Would You Like a Satellite Dish?

Satellite dishes are a common site these days, although admittedly most of them are Ku- and Ka-band dishes. The older C-band dishes are still around, though, just less frequently in people’s yards. [Greenish Apple] decide to cut the cable and start watching free TV so he built a C-band dish. The trick is, he made the dish out of wood.

The design is the offset type, not a prime focus dish–that is, the electronics are not in the center of the dish but on the side. Wood isn’t particularly good at reflecting RF, of course, so over the wooden skeleton, he used flashing.

The finished project looks distinctly homemade. The diameter of the dish is 108 inches, but due to the flat areas in the dish it performs more like a 36- to 39-inch dish. However, [Greenish Apple] did learn one lesson: When the sun lines up right, the bare flashing concentrates enough heat to melt the receiver. An overcoat of paint fixed that problem.

Of course, you might want to harness the heat. If were going to make a dish, we’re not sure we’d make a C-band dish–there isn’t a lot of unencrypted programming these days. However, the general technique could apply to any┬áplace you need a high gain antenna. Maybe you could even borrow some WiFi.

25 thoughts on “Would You Like a Satellite Dish?

  1. The problem is radio amateurs haven’t gotten the video images to be perfectly clear of interference from those Georgia Satellites.
    That’s right, don’t give me no lines and keep your hams to yourself.

  2. “Petal” Satcom antennas (“Petals” as in petals of a flower) – offset-fed satellite antenna reflectors are long understood. Today you can actually buy them (cheap through very expensive – depending on the application). The design is attractive because the inter-locking petals can be broken down into pieces that are relatively small and/or inexpensive to pack and ship; You end up with a bunch of relatively thin petal panels that stack-and-pack into a compact and easy to ship box or crate, long and narrow is the key (goes well in standard 20/40-foot containers). The end-user unpacks and assembles the shipment and assembles the reflector (and other parts) using simple tools. Are there trade-offs with this type of antenna design? Of-course there are – many. But I don’t have the time as I post here to explain further (sorry). And, just for fun – think about how the petal reflector design may apply to compact antennas launched on spacecraft and deployed once in space ;-)

  3. Have a naked woman stand in the middle of it lying on the water.
    Botticelli’s The birth of Venus!
    The last time I looked even NASA select had moved to Ka band, C band is just like shortwave, just one big pulpit. I have a 10 foot C band dish and receiver for free, but don’t need to be “saved” or polluted by Holeywood. I could aim it across the river valley at Purdue and get almost anything coming out of the EE building! Just one quadrant of it foil covered would make a solar cooker.

  4. Most of the major networks still use C band for their distribution feeds. Drive by your local TV station and see what kind of dish they use. C band is more reliable because it’s less affected by weather and things like “rain fade. Of course C band also requires a much larger dish because of the larger wavelength. The dish he’s built there is way too small for most C band satellite feeds. Nowadays a lot of feeds are using 8psk, 16apsk, and even 32apsk modulation modes. Those type of feeds typically require a much cleaner signal and therefore a bigger reflector. If your really interested in FTA and searching for wildfeeds, you really need at least a 10 to 12 foot dish. You also need a way to search for feeds as a lot of the more interesting stuff are wildfeeds and backhauls. These are signals that are temporary and come and go. Most of these would be things like sporting events, concert, or remote news feeds. Because of the nature of these signals you have to kinda hunt for them. The way to do this is either with a spectrum analyzer or a tuner card that supports “Blind scanning”. Anyway, if you do get into this hobby and manage to find some feeds, don’t go bragging about it or posting what you find on the internet. Doing that is a good way to get these feeds encrypted. Often times when word gets around and it becomes common knowledge that certain feeds are available in the clear, it’s not long before those feeds wind up being encrypted. So, don’t be a blabbermouth.

  5. There used to be a law or FCC rule or regulation in the USA that open air broadcasts of video from satellite or terrestrial transmitters could not be encrypted if the programming contained advertisements.

    IIRC it was in the same legislation that made TVRO (TeleVision Receive Only) satellite receivers firmly legal for us ordinary peons. Yup, the TV networks tried to get them outlawed so they’d have all the control of what people were able to watch.

    This was mentioned in an article in the August 1983 issue of Mechanix Illustrated on how to build your own C-Band dish from scratch. The issue has a cover photo of the dish, built with a hexagonal rim frame of wood with the rest of it being made of pipe, conduit and window screen. The article provided the complete plans and construction details, including tensioning the screen using wire ties to the frame behind it to achieve a parabolic shape.

    Now that was a hack. I wonder if any of the dishes anyone built using that article still exist?

    But at some point in time, the part about commercial containing TV content having to be in the clear must have been altered or repealed. When did it happen?

  6. When I was in Las Vegas in about 1991 or so, I was in a motel across from a local TV studio. I turned on my scanner and found I could pick up their wireless microphones. It was more entertaining listening to the director talk to the “on-air personalities” as they tried to read the news, than the video. My God, that man never shut up. I felt sorry for the overpaid fancy-hair bastards.

  7. A friend of my father did a C band dish around 30 years ago. He told me when he and my father travelled together to buy the receiver, they had told to the seller they are building the dish from scratch. The guy said “you, guys, must be crazy… It’s not a HAM antenna.” Well, the friar from my city helped him with the calculations(in fact, he said it was very easy). The first one worked, but not very well. The second one is still working. Dad told me the old dishes you had to change the signal polarisation by hand. He used to be a satellite dish installer and I was your little helper when I was under 10. Now I’m 30 and we still like to align dishes.

  8. The difference in an offset parabola dish isn’t where the feed is mounted. It’s the shape of the dish. A prime focus dish has the focus of the parabola in the middle of the dish. An offset parabola has the focus offset from the middle, sometimes not even on the dish itself.

  9. My dad used to have a C-band dish back in the 90s. It came with the house. The positioning motor was broken and he never bothered with it but I did. I losened the bolts on the motor just enough that I could turn it by hand but not easily so that the wind didn’t move it much. I would run outside, move it a little, run back in and see if there was a satellite. Once I found one and had it positioned well I would make a mark on the motor’s arm with a hacksaw right next to the bracket so that I could find it again easily. I didn’t live with him but I enjoyed playing with that whenever I went to visit.

    Anyway.. his receiver was weird. At least I think it was weird. Everyone that I knew who had a satellite receiver had a computerized one that worked more or less like a cable tv box. This thing had knobs. It’s been years and I don’t remember what all the knobs were exactly. I think it had a channelized knob for frequency but then two analog knobs one for video subcarrier and one for audio subcarrier. Or.. maybe only audio had a subcarrier knob… There was also a button to chose between horizontal and vertical polarization. Sometimes you could get two channels just by switching the polarization.

    Anway,, playing with these I found more than just tv. There was digital data of course though I guess that might have just been digital TV. But.. I remember finding a lot of morse code. At the time I wasn’t a ham yet but I did know that ham radio satellites are a thing. But… on the same satellite as TV? Was that ever a thing? I don’t think it is now. Why was there morse code on a TV satellite? Does anybody here know? I’m still curious. It wasn’t even a rare thing, there was a lot of it!

    I don’t think it was ham satellites that just happened to be in the same direction as the TV satellites either. Any ham satellite that I have ever been aware of is in a polar orbit. You only get the signal for a few minutes. These signals seemed to stay in one place in the sky.

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