We have a new competition and as some of you have noticed we have moved the competition dates to the beginning of each month. Congratulations to our previous winner, Gary Cundill (ZS1GAR).

For our new competition we are focusing on the Oscar 100 Satellite, more specifically the reception side of it. Amsat-DL has recently been experimenting with a Multimedia Beacon on the narrowband transponder. The multimedia beacon is part of the High Speed modem designed by Kurt Moraw (DJ0ABR). The high speed modem includes various modes of sending files, pictures and even do digital voice modes using FreeDV. Its a very exciting project and our competition involves getting an Oscar 100 station going and decoding the Multimedia Beacon.

Oscar 100 Narrow Band Reception

To setup a station for receiving Oscar 100 signals you only need a few bits and pieces:

1. Satellite Dish – Make use of the old dish lying in your backyard or get one from your friend who just switched over from DSTV to Netflix 😉 Seriously though, any dish will work. A 80cm dish is probably the easiest to get started, but I’ve had good results with a 60cm dish.
2. LNB – Get a new Ellies LNB from your local hardware store. Don’t worry about modifying it yet to improve the accuracy (that’s a project for another day). The software we will be using has a built-in beacon lock which will minimize the drift.
3. Bias-T – Your LNB needs to be powered with 12v. You can either buy a Bias-T or make your own.
4. SDR – Since we will only be receiving something as simple as a RTL-SDR dongle will work perfectly and you most likely have one lying around. Other SDR devices are also perfectly fine as most are supported by SDR Console. If you are planning to eventually transmit on the oscar 100 then might be worthwhile to get a SDR that can transmit now. The Adalm Pluto SDR is very popular on the satellite.
5. SDR Console – This is the recommended software to use because it has a beacon lock feature that help with an LNB that drifts. Other SDR software will also work though.

Connect all your bits and pieces and get your dish mounted (a temporary mount on tripod works just as well). Use the Dish pointing calculator to point your dish roughly in the right direction. If you used the same Ellies LNB than I did, then you should see some signals around 739.700 Mhz. You are basically looking for the beacons which should have the highest peaks. Once you see the signals you can fine tune the dish position for the best possible reception. You can compare it against the Narrow Band WebSDR.

If you see the beacons and other signals, then congratulations!, you are now receiving the Oscar 100 Narrow Band, tune around and listen to others making contacts. The digital modes section has lots of signals to play with including SSTV.

If you want a more visual tutorial then have a look at this youtube video from Techminds. Also interesting if you are keen on getting the transmit side up and running.

Competition

Ok, so for the competition side we want you to setup atleast a receiving Oscar 100 station and then have a look at decoding the Multimedia Beacon. All the information and frequencies for the beacon can be found here.

For your entry please send us the following information:

1. Information of your receiving station (SDR, Software, Hardware, etc)
2. A photo of you next to your dish
3. Images/Video of the signals you are receiving
4. Tell us about your adventure and what you decoded.
5. (Optional) Bonus points if you decode some of the other digital modes.

You may send your entries to tvdbon at gmail dot com. All entries received will receive a HamsatSA Satellite Hunter Award and all valid entries will go into a draw to win a radio related prize worth R1000 (Previous prize was a 5w 2.4Ghz RF Amplifier). The competition runs from 2022/06/02 to 2022/06/30 and the winners will be announced on the 4th of July. This competition is only open to South African Amateurs.

Rules

• You need to have a valid South Africa amateur license (or be registered as a RAE candidate)
• Competition runs from 2022/06/02 to 2022/06/30
• The judges’ decision is final and no correspondence will be entered into.
• Only South African residents are eligible for prizes, delivery of prizes will only be within South Africa

As always, have fun, send us your stories and build up that Satellite Ground Station 🙂