Thread: Radio Location - please help!
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Unread 24-06-2002, 01:03
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#0047 (ChiefDelphi)
  
Join Date: May 2001
Location: Pontiac, MI
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Re: Radio Location - please help!
Posted by Al Skierkiewicz at 2/19/2001 1:34 PM EST


Engineer on team #111, Wildstang, from Wheeling High & Rolling Meadows High and Motorola.


In Reply to: Radio Location - please help!
Posted by Janna on 2/18/2001 4:19 PM EST:



If you hold the modem outside of the robot, do you still have a problem? If not than you are either shielding the energy or pulling the antenna off frequency. It seems like this a problem teams run into every year. The rubber flexible antenna on the end of the radio modem at the robot side, is sensitive to metal objects being placed near it. Worst case is for the very end to be touching a metal object. Steel is worse than aluminum. What takes place is that the object pulls the resonant frequency of the antenna to a much lower frequency. The antenna becomes very inefficient and the modem stops handshaking. Watch the lights on the side of the modem and experiment with moving it around.
Many teams try to bury the modem inside the robot and then surround it with metal covers and structural steel. All of those things reduce the efficiency.
Please note that the antenna is closer to one side of the modem than the other. When mounting the modem, take advantage of this and mount the antenna as far away from a metal object as you can. For a few years now, we have tiewrapped the modem directly to a 1" aluminum box tube and had no problems.
If all else fails, and you suspect that the modem has been abused, then the rubber antenna may be broke. It is flexible, but not indestructable.
al



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