Talking to your friends using a satellite and cheap radio!

There’s a number of satellites that you can use as an Amateur Radio Operator, for several different things! From sending Amateur TV, to talking with people in other states using the Satellite as a repeater!

For this overview we will stick with FM satellites as they are the easiest to use for a beginner!
We will go over the basic equipment you will need, and how to access a simple FM satellite such as SO-50.

SO-50 is a small satellite with a few payloads, one of which is a Mode J FM amateur repeater experiment.

Unlike traditional repeaters which are usually in the same band, satellite repeaters almost always use an input frequency, and output frequency in different bands.
In the case of SO-50 the uplink is in the 2m VHF band at 145.850Mhz and a downlink in the 70cm UHF band on 436.795Mhz.

There is a 67Hz PL tone (CTCSS Tone) to access the repeater, and a tone of 74.4Hz for 2 seconds is required to ‘turn the repeater on’ so to speak.

There is a decent chance that the satellite will already be active as it is quite popular. I suggest for starters, just tune to the downlink frequency and listen in for a pass using your stock antenna to see if you can hear anything!

There is a number of apps available for tracking satellites, I like to use ISS Detector but I have heard good things about Heavens Above too!

Use the app to check when the satellite will pass over you, and go outside to a large open area, tune to the downlink frequency and just listen!

You will probably want to open your squelch / set it down to 0, as the signal can be quite weak! (The transmitter is over 300-400km away and only 250mw power!)

You want to experiment with moving your radio around a bit, rotate it, try different antenna orientations, see what works best for you, its very much about feel and getting to know how to follow the signal with your ears!

It is possible to transmit to the satellite with your stock antenna, but I would highly recommend investing in a simple dual band yagi antenna, the Arrow 2 is very popular, but can be very expensive to get in to Australia.
I have purchased this one from a local sydney ham and it works well for me! Much more affordable at $135 delivered!

To program your radio for the satellite, there are a few ways to go about it.
If you have a radio that supports split frequency channels, you can program it to TX on the uplink in VHF but listen on the downlink in UHF. How you do this will depend on your radio.
If you have a cheaper radio like a Baofeng UV-5R, you can set the top VFO to the TX frequency, and the bottom VFO to the RX frequency.

Ideally, I would recommend having a second radio to listen in real time, because you can hear how well your signal is getting into the radio.

If the satellite has not been used in some time as it passes over you, it may be necessary to send an activation signal. In the case of SO-50 this is done by transmitting for 2 seconds on the uplink frequency, with a PL / CTCSS tone of 74.4Hz.

Once the transponder is active, and you have everything setup, the hard part is over!

You should be able to angle your antenna towards the satellite in the sky, using your phone app to keep track of where it is, and make contacts via the radio!

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