[David Prutchi] has an FTA (free-to-air) satellite dish. This means he can tune and watch freely available satellite television feeds. But this sounds much better than it actually is. There isn’t much that’s broadcasted unecrypted from satellites with the exception of a collection of religious channels. But he still uses the dish by using the FTA satellites to calibrate the alignment, then repositioning it to receive L-Band radio transmissions with his own add-on hardware. In the image above it’s the spiral of wire attached to the dish’s collector.
The satellite transmissions are picked up on the KU-band by an aftermarket horn that [David] purchased for this purpose. To add his own helix receiver he cut a square mounting plate that fits around the horn. This plate serves as a reflector and ground plane, and also hosts the helix connector which picks up the L-band transmissions. He had to be creative with routing the first few inches of the helix but it looks like he manages to get some pretty good performance out of the hardware.
[via Hacked Gadgets]
11 thoughts on “FTA Dish Used To Receive L-band Amateur Radio”
Poor people in the US. In Europe, the satellites are full of FTA stations, especially the 19.2 and 28.2°E positions.
FWIW the author of this article is incorrect. there are a lot of FTA feeds available that are not just ‘a collection of religious channels’. plenty of unencrypted stuff on the KU band. obviously you wont get HBO but there is plenty of free content out there, particularly international programming.
going a step further, the larger the dish, the better. in fact if you have a BUD (big ugly dish) with a c-band LNB, you can get all sorts of feeds. Wildfeeds from live news broadcasts, channels backhauled to local affiliates and sometimes premium HD channels because they do not bother encrypting some of this content (the ol’ security through obfuscation) assuming you cannot either a. hit/find these birds or b. utilize a BUD in your yard in order to get the c-band signals.
i will admit there is definitely more FTA television in europe and asia, but im just wanting to clear the articles inaccuracy up.
L-Band is 40GHz to 60GHz. Highly directional antennae are needed.
I too was confused at first about what he meant by L-band. If you read the article, he’s talking about the 23 cm ham band (roughly centered around 1200 MHz). L-band refers to a couple of different bands depending on who you talk to.
oops, more like 1275ish.
The most commonly understood RF frequency range for L-band is 1-2 GHz (IEEE designation). Just to be contrary, the EU calls 40-60GHz L-band. The Antenna referred to in this post is running at 1296 MHz. Astronomers break up the optical and infrared bands and designate the segments by letters. So there is an L-band for infrared and an L-band for optical (off-hand I don’t know the wavelengths).
Also, antenna directivity is dependent not only on frequency, but aperture size as well.
L-band as it’s generally referred to with regard to satellite receivers is 950-2150 MHz. It’s the signals that come out of your LNB and travel down the coaxial cable to your receiver. This way if you want to receive different bands, like C, Ku, or Ka, you simply use a different LNB with a different local oscillator. The LNB uses a mixer along with a local oscillator to produce L-band frequencies which travel down the cable to the receiver. This way the receiver only has to deal with L-band signals and not worry what the actually frequencies coming from the sky are. It also makes it easier to use cheap RG6 cable to connect the dish to the receiver.
Anyway, I think this is the “L band” he’s referring to here as the other “L band” would require a helix of much different dimensions since the wavelength would be much smaller in comparison.
Impressive build, but nothing new or unique in ham radio circles. We hams have been re-purposing satellite dishes for as long as they have been around.
Still, very nicely done.
Paint an 8 foot or larger BUD with one of those super shiny mirror chrome paints* clear coat and you have a very nice collector for solar thermal experiments. Stripping the paint from a solid aluminum dish then polishing and clear coating may also work, but polishing something that big would be a time consuming job.
Just make sure whatever you use for cooling what you have at the focus doesn’t quit or it’ll melt rather quickly.
*Spaz Stix Ultimate Mirror Chrome or Alsa MirraChrome. Another option would be Spectra Chrome which is actually silver plating just like is done on mirrors. People with more money than brains have entire cars coated with that.
If all you can find is religious channels, you are not doing it right.
My mpeg4 receiver gives me a LOT of programming. Plus all the Soccer you can eat!
Plenty of non-religious channels out there that aren’t religious but they tend to have a political bent of one sort of the other. What the for pay SatTv service don’t want you to know is that much of what you receive from them isn’t encrypted especially the music channels. Check your favorite channels website to see if it offers a FTA channel.
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