Arecibo Observatory Ionospheric Heating Campaign

Reception on 5125 kHz using Icom IC-706 Mk II and Spectran at 04:23 UTC

 In the morning hours of July 31, 2017, I finally managed to receive the signals from Arecibo Observatory in Puerto Rico on 5125 kHz. The signal at my location peaked at S5-S6 using a vertical HF antenna, not tuned to the frequency.

 

Reception on 5125 kHz using Perseus SDR at 05:28 UTC

These signals, transmitted during the past week on 8175 and 5125 kHz, were a HAARP-line experiment, using the huge Arecibo spherical reflector. The TX power was 600 kW and the estimated ERP was 100-200 MW ! The current setup is described in a paper titled "The New Arecibo HF Facility Dual Array Cassegrain Antenna" by J. K. Breakall of Penn State University (available on-line).

Waterfall of Perseus SDR at 05:28 UTC

In parallel to direct off-air reception, I cross-checked with the WebSDR receiver at the University of Twente, to ensure that I did not receive a spurious signal.  On July 25, 2017, starting at 16:15 UTC I received an unidentified steady carrier on 8175 kHz, which was not reported by anyone else and I could not hear on the WebSDR site.

Possibly Arecibo transmission on 8175 kHz, on July 25, 2017, 16:39 UTC

The experiment was advertized in many on-line resources, like the ARRL web site, the Ham Radio Science Citizen Investigation (HamSCI) site, the UDXF mailing list and numerous twitter posts. Accordig to other listeners, at the end of the experiment Arecibo transmitted a SSTV signal in AM mode; unfortunately I could not remain in the shack this late. Other stations in Europe, however, reported good reception of the SSTV signal.

According to ARRL, reception reports shall be confirmed with QSL cards direct via W3HNK.

Makers' stand in RAAG Hamfest 2017

Assembled LSF II model rocket

LSF-II model rocket with diassembled payload

AZ-EL antenna rotator

Last week RAAG organized the 2017 Athens Hamfest in Peristeri Exhibition Centre. Between many commercial and boot sale stands, I noticed the following interesting exhibitions:

1. A stand by the Greek CB group "ΠΑΣΥΧΕΡΑ" (18SV000), now fully active after the recent liberalization of CB radio in Greece.

2. A nice stand by a makers group, with LSF-II model rockets, home-made 2 axis antenna rotators using 3d printed components, and other goodies.

ROS network on 27635 kHz

ROS software window

The recent Sporadic E (Es) openning in Europe, very prominent on 50 MHz, allowed also extensive freeband digital operations on 11 m, 27635 kHz. The freebanders use exclusively the ROS protocol, which is designed and implemented by Jose Alberto Nieto Ros EA5HVK. They use callsigns like 13RF441 or 14OCF77, where the first numerical digits indicate the country of the stations, according to the Alfa-Tango Prefix and divisional QSL list. The stations follow procedures very similar to ham radio, especially like the ones used on PSK31 frequencies.

Freebander ROS activity on PSK Reporter

The freebander ROS activity is also supported by the on-line real time map logger PSK reporter, most operators and some listeners upload regular reports.

ROS is a very efficient MFSK protocol, suitable for low S/N ratios, which is also used in the amateur radio bands, especially on 14103, 28140 and 50245 kHz.  

The current version of the program is 7.4.0 and it is available for free on https://rosmodem.wordpress.com/ along with OPERA beacon software, also developed by EA5HVK. Instructions for system and software setup by G0HDI are available on the Welcome to GoHDI's ROS mode page. Technical information about the ROS protocol is described in the SIGID Wiki. Genenally setup is very easy with automatic tranceiver discovery and identification over serial port CAT links. It allows the definition of multiple system profiles, in order to support multiple radios etc, similarly to WSJT-X.

WSPR beacons on 474 kHz

Map display of WSPR beacons heard on 630 m, from wsprnet.org

Early this morning I switched my radio on 475.6 - 475.8 kHz in the 630 m WSPR band for the first time. I conencted my HF vertical antenna directly to the Icom IC-706 MkII radio, without any matching, filtering or tuning. Only one station showed up, IW4DXW JN64 (1147 km).

WSPR beacons on 1.8 MHz

Map display of WSPR beacons heard from wsprnet.org

Last night I left my radio on 1838.0 - 1838.2 kHz in the 160 m WSPR band. I conencted my HF vertical antenna directly to the Icom IC-706 MkII radio, without any matching or tuning. I received a number of European WSPR beacons, the most distant being G3ZJG in IO92 (2497 km) and RX3DHR in KO94KS (2187 km).