Dummy load / direct wire connection concept

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Nordin bouchtaoui at gmail.com
Mon Jul 27 07:23:12 UTC 2009


Damn, your lab has serious equipment man!
Wow! I mean, cool! :)


dexter schreef:
> Hi folks,
>
> In order that a rogue GSM-BTS can cause a lot of trouble with the 
> regulation offices there is a need for a dummyload solution.
>
> I have 2 ideas in mind:
>
> The first one uses attenuators to set up a direct wired connection:
> http://root.runningserver.com/pub/desktop-gsm1.png
>
> The second one uses parasitic coupeling in a shilded box:
> http://root.runningserver.com/pub/desktop-gsm2.png
>
> The second solution in my opinion the most save one because the BTS 
> does not send directly in its own receiver as well as the MS do not 
> send directly into the BTS. But i also think that this solution is too 
> crappy, i think there must be a more accurate way.
>
> The first solution fullfilly my demands in accurateness. The impedance 
> is 50 Ohms and attenuators ensure that the signal that is transmitted 
> between two points are attenuated enough - in theory...
>
> I have no experience in those things, i never connected a sender and a 
> receiver directly for measurement proposes. I am afraid to damage BTS 
> and/or MS by trying the first solution.
>
> What do you think, what would you do? How do you ensure that you do 
> not interfere with the with the official GSM networks? I think 
> sometimes it would be very nice to make 100% sure that no HF signals 
> leave the desktop.
>
> PS: One of my inspirations: http://www.comlab.hut.fi/Resources/GSM.html
>
> regards.
> Philipp
>
>
>
>





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