all love our country we will get through these challenging times. We will come through them stronger than before. We always do.

“Ten years ago, I had the privilege to concede defeat in the election for president. I want to end my farewell to you with the heartfelt faith in Americans that I felt so powerfully that evening.

I feel it powerfully still.

Do not despair (emphasis added) of our present difficulties but believe always in the promise and greatness of America, because nothing is inevitable here. Americans never quit. We never surrender. We never hide from history. We make history.

“Farewell, fellow Americans. God bless you, and God bless America.”


To those who can hear me, I say – do not despair.

MathJax

MathJax allows you to include mathematics in your web pages, either using LaTeX, MathML, or AsciiMath notation, and the mathematics will be processed using JavaScript to produce HTML, SVG, or MathML equations for viewing in any modern browser.

<head>
...
<script src='https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.4/latest.js?config=TeX-MML-AM_CHTML' async></script>
...
</head>

\begin{equation}
\begin{pmatrix}
M&m_1&m_2&0 \\
0&m_{1}&-m_2&0 \\
2&-1&-1&0
\end{pmatrix}
\begin{pmatrix}
A \\ a\\ b\\ T
\end{pmatrix}
=
\begin{pmatrix}
F-Mg-(m_1+m_2)g \\ (m_2-m_{1})g \\ 0
\end{pmatrix}
\end{equation}

\begin{equation}
H_c=\frac{1}{2n} \sum^n_{l=0}(-1)^{l}(n-l)^{p-2}
\end{equation}

\begin{equation}
\left.\begin{aligned}
B’&=-\partial\times E, \\
E’&=\partial \times B – 4\pi j,
\end{aligned}
\right\}
\qquad \text{Maxwell’s equations}
\end{equation}

PDS5022SとOwondump(2)

オリジナルのプログラム、owondump.c 0.3を、ほんの少しだけ改変しています。

Display Set Menuで、Carryを手動で選択することにより、”owondata.bmp”もしくは”owondata.txt”を得ることができます。

% gcc -o owondump owondump.c -lusb
% sudo ./owondump
% gnuplot
gnuplot> plot 'owondata.txt' using 1 with line, 'owondata.txt' using 2 with line

PDS5022SとOwondump

% gcc -o owondump owondump.c -lusb
% sudo ./owondump
% gnuplot
gnuplot> plot 'output.bin.txt' using 1 with line, 'output.bin.txt' using 2 with line

SDR用のアンテナスイッチ(5)

Airspy HF+の仕様は;
+10 dBm Maximum RF input.
となっています。

IC-7410の最大出力は100Wなので、40dB以上の減衰量がアンテナスイッチには求められます。

非常に雑な実験をしてみると、送信RFパワーが7MHzで35dBmの場合、受信機ポートには-6dBm (=S9+67dB)程度の漏れがあるので、41dBの減衰があることになります。

Airspy HF+とIC-7410をRaspberry Pi 3で

WSJT-Xを2つ同時に起動します:

% wsjtx --rig-name=IC7410 &
% wsjtx --rig-name=AirspyHF &

pi@raspberrypi:~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
  Subdevices: 7/7
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 ALSA [bcm2835 IEC958/HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 1: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 2: CODEC [USB Audio CODEC], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
pi@raspberrypi:~ $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 1: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 2: CODEC [USB Audio CODEC], device 0: USB Audio [USB Audio]
  Subdevices: 0/1
  Subdevice #0: subdevice #0

WSJT-XとGridTracker

GridTrackerは、WSJT-Xに随伴するプログラムです。

あなたは、このプログラムがPSKreporterでは提供されない情報を与えてくれることに気がつくかも知れません。

このケースでは、2つのプログラム、WSJT-XとGridTrackerは、同じマシン上で動作しています。

そして、このケースでは異なるマシン上で。

Raspbian Stretchとsystemd-timesyncd

pi@raspberrypi:~ $ lsb_release -a
No LSB modules are available.
Distributor ID:	Raspbian
Description:	Raspbian GNU/Linux 9.4 (stretch)
Release:	9.4
Codename:	stretch

pi@raspberrypi:~ $ uname -a
Linux raspberrypi 4.14.34-v7+ #1110 SMP Mon Apr 16 15:18:51 BST 2018 armv7l GNU/Linux

pi@raspberrypi:~ $ ps aux | grep time
systemd+   276  0.0  0.4  17276  4012 ?        Ssl  Jun18   0:00 /lib/systemd/systemd-timesyncd

pi@raspberrypi:~ $ timedatectl status
      Local time: Tue 2018-06-19 01:55:55 UTC
  Universal time: Tue 2018-06-19 01:55:55 UTC
        RTC time: n/a
       Time zone: Etc/UTC (UTC, +0000)
 Network time on: yes
NTP synchronized: yes
 RTC in local TZ: no

pi@raspberrypi:~ $ cat /etc/systemd/timesyncd.conf
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See timesyncd.conf(5) for details.

[Time]
#NTP=
#FallbackNTP=0.debian.pool.ntp.org 1.debian.pool.ntp.org 2.debian.pool.ntp.org 3.debian.pool.ntp.org

pi@raspberrypi:~ $ ls -l /var/lib/systemd/clock
-rw-r--r-- 1 systemd-timesync systemd-timesync 0 Jun 19 01:59 /var/lib/systemd/clock

Airspy HF+とRaspberry Pi 3でFT8

FT8信号をデコードする非常に小さなシステムです。

pi@raspberrypi:~ $ uname -a
Linux raspberrypi 4.14.34-v7+ #1110 SMP Mon Apr 16 15:18:51 BST 2018 armv7l GNU/Linux

pi@raspberrypi:~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
  Subdevices: 7/7
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 ALSA [bcm2835 IEC958/HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 1: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
  Subdevices: 7/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7

pi@raspberrypi:~ $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
  Subdevices: 7/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 1: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7

pi@raspberrypi:~ $ lsmod
Module                  Size  Used by
snd_aloop              24576  4