Month: August 2014

So this is my operation desk. I think I can use a little bit larger desk, but be satisfied with what you have. A small desk for a small station, you know.

This is a dipole for the 40m band shortened about 10%, not resonant even on the band.

Not especially good?

The same Smith Chart with the system impedance set to be 300 [ohm].

Rotation by a ladder cable, assuming the characteristic impedance to be 300 [ohm].

The same chart, but the system impedance is 50 [ohm].

This is just one example to see what happens to a dipole tuned for the 40m band.

The antenna is perhaps also usable on the 15m and the 6m bands.

If a dipole antenna is resonant on some frequency, F0, then it is not very usable on the frequency F0/2, because it becomes highly capacitive and the resulting VSWR value will be very high.

The situation is not much improved with a 300 ohm ladder line with the length of 1.5m since it only makes a rotation of 12.6 deg at 3.5MHz on a Smith Chart.

rotation=1.5/(300/3.5)*2*360=12.6 [deg]

With the help of an ATU (ICOM AH-4), it seems that I can QRV on almost all bands with my dipole. I suppose that the part of the trick is the antenna is NOT resonant at any band.

I think I should try to QSO on the 80m band, because it will be my very first one on the band.

If you only have a single display for you PC, you will soon be interested in dual monitors, and then triple monitors, and so on and on. Monitors are like your paddles, and they proliferate autonomously regardless of your intention.

This is my first trial to use a monitor arm, which is now clamped on my new wooden rack. As soon as either of the two monitors proliferates, maybe on one of the long nights when there are no DX signals on the band, I will have a triple monitor system.

I always use water-based paints, because they are easier to handle.

You don’t like the color? I usually prefer more vivid colors, but this time I thought dark brown is easier on the eyes for long-term operations like for a 48-hours contest.

By the way, do you believe if I say this image is computer generated?

Voilà!

A board is cut only four times, twice horizontally and then twice vertically.

My program, CW Keyboard, originally developed on Unix works fine with Cygwin with a slight modification as follows.

#define  MYRIG    "/dev/ttyUSB0"  <--- for Linux
#define  MYRIG    "/dev/com1"     <--- for Windows

You can share a serial port (ex. ICOM CI-V for controlling your rig) among several applications by using Virtual Serial Ports Emulator.

This is when both Logger32 and HDSDR are running with IC-7410.

I suppose I can also run my program, CW Keyboard, along with Cygwin so that three programs are running simultaneously, which is something I wanted to do for the ease of operations.