Re: [Discuss-gnuradio] Setting tx_gain > 20 dB => no effect? (USRP2, XCVR2450)

[Sven Oliver Kreis]

Hi,

ok, you two convinced me :) I am not that experienced yet. It just 
seemed a bit low to me. If it is a value one can expect, I will continue 
to tune the jamming signal.
The results aren't bad yet. But it is always good to improve efficiency :)

Have a nice day
Sven Oliver



Am 24.06.2010 15:56, schrieb Jeffrey Lambert:
> On 6/24/2010 5:11 AM, Sven Oliver Kreis wrote:
> > Hi Marcus,
> ...
>
> > But -13 to 20 is a bit much, isn't it?
>
> It's not much at all, in fact, expect a lot more.  Look at it only in 
> terms of dB, beccause the fact is, whenever you have a communications 
> system, you can only couple so much energy to the receiver.
>
> > I don't think the micaz is very unprecise. Perhaps a few dBm.
>
> A few dBm is horrible precision.
>
> Perhaps
> > it is -8 instead of -13. And perhaps I just get 10 or 15 dBm out of
> > the URSP2 antenna.
>
> You will always have some loss.  The maximum output power from the 
> AD9862 IC is a maximum value.
>
> > Even than there is still a huge factor difference.
>
> That's not huge.
>
> > So if I didn't calculate something wrong or have wrong assumptions ...
> > there should be a way to improve it. At least a bit. :)
>
> The only way you're going to improve this is by using a more efficient 
> antenna or an antenna with gain, or by putting an amplifier on the 
> USRP output.  Perhaps it is also likely there is some improvement 
> needed with the jamming signal you are using.