Page 1 of 3 123 LastLast
Results 1 to 10 of 22

Thread: Antenna, bigger not better?

  1. #1
    Passenger
    Join Date
    Oct 2018
    Location
    Italy
    Posts
    21

    Antenna, bigger not better?

    Hi!
    I've recycled a super-high-quality antenna which was used for a really big outdoor wifi (2.4 ghz) coverage.
    Used hi-end coax cable and nice adapter (to N-MALE).
    Got all the stuff connected and.... poof.... ZERO ADS-B messages per second.
    Usually I get 100 nautical miles range with my finger-sized bundled antenna!! (from Nooelec).
    Photo of this big antenna attached (the cell phone gives you an idea of the scale).
    Any hints?
    Cheers,
    Francesco - T-LIRF54

    20181009_150828.jpg
    T-NOOB-001

  2. #2
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,828
    Seems connector mismatch (Connector on cable v/s connector on Nooelec Dongle).

    Nooelec has either SMA type OR MCX type connector.
    The antenna, designed and built for WiFi, has most likely RP-SMA connectors.

    Both the SMA and RP-SMA look and feel identical and fit with each other, but due to opposite center-pin configuration in RP-SMA, connection of center wire is broken.

    SMA vs RP-SMA.jpg

    EDIT:
    Please post close-up photos of:
    (1) Bundled Antenna showing its connector
    (2) Dongle showing its connector
    (3) The Dongle side connector on antenna cable
    Last edited by abcd567; 2018-10-09 at 15:02.

  3. #3
    Passenger
    Join Date
    Oct 2018
    Location
    Italy
    Posts
    21
    Thank you very much for the reply.
    But no! Connectors are fine as per attached photo

    2018-10-09 16.51.03.jpg
    T-NOOB-001

  4. #4
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,828
    OK, the antenna end N-to-SMA and Cable end SMA are both matching type, so there does not seem to be a problem at the antenna end provided Antenna also has a matching connector to the N-to-SMA adaptor in photo.

    How are the connectors on Nooelec Dongle AND dongle end of Cable? You did not post any photo.

  5. #5
    Passenger
    Join Date
    Oct 2018
    Location
    Italy
    Posts
    21
    Here there are:

    Dongle (from the website):

    nesdr_smart_1_1_1.jpg

    Cable:

    2018-10-09 17.09.07.jpg

    Antenna (w/adapter):

    2018-10-09 17.08.11.jpg

    Thanks a lot,
    Francesco
    T-NOOB-001

  6. #6
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,828
    Adaptors all look OK.
    Now one of the following two things are causing the problem
    (1) Antenna
    (2) Cable

    You can easily check cable by disconnecting cable from WiFi antenna and connecting it to the thumb antenna. If Cable is OK, you will start receiving. In this case, the antenna has a problem. Go ahead and check the cable as above.

  7. #7
    Passenger
    Join Date
    Oct 2018
    Location
    Italy
    Posts
    21
    Good point!
    But the thumb antenna has the far end termination "molded" in the antenna stand! There's no way to bypass it (photo).

    20181009_175208.jpg
    T-NOOB-001

  8. #8
    First officer
    Join Date
    Feb 2014
    Location
    Aldershot, Hampshire. UK
    Posts
    262
    If as you say in your first post it is a 2.4Ghz antenna then it isn’t surprising that it doesn’t work, it is tuned to the wrong frequency and will be designed to only work in a narrow band either side of 2.4Ghz, not 1.090Ghz that ADSB uses.
    Antennas of this type are very narrow band and would be useless outside their designed range.
    FR24 F-EGLF1, Blitzortung station 878, OGN Aldersht2, PilotAware PWAldersht, PlanePlotter M7.

  9. #9
    Captain abcd567's Avatar
    Join Date
    Sep 2013
    Location
    Toronto CYYZ
    Posts
    2,828
    If you have a multimeter or continuity tester, check cable for

    (1) Short between center wire (pin of connector) and shield (nut of connector) - Shoud show open
    (2) Continuity of center wire from one connector to the other i.e. between pins of two connectors of the cable - Should show continuity/short.

  10. #10
    Passenger
    Join Date
    Oct 2018
    Location
    Italy
    Posts
    21
    Hello EGLF1!
    I'm afraid you are right!

    This product fueled my enthusiasm:
    https://www.wimo.com/gp1090-1090mhz-antenna_e.html

    The external similarity made me thought that I'd achieve similar performances!!
    Burnt a little money but - as Alanis Morrissette sung - "you learn!"

    Cheers,
    Francesco
    T-NOOB-001

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •