Satellite Antennas

 In my never ending quest to continually delay my entry to the CW club, I think my nest hamateur venture will be satellite operations. Multiple satellites with ham radio capabilities orbit the earth at any given moment. One of my favorite youtube channels, saveitforparts, (my new life motto btw), does lots of satellite operations, mainly snooping on commercial, government, and even military satellites. He builds dishes with different low noise amplifiers (LNAs), low noise blockers (LNBs), software defined radios (SDRs), and a bunch of craigslist junk. He just installed a fully automated satellite tracker inside a surplus radome and I could definitely see myself wasting time on similar ventures. 

The uber expensive M2 SATPACK, an example of a commercial egg beater antenna.


To get my feet wet, I thought the best way would be using these ham radio focused satellites. The only equipment I would need is an antenna. Antennas must be circularly polarized due to the way satellites constantly spin. Some people start by building or buying a dualband yagi. These require pointing toward the satellite's approximate location based on signal and tracking it across the horizon. This requires being outside which is perfectly fine, however, I think it would be nice to sit back and work the birds from the comfort of indoors. 

This is where an omni directional, circularly polarized antenna comes in. These get a little tricky due to the phasing to create the polarization, which direction they polarize, and the need for two different frequencies since these amateur satellite repeaters are dual band. 

There is little information out there on how to DIY an antenna like this. I was able to find a reddit post though that linked to an archive.org capture of K5OE's old website where he talks about building omni, CP antennas, colloquially known as egg beaters due to their shape which he adopted into Texas Potato Mashers. I'm posting a link to the archive and the four PDFs I captured here for posterity.

K5OE's website

Egg Beater

Egg Beater 2

TX Potato Masher

TX Potato Masher 2

I'll post a part 2 once I've build at least one of these.

Edit:

Another link to a QFH antenna for NOAA satellites.

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