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Re: [Discuss-gnuradio] Setting tx_gain > 20 dB => no effect? (USRP2, XC
Marcus D. Leech
Re: [Discuss-gnuradio] Setting tx_gain > 20 dB => no effect? (USRP2, XCVR2450)
Wed, 23 Jun 2010 07:42:17 -0400
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> Hi Jeffrey,
> thanks for the advice. The standard power of USRP2 should be enough
> for me, if I really get it :)
> In the specifications for XCVR2450 it says 100mW or 20 dBm.
> The jamming is already working, but a bit more power would be fine ;)
> Yesterday I moved the micaz node around my USRP2 to find the maximum.
> I couldn't get more than -13 dBm even with my micaz nearly touching
> the antenna of the USRP2.
> I used 30 dB gain at sink (just to be safe) and an amplitude of 1
> again (so 21+ dB gain would have been about equal then).
> Is there something I could do softwarewise to get more than about -13
> dBm? (another amplitude, samp_rate, interpolation ...) Doing something
> wrong hardware or softwarewise? Perhabs the micaz RSSI value isn't
> exact enough?
> I don't expect exactly 20 dBm at the micaz, but it should be more than
> -13 dBm with the micaz just about 1cm distance to antenna, shouldn't
> Sven Oliver
> Discuss-gnuradio mailing list
For an isotopic radiator received power is proportional to the inverse
cube of the distance.
Plus your receive antenna won't be 100% efficient, etc. For ordinary
radios a received signal
of -13dBm is *thundering* strong.
Shirleys Bay Radio Astronomy Consortium