26 February 2010

ROS - A new digital mode

ROS, developed by José Albert Nieto Ros, is a new digital mode under test. Using spread spectrum and 1 or 16 Baud signalling rates it is designed to cope with disturbancies, low level signals, meteor scatter and moon bounce says José. He claims that receiving signals down to -35 dB (!) with 1 Bd signalling rate and -30 dB (!) with 16 Bd are possible. Today I tested 16 Bd reception on 14.1011 MHz. My set-up is shown above with the PC microphone close to a Yaesu FT-857D.

This PC screen dump shows that I did receive PA0JMK in The Netherlands calling YU1RP in Yugoslavia. Unfortunately the vertical screen resolution of my mini-PC is not large enough to show the waterfall part of the ROS GUI. ROS home page from where you can download the software, instructions etc. is here and a video is here. The ROS mode has caused som stir as it occupies a large bandwidth of 2.2 kHz in the HF bands. The mode has become  forbidden to use in the U.S. because of the spread spectrum part of it. Read more about it in G4ILO´s blog. In K3UK´s Sked Page (digital section) you can follow what is going on with testing the ROS mode.

This screen dump shows ROS traffic this evening on 7.050 MHz.

RTTY with iPhone/iPod Touch

Luca IW2NDH has done it again! First he developed an app for PSK31 and now after one month of hard coding and debugging work also an app for RTTY The app is called IRTTY and I just tested receiving on 14.080 MHz with my iPod Touch´s external microphone placed near a Yaesu FT-857D transceiver. See screen dump above. Read here about IRTTY, which also can be used for transmitting RTTY.
Here is a short video showing my receive test.