Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Ground waves?

  1. #1
    Professional
    Join Date
    Aug 2009
    Posts
    1,147

    Default Ground waves?

    This is probably a question for someone like Jimbonzz. I have used the search function and came up empty handed.

    I was wondering if microwaves propagate in ground waves also?
    The reason I ask is because I have a sti-r+ mounted about 8 inches off the ground behind a bumper and a redline mounted high in my windscreen and my sti-r always alerts before my redline. Every time.

    I done a little experiment and turned off X and Ka bands on both detectors to make things even and the remote mount always wins on K band or any band for that matter.

    Which brings me back to my ground wave theory. Does it hold any water?

  2. #2
    Good Citizen
    Join Date
    Apr 2008
    Location
    next to a polar bear and hockey puck
    Posts
    188

    Default Re: Ground waves?

    MEM-TEK had a similar idea of the hood helping to reflect some radiation to the detector, thus increasing alert time.

    I'll second your motion that I believe the ground, terrain in general, will help concentrate a signal help out the detector. For instance, have you noticed that if a LEO is shooting radar into or in a valley you get an alert much sooner then if you're on a flat or over a hill?

    Just an observation, I have no numbers or measurements to follow up.

  3. #3
    Old Timer
    Join Date
    Jun 2005
    Location
    New Hampshire
    Posts
    6,806

    Default Re: Ground waves?

    Your windshield will attenuate the signal slightly. Some are worse than others, those with metallic tints or conductive defogging systems can cause real problems with RDs.

    But, even with a normal windshield, you'll get at least some better sensitivity from a detector mounted externally.

    Another possibility is your STi-R+ happens to be a "hotter" unit than your Redline. They use the same platform, so, in a perfect world, they should have the same amount of sensitivity, but manufacturing variances and component tolerances make some units perform better than others.

    Are you running both in Highway mode? Are you using Ka-band segmentation on the STi-R+?

    I bet in heavier traffic the Redline has better reception since it will have a better "view of the road". Do you find this to be the case?
    Last edited by kpatz; 06-03-2010 at 08:42 AM.
    If I'm passing you on the right, YOU are in the wrong lane!

    If speed kills, how come I'm still alive?

    Active Countermeasures: V1 3.858, Escort Redline, Beltronics STi-R+, LI Dual 7.1x CPU/8.7 Heads (front)
    Other/Backup Countermeasures: V1 3.813 (loaned to friend), Beltronics Pro RX65 M4 6.3
    Vehicle: 2002 Audi A4 1.8T Quattro
    LEO Toys: Kustom Pro Laser II & III
    Encounters/Saves August 2011: Radar 3/1, Laser 0/0


  4. #4
    Professional
    Join Date
    Aug 2009
    Posts
    1,147

    Default Re: Ground waves?

    Quote Originally Posted by Reflections View Post
    MEM-TEK had a similar idea of the hood helping to reflect some radiation to the detector, thus increasing alert time.

    I'll second your motion that I believe the ground, terrain in general, will help concentrate a signal help out the detector. For instance, have you noticed that if a LEO is shooting radar into or in a valley you get an alert much sooner then if you're on a flat or over a hill?

    Just an observation, I have no numbers or measurements to follow up.
    I can't say I have. But I have had some awesome long range alerts with hills and corners involved.

  5. #5
    Experienced
    Join Date
    Sep 2008
    Location
    South Jersey
    Posts
    240

    Default Re: Ground waves?

    Have you noticed a difference if vehicles are in front of you, therefore affecting the ground waves. With vehicles in front of you wouldn't you expect better results from a detector mounted as high as possible?
    .

    V1 3.893 - CD - V1C - YaV1 - SAVVY --- REDLINE - ESCORT Live! --- WAZE
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
    Original V1 through 3.893 -- STi MAGNUM - 9500ix -- Original Escort - Passport - SOLO - SOLO2 -- FuzzBuster EliteII

  6. #6
    Professional
    Join Date
    Aug 2009
    Posts
    1,147

    Default Re: Ground waves?

    Quote Originally Posted by randypk View Post
    Have you noticed a difference if vehicles are in front of you, therefore affecting the ground waves. With vehicles in front of you wouldn't you expect better results from a detector mounted as high as possible?
    My car is pretty low, so a high mount is more blocked from traffic than my remote which can see under cars.

  7. #7
    Professional
    Join Date
    Aug 2009
    Posts
    1,147

    Default Re: Ground waves?

