High Frequency Scanning
posted by API_TEAM on 2 December 2012
We used the flagpole in front of the Kiekula to mount 2 wire antennas. They are 20m and 40m end fed dipoles that need no ground (and we are just receiving) but they also handle up to 100W TX power. They used to be build and sold by an amateur operator (AE4LD) but have recently been bought by another company. We've used the antennas all over the arctic and can vouch for their robustness and reliability.  (a little history and technical details on the antennas can be found here) We are using the QS1R Software defined Radio (SDR), with its own software, SDRMAX V and the fldigi (Fast and Light DIgital)software for the decoding. The team spent the evenings bathed in the sounds of the spectrum, and we focused on learning some techniques of digital mode decoding. While much of ham radio consists of SSB voice transmissions, more and more digital encoding is becoming increasingly popular. While not digital, radio's simplest and oldest transmissions have been encoded, CW (or Constant Wavelength) communications remains very popular today and can be heard across the amateur bands. We managed to find some esoteric transmissions like Olivia, THROB, as well as more common BPSK, RTTY and WEFAX transmissions. In fact the WEFAX from Deutscher Wetterdienst, broadcast near Hamburg on 13882.5kHz gave us particularly fantastic results as you can see from a few samples below. We got weather maps detailing icebergs, sea surface temperature, wind and wave size, barometric pressure (which correlated very well with our SINUNI sensor readings) as well as some transmission test images that none of us had seen previously. here is a littile sound sample: WEFAX Sample