Announcement

Collapse
No announcement yet.

best antenna

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

  • Originally posted by Oblivian View Post
    Did you cut the top of the antenna down and put it on a can?

    I can't make that decision from this side of the world. All those commercial ones are far too expensive in our local value.
    But a DIY from wire to test may be a cheaper investment to try. Many use home-made and have good range.
    Do I need a filter?
    Here is my data capture record
    Screenshot 2021-09-17 195508.png

    Comment


    • Originally posted by raptor22 View Post

      Do I need a filter?
      Here is my data capture record
      Screenshot 2021-09-17 195508.png
      Yes you do need a filter. Heavy mobile phone signal present in GSM850 band.

      Optional: You may conduct this scan also. It covers full band of DVB-T (24 Mhz to 1800 Mhz)

      ​​​​​​In thread "Do I Need a Filter":
      OPTION-4:
      DVB-T plugged into Windows Computer - Using GUI Spektrum.exe
      Last edited by abcd567; 2021-09-18, 01:13.

      Comment


      • Originally posted by abcd567 View Post
        Same wire data as above, simulated in software MMANA-GAL, gives Gain = 7.35 dBi, & very high SWR = 133 !!!!!!

        Which software to trust????

        Wire dia = 3mm
        Gap between stub wires =6 mm (center-to-center distance between stub wires = 1.5 mm + 6 mm + 1.5 mm = 9 mm)
        Optimum cable tap position = 45 mm from open end (or 69 mm -45 mm = 24 mm from shorted end)


        [ATTACH=CONFIG]4509[/ATTACH]. [ATTACH=CONFIG]4510[/ATTACH] . [ATTACH=CONFIG]4511[/ATTACH]

        I used 3.5mm diameter copper wire with 6mm spacing, built the Franklin antenna according to your size, and tested it with a 50ohm feeder. The resonance point is 1080MHz, and the SWR is as high as 3 at 1090.

        Can you tell me where there might be a problem?

        Comment


        • hello gentleman...
          i would like to show you my results of my development because of antennas. Years ago I started this development because of the unreliable ADS-B data during flying sharp u-turns, curves.
          The ads-b signal is generally vertical polarized. During flying curves the antenna is not vertical. Rod antennas and all other antennas on the market have all a vertical polarization.
          To avoid that problem I developed a new antenna which is very tiny, has a perfect pattern, can be used as sector antenna and no more filter is needed.
          attached I have a video which I made 2 days before ...the result was perfect and follows all simulated parameter ....

          Have fun

          Bill2002

          Sorry I have made comments in german....but you will understand :-/
           

          Comment

          Working...
          X