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Per Westermark
01/22/12 11:19
Read: 350 times
Sweden


 
#185625 - No - side band disturbances will still be uV and illegal
Responding to: Jecksons Ben's previous message
Jecksons Ben said:
How do you know if a circuit produces disturbance on other frequencies if you can't scan these frequencies with a suitably narrow-banded receiver? A normal oscilloscope will not get you far - it can't do FFT on radio-frequency signals to show overtone spectrum. And even really high-end GHz-capable multi-GS digital scopes who can sample the radio spectra would normally not have the sensitivity for picking up uV signals.


so that's why 500mW to 1 Watt.

Thank you
Jeckson S Ben

You are totally missing something.

With a transmitter emitting 1 W, your RF analyzer will not pick up 1V of signal strength. And the intresting thing isn't what it sees exactly at the center of your transmitting frequency. It's what it sees to the sides. And what overtones it sees. Don't you realize that uV signals are strong enough to disturb if they are leak transmissions at the wrong frequency?

Sorry but no. Very much no. Even modules of that power are not safe. Even modules requires you to test your equipment in a shielded room, to make sure that you do not leak RF energy through supply voltage or data signal lines.

The equipment I work with do use modules of this power or higher. And we have spent significant amount of time measuring and optimizing the layouts just to make sure the device fulfills all regulations.

List of 19 messages in thread
TopicAuthorDate
RF amplifier for 4XX Mhz      JecksonS Ben      01/17/12 03:47      
   Probably illegal?      Andy Neil      01/17/12 12:46      
      maybe...      JecksonS Ben      01/18/12 06:12      
         Look for a legal solution!      Kai Klaas      01/18/12 11:14      
            It's immune with Jam      JecksonS Ben      01/19/12 01:46      
               Immune?      Per Westermark      01/19/12 02:55      
                  very high      JecksonS Ben      01/19/12 23:31      
                     Don't need kW to jam civilan "toy" equipment      Per Westermark      01/20/12 03:06      
                        You don't need to look at huge transmitters.?      JecksonS Ben      01/21/12 08:25      
                           Are there stores of info how's to implemented that?      Andy Neil      01/21/12 09:29      
                              Instruments        Per Westermark      01/21/12 09:42      
                                 that's why..      JecksonS Ben      01/22/12 07:51      
                                    No - side band disturbances will still be uV and illegal      Per Westermark      01/22/12 11:19      
                                       missing      JecksonS Ben      01/23/12 07:27      
                              true      JecksonS Ben      01/22/12 07:49      
                                 No! No!! No!!!      Andy Neil      01/22/12 10:03      
                                    ??      JecksonS Ben      01/23/12 07:37      
   Teh limit is..      Jez Smith      01/17/12 13:57      
   500mW ...      Rob Klein      01/17/12 15:24      

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