    Quote Originally Posted by kpatz View Post

    Another possibility is your STi-R+ happens to be a "hotter" unit than your Redline. They use the same platform, so, in a perfect world, they should have the same amount of sensitivity, but manufacturing variances and component tolerances make some units perform better than others.

    Are you running both in Highway mode? Are you using Ka-band segmentation on the STi-R+?

    I bet in heavier traffic the Redline has better reception since it will have a better "view of the road". Do you find this to be the case?
    Both in Highway mode.
    Traffic or no traffic STi-R+ always wins. I have even held the redline out the window thinking the windscreen could be affecting it.
    I do have RDR off and only two Ka segments on. But for this test I made it fair by only having K band on both detectors.

    Maybe the STi-R is just hotter, $1200 hotter actually so I guess it should.

  8. #8
    Experienced
    Join Date
    Sep 2008
    Location
    South Jersey
    Posts
    240

    Default Re: Ground waves?

    Never thought of it that way. Are there any tests that can show any significant differences between hi/low mounting?

    Always looking for optimum placement!
    .

    V1 3.893 - CD - V1C - YaV1 - SAVVY --- REDLINE - ESCORT Live! --- WAZE
    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
    Original V1 through 3.893 -- STi MAGNUM - 9500ix -- Original Escort - Passport - SOLO - SOLO2 -- FuzzBuster EliteII

  9. #9
    Advanced Member
    Join Date
    Jan 2008
    Location
    Upstate New York where the Stalker Dual is King
    Posts
    1,533

    Default Re: Ground waves?

    Quote Originally Posted by barryswanson View Post
    This is probably a question for someone like Jimbonzz. I have used the search function and came up empty handed.

    I was wondering if microwaves propagate in ground waves also?
    The reason I ask is because I have a sti-r+ mounted about 8 inches off the ground behind a bumper and a redline mounted high in my windscreen and my sti-r always alerts before my redline. Every time.

    I done a little experiment and turned off X and Ka bands on both detectors to make things even and the remote mount always wins on K band or any band for that matter.

    Which brings me back to my ground wave theory. Does it hold any water?
    The ground acts as a cutoff for radar signals and the reflections off the ground would be much weaker than direct line of sight. As another very knowledgeable member once stated.........reflections off the ground (or hood of your car) could actually detract from the sensitivity of your RD. That is because the reflection would be out of phase with the direct signal as they arrive at your antenna which would incurr phase cancellation.........ie. reduced gain by the antenna.

    I believe it's primarily that you have a HOT STi-R! Also, if you had RDR off during your test, that appears to give a decent boost in both reaction time AND sensitivity on the M3. Very similar to Ka Guard off on the V1.

    The higher the mount, the better the reception, it's a fundamental LAW of Radar Detectors. Anything that seems contrary to that rule has us looking for other reasons for the apparent difference in performance.......ie. bad windshield or variance between detectors.

    Of course we'd know for sure if you put that STi-R antenna up on the windshield for a few days and the RedLine behind the bumper!
    [SIGPIC][/SIGPIC]

  10. #10
    Advanced Member
    Join Date
    May 2006
    Location
    Some where in the Bluegrass State
    Posts
    2,115

    Default Re: Ground waves?

    This would be simple refraction of the inital wave itself passing through a time space continum. Radio waves don't always end up propogating in a straight line. They take akward flight paths, and their radiation can reflect, defract, and so forth. The emissions you are getting down low are reflections off of the pavement refracting up into the sesor. Though this would harm over the hill refractions and is not recommended. For Lidar you would be in the right position. However, when it comes to radar you are better to be mounted higher to get a better chance of advanced warning around objects such as rises in the roadway surface etc. Jimbonzz would likely 2nd me on this we have tested devices together before on more than one occasion. He mounts High himself for Radar, Low for lidar for this purpose.

    Alpine-

 

 

Similar Threads

  1. Ground plane ? What is it ?
    By IROCZ in forum Scanners, Ham Radios, & CB's
    Replies: 1
    Last Post: 12-09-2011, 06:14 PM
  2. Man angry at speeders waves BB gun
    By StlouisX50 in forum News Stories
    Replies: 0
    Last Post: 04-29-2011, 07:35 AM
  3. Replies: 2
    Last Post: 01-20-2011, 03:41 PM

Bookmarks

Posting Permissions

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