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Building an Antenna for Satcom Signals

I built this antenna on a rainy Sunday afternoon, not expecting much from it. Using an online calculator, some 14-gauge solid copper wire, and a piece of PVC pipe, I got to work. I drilled holes in the PVC for the elements, spacing them based on calculations but mostly estimating the insertion depth to ensure somewhat equal lengths on each side. The elements were secured with hot glue. After splitting a coaxial cable and soldering it to the driven element, the antenna was complete. The whole process took less than an hour.

I didn’t get a chance to test it immediately, so I waited until the following weekend. When I finally tried it out, I was very surprised by the results—strong and clear signals!

Purpose and Initial Results

The main reason for building this antenna was to listen to satcom pirate signals and experiment. There are quite a few pirates out there. For instance, one individual constantly transmits SSTV images. I found signals by pointing the antenna in two directions: east-southeast and southwest.

• East-southeast: Likely signals from FLTSATCOM 8 (USA 20) at 54°W.
• Southwest: Possibly signals from FLTSATCOM 7 (USA 7) at 100°W, with voices that sound Brazilian.

Each satellite has multiple channels, but information about them is scarce and often contradictory. Still, it’s fascinating to explore.

2024 Update: New Signals Found

Recently, I took the antenna out of storage but struggled to tune in to the FLTSATCOM satellites—at least, that’s what I initially thought. After further research, I’m fairly confident the new signals came from USA 115 (MILSTAR-1 2). Below are some screenshots of my findings.

I managed to hear voices on at least one channel, though finding voice traffic often feels like pure luck. Using an RTL-SDR dongle and a wideband LNA, I pointed the Yagi back east, where I suspect FLTSATCOM is located. This time, I picked up some transponders, but it’s hard to confirm which satellite they’re from with absolute certainty.

Interestingly, I heard more voices and even some music on the FLTSATCOM satellite this time—no SSTV signals, though. Below are some notes on the transponders I discovered.