AMSAT-BR QO-100 FT8 QRPp Experiment

AMSAT-BR Logo and Dish AntennaAMSAT-Brazil is organizing a reverse beacon FT8 QRPp experiment/contest via the QO-100 geostationary amateur radio transponder.

The first 10 spotted stations with lower SNR will receive a Certificate of Accomplishment.The dead line will be May 1st 2020. To qualify, the SNR must be lower than -18 dB (as measured by the ft8 decoder). The receiver will be active on Saturdays and Sundays from 12:00 UTC to 24:00 UTC and will be tuned to 10.489540 GHz with a 3.5 kHz bandwidth. All stations calling CQ will be logged.

The objective for the project is to incentive low power experimentation through the QO-100 narrow band transponder. Stations participating in the experiment are welcome to send a brief description of their setup, including information about RF power output, hardware and software setups, antenna type and gain, photos, etc. to the email address
py2sdr at gmail dot com.

73, Edson PY2SDR

You can listen to the QO-100 transponder downlink online at https://eshail.batc.org.uk/nb/

QO-100 information https://amsat-uk.org/satellites/geo/eshail-2/

Caution Urged in Using High Duty Cycle Digital Modes via Satellite

Amateur Radio Satellite FO-29

Amateur Radio Satellite FO-29

A report in ANS-288 discussed an experiment operating with the WSJT-X FT8 digital mode via satellite. Satellite operators have gained more experience with this mode over this past week.

As a result of on-the-air observation other satellite users planning to try FT8 or MSK144 modes via satellite are encouraged use caution using these modes and possibly avoid their use completely in light of problems.

Dave, KG5CCI wrote, “He noticed a very hard time getting into the transponder. The pass was nearly overhead, and the 3w-4w that is normally sufficient was barely cutting it. I also noticed it was ‘up and down’ alot, whereas some moments it was easy to get in, then it would be nearly impossible. There were also pockets of ‘noise’ all over the transponder, that sounded somewhat digital, but I just couldn’t place them.” Further investigation revealed that an MSK144 signal in the transponder passband was causing the problems.

Matthew, NJ4Y noted, “Experimentation isn’t the problem, too much power is. It’s bad enough on SSB, worse with CW, and killer on constant duty cycle modes like FT8.”

To gain a full understanding of the situation readers are encouraged to follow the amsat-bb message thread which can be accessed at http://www.amsat.org/pipermail/amsat-bb/2017-October/064896.html

Source: AMSAT News Service http://www.amsat.org/mailman/listinfo/ans