Friday, 30 January 2015


The Automatic Identification System (AIS) is an automatic tracking system used on ships and by vessel traffic services (VTS) for identifying and locating vessels by electronically exchanging data with other nearby ships, AIS base stations, and satellites.
Information provided by AIS equipment, such as unique identification, position, course, and speed, can be displayed on a screen.

An AIS transponder normally works in an autonomous and continuous mode, regardless of whether it is operating in the open seas or coastal or inland areas. AIS transponders use two different frequencies, VHF maritime channels 87B (161.975 MHz) and 88B (162.025 MHz), and use 9.6 kbit/s Gaussian minimum shift keying (GMSK) modulation over 25 or 12.5 kHz channels using the High-level Data Link Control (HDLC) packet protocol. Although only one radio channel is necessary, each station transmits and receives over two radio channels to avoid interference problems, and to allow channels to be shifted without communications loss from other ships. The system provides for automatic contention resolution between itself and other stations, and communications integrity is maintained even in overload situations.

In order to ensure that the VHF transmissions of different transponders do not occur at the same time, the signals are time multiplexed using a technology called Self-Organized Time Division Multiple Access (SOTDMA).

You can watch AIS traffic on the map here:

Saturday, 17 January 2015

Turkish QSL card

I received a QSL card from the Turkish Amateur Radio Club TA2KK. Operator of the 20 m RTTY QSO in August 2008 was Sencer, TA2AHS.


The QTH of the Club station is located in the Asian part of Istanbul.


Monday, 12 January 2015

50 MHz 10 Watt amplifier

I found some info of a 6m amplifier I built in 2007.
It uses a VHF transistor 2N4933. I made the unit in order to give the SEM35 radio 10 Watts out instead of 1 Watt. The PA can only be used in FM and CW.

                                         Circuit 10 Watt PA for 6 m


                                                           Inside view

                                                              Tronser 30 pF 


Saturday, 10 January 2015


EdX offers interactive online classes from the world's best universities. Online courses from MITx, HarvardX, BerkeleyX, UTx and many other universities. Topics include biology, business, chemistry, computer science, economics, finance, electronics, engineering, food and nutrition, history, humanities, law, literature, math, medicine, music, philosophy, physics, science, statistics and more. EdX is a non-profit online initiative created by founding partners Harvard and MIT.

Because there is more in life than radio and electronics a couple of weeks ago I decided to participate in a course called "The violent universe". This course explores the most deadly parts of the universe: white dwarfs, supernovae, neutron stars and black holes. 
Brian Schmidt and Paul Francis astrophysicists at the Australian National University are the teachers.

I learned a lot about astrophysics. For example calculating dimensions and masses of objects in deep space like neutron stars and white dwarfs.
This course gives you a feeling of the huge amounts of energy we are dealing with in outer space. I enjoyed the course a lot. It includes a lot of YouTube movies, mathematical questions and of course the final examination.

Following subjects are discussed during the course:

ANU-ASTRO3x The Violent Universe
Section 1: White dwarf stars
Section 2: Degenerate stars and Quantum Mechanics
Section 3: Dwarf Novae
Section 4: Classical Novae, the Chandrasekhar Limit and Nuclear Physics
Section 5: Thermonuclear Supernovae
Section 6: Core Collapse Supernovae
Section 7: X-ray astronomy and Neutron stars
Section 8: Special Relativity
Section 9: Black Holes

This course takes you about 3 hours of time per week during a period of 10 weeks.
You can do this course any time (self paced).

Sunday, 4 January 2015


The eQSL from Marco, IS0BSR shows the beautiful colours of a sunset.
February 9, 2013 I made a SSB QSO with Marco on 20m SSB.

                                                               Cala Corsara

Sardinia (IS0..) is considered a DXCC entity since the island is geographically seperated
by a minimum of 225 miles of open water from the "parent"  DXCC country (Italy).
This is not the case for Sicily (IT9..) which is seperated with only a few miles from the main land.

Saturday, 3 January 2015

Dimension 4

In order to use digimodes like WSPR or JT-like modes you need an accurate computer time. Dimension 4 is an easy way to synchronize your computer's clock if you're running a Windows-based operating system. I have succesfully used it on PC's with Windows XP and 8. Once Dimension 4 is installed, you can be sure that your computer works with the correct time.

Download the program for free here: