Vintage digital HF modes

Three nice youtube videos by K2MO, with vintage FSK HF digital modes.

1. LA9OK AMTOR BBS 

 

2. A 20 m PACTOR QSO between KN4YJT (FL) & K2MO (NY)

3. PACTOR I vs. Clover II data transfer comparison

Still active: ROS network on 27635 kHz

Freebanders using ROS, heard on 27635 kHz

The digital freebanders' network on 27635 kHz (11 m), described in a post on 2017-04-06, remains active. The current (July 22) Es openning in Europe allowed strong signals into Greece from Maidenhead locator fields JN and JO. Stations in this extensive network use the ROS MFSK protocol calling CQ or transmitting beacons in various data rates (4, 8 and 16 baud). 

Fortunately PSK reporter supports 11m activities and allows plotting the stations on a map.

DP0GVN: WSPR beacon received on 30m

WSPR beacon DP0GVN (see previous post), located at at the German Antarctic Research Station "Neumayer III", transmits regularly on 30 and 20 m (10 and 14 MHz). 

This evening its weak signal is decoded in Greece. The radio is an IC-706 MkII with a vertical antenna and WSJT-X v1.8.0 software. 

Here are the first three WSPR packets:


1804  -26   0.3   10.140158    4   DP0GVN        IB59     33  12316
1816  -27   0.3   10.140158   -4   DP0GVN        IB59     33  12316
1828  -26   0.4   10.140159   -2   DP0GVN        IB59     33  12316

DP0GVN: WSPR beacon in Antarctica

A few days ago, the ARRL site announced that DARC, in cooperation with two German universities, would install a WSPR receiver and beacon in Antarctica. The receiver is based on the Red Pitaya development board, which can function as an SDR transmitter and receiver. The callsign would be DP0GVN. 

According to the entry in QRZ.COM, DPØGVN is a club station located at the German Antarctic Research Station "Neumayer III" in Dronning Maud Land, Antarctica. The call sign is regularly being activated by station personnel as well as visitors.

This morning I transmitted on 40 m (7 MHz) WSPR with 5W and I was glad to see on WSPRnet that DP0GVN received my signal and reported it to the server. 


Timestamp    Call    MHz    SNR    Drift    Grid    Pwr    Reporter    RGrid    km    az
2018-01-22 02:34      SV1XV      7.040074      -20      -1      KM18ua      5      DP0GVN      IB59uh      12356      191
2018-01-22 02:12      SV1XV      7.040072      -18      0      KM18ua      5      DP0GVN      IB59uh      12356      191
2018-01-21 18:20      SV1XV      7.040074      -26      -4      KM18ua      5      DP0GVN      IB59uh      12356      191

Now I hope to receive their WSPR signal, they transmit with 5W on a vertical antenna, usually on 10 and 14 MHz, but the noise level at my location is much higher.

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).