My last QRSS Challenge was won by Mike (VK2XMC) and two friends of him : Alan (VK2ZAY) and Iwo. Congratulations to them to have solved this second challenge.
When I built it, I thought this puzzle would be easier than my previous one, but the built-in trap deceived many people. Comments left on the blog were very interesting and I posted some clues to make the challenge progress.
On the screenshot below, you can see the full message transmitted.
G6AVK QRSS Grabber – Full message (bottom)
To reduce the bandwidth used and maximizing the power, I decided to rotate my initial message. I think this simple rotation confused a large part of people concerned. The encoding was very simple and similar to DFCW, wich is one of the most important mode with CW and FSKCW. ‘Triangle’ is another similar mode. G6AVK often transmits triangular symbols over the radioamateur bands. My signal was close to this kind of emissions except I used circles and cross.
There are many possible combinations, but only one gives a coherent result :
The identification of the “bit ly” sequence gives the solution for anyone using the Internet and Twitter. Behind this short URL (http://bit.ly/surwdk), you can see a picture created specially for this second challenge.
The second part of the message looks like a confusing base-2 counting sequence and this was my tiny trap targeted at computer specialists :) Many people tried to solve it as a complex problem, but it was easier ^^ This special arrangement of the second part was possible because it is possible to suggest a sequence in the advanced options of bit.ly.
But why use bit.ly ? Simply because I have to transmit a short message with a small bandwidth. Additional information were located on my website, once the URL was translated.
Well, wasn’t this challenge trivial? :)