anything
AirNav RadarBox
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
 


Author Topic: question 2 antennas  (Read 3627 times)

0 Members and 1 Guest are viewing this topic.

vonsmalhausen

  • Hero Member
  • *****
  • Posts: 733
question 2 antennas
« on: January 08, 2009, 03:41:28 PM »
hy, is there a way to connect 2 antennas to 1 RB box ?
i ask this 'cause for the moment i have to choose between placing my aerial facing north, ore south, resulting in complete different coverage.
if there would be a way to conect a second antenna to my RB, this would help me a lot.

Fenris

  • Guest
Re: question 2 antennas
« Reply #1 on: January 08, 2009, 03:48:52 PM »
hy, is there a way to connect 2 antennas to 1 RB box ?
i ask this 'cause for the moment i have to choose between placing my aerial facing north, ore south, resulting in complete different coverage.
if there would be a way to conect a second antenna to my RB, this would help me a lot.

Unless the two antennas have perfect hemispherical patterns, however you combined them together you would get cancellation between signals received on both simultaneously at certain positions. I suspect you would lose more than you gain this way.

vonsmalhausen

  • Hero Member
  • *****
  • Posts: 733
Re: question 2 antennas
« Reply #2 on: January 08, 2009, 04:04:43 PM »
thanks for this very quick answer :)
well, looks like i'll have to make the best of it as it is, till i'll install a external antenna

CoastGuardJon

  • Hero Member
  • *****
  • Posts: 1178
  • Mullion Cove, Kernow --- sw Cornwall UK.
Re: question 2 antennas
« Reply #3 on: January 08, 2009, 09:10:56 PM »
hy, is there a way to connect 2 antennas to 1 RB box ?
i ask this 'cause for the moment i have to choose between placing my aerial facing north, ore south, resulting in complete different coverage.
if there would be a way to conect a second antenna to my RB, this would help me a lot.

Unless the two antennas have perfect hemispherical patterns, however you combined them together you would get cancellation between signals received on both simultaneously at certain positions. I suspect you would lose more than you gain this way.


If you've got 2 antennas available (I wouldn't buy another just to try it!), it's got to be worth trying a T-piece adapter - suck it and see! - and see what shows on the polar diagram, provided they're more than the wavelength apart (27/28mm), you may be able to avoid the out of phase signal cancellation effect.   Just for the fun of it tonight, I tried using a Cadbury Roses tin lid as the ground plane for the standard twig, instead of the CD size one provided - did it make any difference, no, but it's fun trying.    Sometimes a bit of experimentation can pay dividends and contradict the laws of physics.........let us know what you find out.

Afterthought, Watson are introducing some co-axial splitter switch boxes, with 2, 3 or 4 connections - no idea of how much they will be though, in-line BNC or N-type connectors would enable quick and easy connect/disconnect with a patch lead going to an SMA plug for the RB, without putting unnecessary strain on the RB ae socket.
« Last Edit: January 08, 2009, 10:01:13 PM by CoastGuardJon »
ANRB :  AOR AR8000 : Icom R-7000 : Icom IC-R9000 : JRC NRD-545 : OptoElectronics Digital Scout and OptoLinx Interface; Realistic Pro-2005 : UBC 800XLT - listed in alphabetical order, not cost, preference, performance or entertainment value!

bratters

  • Hero Member
  • *****
  • Posts: 935
Re: question 2 antennas
« Reply #4 on: January 08, 2009, 10:25:00 PM »
I've had a crack at this but the results were not up to much. I certainly got better reception from the "blind" side of my house (north) with the second aerial but there was a reduction in the overall number of signals. ie a loss of some signals from the south.
As south for me is where most of the action happens and north is to a large degree limited by the peak district and the Penines, I have shelved the project. A roof aerial is the answer - soon I hope.

One new trick I tried is mounting the RB aerial on the outside of my double-glazed upstairs windows. This really increases signals and is simply achieved by sticking a twin suction cup soap dish on to the glass pane as high as possible. (99p from Ebay).
I take the aerial in when it rains but otherwise it works a treat.

Fenris

  • Guest
Re: question 2 antennas
« Reply #5 on: January 08, 2009, 10:31:54 PM »
I take the aerial in when it rains but otherwise it works a treat.

A clear plastic bag over the whole assembly should avoid any problems from rain.

vonsmalhausen

  • Hero Member
  • *****
  • Posts: 733
Re: question 2 antennas
« Reply #6 on: January 09, 2009, 09:50:57 AM »
many thanks for all these answers to my question :)