Announcement

Collapse
No announcement yet.

QUICK SPIDER - No Soldering, No Connector

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    It doesn't matter the cable RG6 is 75 ohm?

    Comment


    • #32
      Originally posted by apeiron69 View Post
      It doesn't matter the cable RG6 is 75 ohm?

      No, it does not make any difference as the DVB-T dongle has input impedance of 75 ohms. The DVB-T is designed for TV reception, and the TV system uses 75 ohm.

      Even if the dongle was 50 ohms, in receiving situation like we are, the mismatch between 50 and 75 ohms does not cause an appreciable loss in performance (the SWR for 50 to 75 transition is 1.5, and mismatch loss is only 0.177 dB). As in receiving scenario, the power levels are in milli or even micro watts, which are easily compensated by front end circuits of the dongle.

      For transmitting equipment the 50 to 75 ohm mismatch should be avoided to reduce reflected power, as the power levels involved are in watts or tens of watts or even hundreds of watts.
      Last edited by abcd567; 2020-06-15, 14:48.

      Comment


      • #33
        QuickSpider Ver2

        Part -1: Design



        Designed By Computer Simulation



        V-Spider-Horizontal-Radials-3.png


        V-Spider 84-45-141-SWR.png

        V-Spider-84-45-141-Radiation-2D.png


        V-Spider-84-45-141-Radiation-3D.png






        Comment


        • #34
          QuickSpider Ver2

          Part -2: Building & Testing of Prototype



          Comparison of V-Stub QuickSpider with Bench Mark Antenna (Flightaware Antenna)


          FA Antenna >> 30cm RG316 pigtail >> FA light Blue Filter >> FA ProStickPlus (blue) >> OrangePiPC
          V-Stub Antenna >> 100cm RG174 pigtail >> Radarbox24 FlightStick (green) >> RPi4

          Flightaware 26" Antenna on left side of window
          V-Stub Quick Spider on right side of window
          Horizontal spacing between antennas = 30 cm

          NOTE: The paper behind V-Stub was placed while taking snapshot, as without it the thin wire of V-Stub was not clearly visible in the photo.

          V-Stub with FA.jpg



          Pilot Antenna's Dimensions & SWR


          V-Spider-Pilot-Built and SWR-3.png


          Comparison: Number of Aircrafts Tracked

          V-Spider-Comparison-Aircrafts.png



          Comparison: Message Rate

          V-Spider-Comparison-Rate.png




          Comparison: Maximum Range

          V-Spider-Comparison-Range.png



          Last edited by abcd567; 2020-10-17, 19:53.

          Comment


          • #35
            V-Stub on Mag-mount Base (placed on a metallic plate)

            V-stub wire collinear-35pc-E2.jpg

            Comment

            Working...
            X