sentinal-5
sentinal-5
66 / 4
13th January
13th January
i made this mostly to answer a question from NoVIcE about the spherical vs parabolic shape of antenna reflectors. this type of antenna uses a spherical reflector and you probably have one outside your house if you get sattelite tv.
dish radical communication radio science

Comments

  • FlaxxDK
    FlaxxDK
    16th February
    I feel like using filt with tmp as 9 is better than using glass
  • Trigod
    Trigod
    19th January
    I put emp on the RX xD
  • sentinal-5
    sentinal-5
    18th January
    ID:2237590 hope this answers some questions
  • sentinal-5
    sentinal-5
    18th January
    ehh sort of. a parabola would work best in one very specific position. the benifit of a sphere is it works slightly worse from EVERY direction. so you don't need a tailor made reflector for every single lattitude and sattelite.
  • TheNik
    TheNik
    17th January
    So the sphere in this case is actually just an approximation of a parabola, which works well enough for the short path between the dish and the receiver?
  • sentinal-5
    sentinal-5
    15th January
    TL;DR spherical dish is only good for listening, but you can aim it by moving your reciever within the dish.
  • sentinal-5
    sentinal-5
    15th January
    PortalPlayer if you want to have Tx capability yes you need a paraboloid dish, but for Rx only a spherical reflector is cheaper, works almost exactly as well due to the extremely short distance, and allows for multiple recievers per dish. the Arecibo space telescope is a great example of a spherical reflector, but they use theirs to allow the reciever to be moved against a stationary reflector.
  • PortalPlayer
    PortalPlayer
    15th January
    NoVIcE: small antennae are offset so that the feed horn apparatus doesn't block the signal. They're not common for larger dishes because the shape is harder to manufacture. I don't know what this stuff about them being spherical is about, because spheres don't focus properly.
  • PortalPlayer
    PortalPlayer
    15th January
    Offset feed dishes are still parabolic, they just use the half of the curve on one side of the focus. No way would you use a spherical dish.
  • mccafferty2
    mccafferty2
    15th January
    This is why i love tpt