Tag: ham

Duga radar

What’s that then? I hear you ask. Well since I became a radio amateur (M0ESB) back in Feb 2003 anything regarding radio has fascinated me.

The Duga or – Russian woodpecker issue of the early 80s has always been an item of interest to me. It was allegedly constructed as a Russian over the horizon early warning system and was replaced in the late 80s when satellite systems took over the early warning mantle.

However it obtained notoriety by creating havoc on the airwaves worldwide for quite a considerable period of time.

This video by a fellow Amateur radio enthusiast M3HHY explains quite eloquently, in 11 minutes what the issue was. Some great photos of this absolutely massive antenna array can be seen in this video.

And whilst we are still here this is what Wikipedia has to say:

The duga system was extremely powerful, reaching over 10 MW, and emitted in the shortwave radiobands. It was given the nickname Russian Woodpecker by shortwave listeners for its emissions randomly appearing and sounding like sharp, repetitive tapping noises at a frequency of 10 Hz. The random frequency hops often disrupted legitimate broadcasts, amateur radio operations, oceanic, commercial, aviation communications, and utility transmissions, resulting in thousands of complaints from many countries worldwide. 

Courtesy: Wikipedia

I hope you find this as fascinating and informative as I have. Radio remains to this day special to me. I’d sooner be listening to it in any form rather than watching a tv. In my eyes or should I say ears, it was the most significant invention ever made, if only Marconi knew back in the 1890s just how important this communication method would become he would have been blown away. It has helped to shape so much, our modern day world, and how we communicate with each other on a daily basis.

Slow scan television on an iPhone

There is a form of amateur radio comms that I enjoy and that is slow scan television. Here’s a basic explanation:

A literal term for SSTV is narrowband television. Analog broadcast television requires at least 6 MHz wide channels, because it transmits 25 or 30 picture frames per second (see ITU analog broadcast standards), but SSTV usually only takes up to a maximum of 3 kHz of bandwidth. It is a much slower method of still picture transmission, usually taking from about eight seconds to a couple of minutes, depending on the mode used, to transmit one image frame.

Since SSTV systems operate on voice frequencies, amateurs use it on shortwave (also known as HF by amateur radio operators), VHF and UHF radio.

Wikipedia

In this Instance below I used a digital transceiver and was pointing the aerial in the general direction of the International space station as it passed overhead on a specific date, when the Russian section of the ISS was transmitting slow scan television pictures as it passed over. I used my iPhone to decode the signal and to produce the pictures, using an app I had installed earlier. This was all part of a day celebrating the anniversary of Sputnik, the world’s first man made transmitting satellite.

My setup was totally mobile and so basic that I just about managed to get partial scans via this technique, see the two pictures below. I was literally sitting in the front seat of my car.

The picture I received from the ISS and my radio

Even though my pictures were not perfect I was still able to supply proof that I received the transmission and as a result was issued with the certificate below from ARISS – Amateur radio on the International Space Station, find out more about ARISS Here: ARISS

ARISS certificate

There are many of these types of events that occur all year round where you can experiment with all types of equipment to make contact with distant radio stations. This is the spirit of amateur radio.