AirNav Systems Forum

AirNav Radar => AirNav Radar Discussion => Topic started by: catman on June 28, 2009, 06:08:38 PM

Title: Reflection quality
Post by: catman on June 28, 2009, 06:08:38 PM
Hi everyone, another query here

as it stands my antenna on the roof has three spokes, I was wondering if I changed this from the three spokes to a dish would I get a better signal/higher field of interception with receiving planes? I would have thought as much betcause it would be a better reflection to the aerial but just want to run it past you guys?

Thanks
Title: Re: Reflection quality
Post by: EMA on June 28, 2009, 06:53:35 PM
If it is a professionally designed antenna it will make no difference to its performance.
Title: Re: Reflection quality
Post by: catman on June 28, 2009, 08:17:07 PM
Thanks for the quick reply, my query wasn't so much as to the performance aspect to which I think you were relating but more so the range and quality of the signal being picked up? Or is that what you meant.

Thanks anyway
Title: Re: Reflection quality
Post by: EMA on June 28, 2009, 08:34:14 PM
That is what I meant, a disc will make no difference to the signal range and quality.
Title: Re: Reflection quality
Post by: daveg4otu on June 29, 2009, 06:58:15 AM
IIRC - the maximum gain of a Ground plane antenna is in the direction that bisects the angle between the vertical element and the ground plane.... so  if the GP is "spokes" are at , say, 45 degrees  below  horizontal....max gain will be at about
22.5 degrees above the horizontal -

If you substitute a horizontal  metal dish - the max gain  lobe will elevate to 45 degrees above the horizon.

All the above relate to "perfect conditions"- in practice many other factors can have an  effect.
Title: Re: Reflection quality
Post by: malc41 on June 29, 2009, 11:30:50 AM
catman which aerial are you using?
Title: Re: Reflection quality
Post by: catman on June 29, 2009, 03:04:35 PM
Hi,       The antenna came from   water&stanton        RADAR-EXTENDER External antenna for RadarBox  External antenna for RadarBox, 1m long, N type, 6dB gain, 48mm base clamp max.
     
Title: Re: Reflection quality
Post by: malc41 on June 29, 2009, 03:22:32 PM
catman

Yeah the same as I have, just wondered whether you had tried the change or it was just a general enquiry?