Ham radio enthusiasts, people looking to borrow their neighbors’ WiFi, and those interested in decoding signals from things like weather satellites will often grab an old satellite TV antenna and repurpose it. Customers have been leaving these services for years, so they’re pretty widely available. But for handheld operation, these metal dishes can get quite cumbersome. A 3D-printed satellite dish like this one is lightweight and small enough to be held, enabling some interesting satellite tracking activities with just a few other parts needed.
Although we see his projects often, [saveitforparts] did not design this antenna, instead downloading the design from [t0nito] on Thingiverse. [saveitforparts] does know his way around a satellite antenna, though, so he is exactly the kind of person who would put something like this through its paces and use it for his own needs. There were a few hiccups with the print, but with all the 3D printed parts completed, the metal mesh added to the dish, and a correctly polarized helical antenna formed into the print to receive the signals, it was ready to point at the sky.
The results for the day of testing were incredibly promising. Compared to a second satellite antenna with an automatic tracker, the handheld 3D-printed version captured nearly all of the information sent from the satellite in orbit. [saveitforparts] plans to build a tracker for this small dish to improve it even further. He’s been able to find some satellite trackers from junked hardware in some unusual places as well. Antennas seem to be a ripe area for 3D printing.
This is really cool, but it would have been interesting to see a comparison of the helical antenna with and without the reflector. I’ve made my own 11 turn L-Band helical antenna that works fine without a reflector (or even an LNA) for INMARSAT at 1545 MHz, so I suspect that the effective capture area might already be similar to the area of this 3D printed reflector. Maybe I’ll do a comparison myself to find out. I’m not sure where the gain tradeoff is between a longer standalone helix and a shorter helix with the reflector. Twice the turns gives theoretically 3 dB more gain, but not necessarily in practice because dimensional errors start to add up. And I’m unclear how to combine the gain of a helix with the reflector gain … I’m sure it’s not linearly additive.
By the way, the end of the video in the link below shows a fairly effective way to get az-el positioning with a couple of relatively low cost servos. It’s not a well done video, but you can get the idea.
https://youtu.be/bIvarNmF7Mc
Now, what I want to see are these made from lunar regolith–perhaps as a reflector pointed at Starship as one of these:
https://en.wikipedia.org/wiki/Solar_power_tower
Now, what I want to see are these made from lunar regolith–perhaps as a reflector pointed at Starship as one of these:
https://en.wikipedia.org/wiki/Solar_power_tower
Upon further thought, I’m not sure how the reflections from the dish properly combine in phase along the length of the helix.
I don’t recommend doing this, sub par performance, far too much effort to make vs performance ratio, poor gain, barely getting a signal from looking at the end images.
You need a filtered LNA like a Sawbird+ GOES, I have very good results having peak SNR of around 14 dB using an RTL-SDR V4
Did you ever try measuring the signal with and without the conical reflector? The helix without the cone would still require the small planar backplane, of course.
I think a well positioned 15 turn helical will work better than this
I agree, and it would be far simpler to build and deploy. The math supports that contention. A 15 turn helical antenna has roughly 15 dBi gain, which equates to a capture area of a circle with a diameter of about 32 cm.
And if you look at t0nito’s reflector, it isn’t parabolic or even spherical, so some of the reflection is missing the 6 turn helix. And I still question whether the reflections from the mesh dish arrive at the various portions of the helix in the proper phase.
The cone doesn’t bounce the signals back to the helix, it’s not parabolic and it’s not a reflector it is a ground plane, a higher turn count in theory does give you more gain but at the expense of the pattern becoming much narrower making it much more difficult to aim, also it will pick up much more noise from the sides, I tried a higher turn count and had worse results.
You can learn more about helicones here:
https://www.researchgate.net/publication/329985554_Design_guidelines_for_helicone_antennas_with_improved_gain