20 August, 2014

Digital Signal Processing

The Norwegian-language "The road to the international radio amateur license" came off the press this June. It is based on the RGSB International Amateur Radio Examination Manual from 2006, which RSGB graciously allowed us to use.

But the translation has been adapted on several topics. One example is the chapter on propagation due to the need in our country for more emphasis on propagation in polar regions and in mountainous terrain. Another is a completely new chapter on digital signal processing.

15 August, 2014

New gadget measures negative resistance

If you are like me, you appreciate electronic gadgets with dials and displays. So when I discovered this "USB detector",  I thought to myself that I really always wanted to know the voltage as well as the current consumption of my USB devices. And since it is more or less impossible to connect a multimeter, this is exactly what I need.

The device fully satisfied my curiosity. Actually one surprising result was that the charger for my Samsung Galaxy Note 8 has a negative output resistance.

07 August, 2014

WSPR on 5 bands

For the first time ever I have been spotted on all the five bands that my Ultimate3 QRSS/WSPR kit (G0UPL design) is transmitting on. This is after 2-3 days of transmitting.

Right now I am using the beacon for discovering if the bands should open up on 24 and 28 MHz. The other three bands, and especially the 14 MHz band, serve as references to tell me that the transmitter is working. My antenna is not so optimal so I would be surprised if I am spotted far outside Europe. It is an end-fed 5 m long half wave vertical dipole which isn't too bad for 28 and 25 MHz, and probably not very good at all on 21, 18, and 14 MHz.

02 August, 2014

Nice radio-related stamp

A few weeks ago I had one of my rare visits to the post office. As I was waiting, I saw a display of a new series of stamps and I just had to buy the one shown here. What caught my attention was not really the artist, but rather the Kurér portable radio.

The stamp was of course not about the radio but was issued in commemoration of the 100 year anniversary of the birth of Alf Prøysen. The English Wikipedia page has this to say about him: