This is my first post, so please be kind.
First, to contact a satellite, you'll need a good antenna. A basic option is the JYR antenna (available on Taobao for around 280 yuan), along with a suitable handheld radio (such as the Qiansheng UV 2plus, which has an output power of nearly 10 watts). Alternatively, you could use the Baofeng DM5R and install the OpenGD77 firmware to enable automatic Doppler frequency adjustment. In addition, you'll also need a smartphone to track the satellite and calculate the Doppler shift.
Regarding the software, I recommend two options: the first is Look4Sat, and the second is "Xing" (developed by BI3OJW), which can be downloaded directly from many amateur radio satellite groups. Please note one important thing: the satellite ephemeris (star charts) need to be updated weekly.
Here's a brief introduction to the Doppler effect. The Doppler effect occurs when an object is moving rapidly. When a satellite moves from its closest approach to its furthest, the frequency of the signal it transmits decreases gradually, and this decrease isn't linear. If we want to transmit signals to a satellite, we need to adjust the frequency first to a lower value and then increase it. The typical Doppler frequencies for U-band are 25 kHz, while V-band is 3 kHz. To ensure successful communication, it's best to store the channel directly in the radio. Specific frequencies will be provided as attachments to this post.
Once all preparations are complete, we can proceed to find a suitable open space. With the equipment ready for the satellite's arrival, we can use the main beam of the antenna as a rotating axis to adjust the polarization for receiving or transmitting signals.
As the satellite passes overhead, we might hear some amateur radio operators (hams) making QSOs. At this point, I adjust my antenna and then simply transmit my call sign (since the satellite's transit time is usually only about 10 minutes, so it's important to keep the contact as short as possible). For example, if I am communicating with BH7FFR, here's a typical conversation:
PBV: BI4PBV
FFR: BI4PBV BH7HHR 59 73
PBV: BH7FFR BI4PBV 59 73
A careful observer might notice that almost everyone on the satellite uses the same call sign, "59," regardless of whether the signal is good or bad. This is due to some unspoken rules and conventions, so there's no need to worry about it too much.
A typical communication process generally follows this sequence:
Tonglian Video
As for the specific details, I may provide further comments later on, so please stay tuned.
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