VideoAerialSystems

Page 2 of 2 FirstFirst 12
Results 11 to 19 of 19

Thread: dipole on ezuhf diversity

  1. #11
    Engineer for Jesus Christ IBCrazy's Avatar
    Join Date
    Mar 2011
    Location
    Amherst, VA
    Posts
    7,352
    ^This is going to sound odd, but you really need to imagine a Yagi antenna to understand this. What happens is that one dipole acts as a reflector to the other and together they form a 2-element Yagi. Of course the location of the dipoles is critical to operation, so a "shot in the dark" is likely not going to yield good results.

    -Alex
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  2. #12
    Quote Originally Posted by IBCrazy View Post
    ^This is going to sound odd, but you really need to imagine a Yagi antenna to understand this. What happens is that one dipole acts as a reflector to the other and together they form a 2-element Yagi. Of course the location of the dipoles is critical to operation, so a "shot in the dark" is likely not going to yield good results.

    -Alex
    Not trying to argue with you Alex but after you seen this 2 di-pole installation on his multi you said " ^Great installation! On a first glance you are actually increasing the gain of the dipoles by positioning them that way. Good work!
    -Alex
    So your saying now " You were wrong?" and we should not use two di-poles side by side? You told me yourself it's OK to do this, and running two coil -loaded side by side is better then two monopoles that's why I ordered your Semi Rigid & Coil loaded. My head hurts man cause I really don't understand what your saying now!!! We should not have 2 dipoles together in our multi copter applications now Alex??
    Last edited by ZACATTACK; 23rd December 2014 at 10:23 AM.

  3. #13
    Engineer for Jesus Christ IBCrazy's Avatar
    Join Date
    Mar 2011
    Location
    Amherst, VA
    Posts
    7,352
    ^ I think you are missing what I said. That particular installation has the proper distance between the two elements so it is not destructive. However, if making a blind guess, you could end up with detrimental effects. The distance between the dipoles should be between 1/5 and 1/9 wavelength in order to not be destructive. The coil loaded dipole is not nearly as susceptible to this issue, though.

    A coil loaded dipole and a semi-rigid dipole together are ok. Off the top of my head separation between them should be 3.5 - 4" if both are vertical for best results.

    That said, multicopters (especially minis) are usually best suited with a standard receiver with only 1 antenna. While diversity can mitigate issues with polarization and such, generally the installation issues on a multicopter are more severe than problems the diversity could help.

    -Alex
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  4. #14
    Navigator
    Join Date
    Apr 2013
    Posts
    344
    Alex,

    How is this setup?

    Is that ok to use, I placed those during my build

  5. #15
    Quote Originally Posted by IBCrazy View Post
    ^ I think you are missing what I said. That particular installation has the proper distance between the two elements so it is not destructive. However, if making a blind guess, you could end up with detrimental effects. The distance between the dipoles should be between 1/5 and 1/9 wavelength in order to not be destructive. The coil loaded dipole is not nearly as susceptible to this issue, though.

    A coil loaded dipole and a semi-rigid dipole together are ok. Off the top of my head separation between them should be 3.5 - 4" if both are vertical for best results.

    That said, multicopters (especially minis) are usually best suited with a standard receiver with only 1 antenna. While diversity can mitigate issues with polarization and such, generally the installation issues on a multicopter are more severe than problems the diversity could help.

    -Alex
    Alex, as usual, thanks for clearing this up... All the best throughout the Holidays & Merry Christmas to You, Marc and all the VAS staff members.

  6. #16
    Engineer for Jesus Christ IBCrazy's Avatar
    Join Date
    Mar 2011
    Location
    Amherst, VA
    Posts
    7,352
    Quote Originally Posted by yappy View Post
    Alex,

    How is this setup?

    Is that ok to use, I placed those during my build

    Your spacing and orientation looks good to me.


    -Alex
    If it is broken, fix it. if it isn't broken, I'll soon fix that.

    videoaerialsystems.com - Performance video piloting

  7. #17
    Hey Alex,


    Would it make any sense to use 2 dipole antennas having one vertically polarized and the other horizontally polarized for example vertically at the wingtip and horizontally along the wing in front of the aileron, kind of like this --|


    Nic

  8. #18
    Navigator Radius's Avatar
    Join Date
    Dec 2013
    Location
    Down Under
    Posts
    348
    Forgive this hijack but since we are on the topic of dipoles and mounting, should the VAS dipoles be mounted in a certain direction given a particular orientation? What I mean is if I have both transmitter and receiver antenna in vertical orientation, does it matter which end (is that the element??) of the dipole is pointing up or down?

    Thanks


    Sent from my iPhone using Tapatalk

  9. #19
    Navigator
    Join Date
    Jun 2012
    Posts
    830
    pretty sure it doesnt matter , never worried about it with mine and had no issues

Similar Threads

  1. Soldering a monopole to create a dipole, Diversity RX
    By Jeff Troiano in forum ImmersionRC
    Replies: 63
    Last Post: 18th October 2014, 04:35 AM
  2. EZUHF Rx and dipole antenna mount
    By gatorb8 in forum RC TECH
    Replies: 11
    Last Post: 11th March 2014, 09:58 PM
  3. Dipole antenna length for ezuhf diversity rx
    By gauravag in forum ImmersionRC
    Replies: 10
    Last Post: 13th December 2013, 02:31 PM
  4. EzUHF Dipole...
    By MrBob6939 in forum ImmersionRC
    Replies: 13
    Last Post: 28th August 2013, 03:56 PM
  5. Longest range flown on EZUHF Lite w/DIPOLE??
    By Scotttu in forum ImmersionRC
    Replies: 10
    Last Post: 6th March 2013, 04:17 PM

Posting Permissions

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