-30 dBm sounds correct for a gain of 45 if you are using a B200 family
USRP. They have a maximum tx power of about +10 dBm at a gain of 89.
Run uhd_usrp_probe to see the full available gain information for your USRP.
On 3/16/2021 5:11 PM, AKINYELE ITAMAKINDE wrote:
connected the antenna to the good channel Rx/TxThanks, I have been
checking out your suggestions.
What i meant by "negative Tx power" is that the Tx power is giving
negative value (-30dbm)
1. I have upgraded to GNURadio >=3.8 but it is giving this warning
message after trying to import QT GUI sink
Block paths:
/home/elect/gnuradio/share/gnuradio/grc/blocks
Warning: restarting the docstring loader (crashed while loading
'qtgui_bercurve_sink')
Warning: restarting the docstring loader (crashed while loading
'qtgui_const_sink_x')
Warning: restarting the docstring loader (crashed while loading
'qtgui_edit_box_msg')
Warning: restarting the docstring loader (crashed while loading
'qtgui_freq_sink_x')
Warning: restarting the docstring loader (crashed while loading
'qtgui_histogram_sink_x')
Warning: docstring loader crashed too often
Pls, can you help to solve this problem?
2. For QT GUI Sink bandwidth, I will do that when the above problem is
solved.
3. Yes I measured the signal power using a spectrum analyzer.
4. Did you check your signal amplitude at USRP bloc input? i don't
know how to do this but check it when i solve the problem
5. yes, i connected the antenna to the good channel Rx/Tx.
On Fri, Mar 12, 2021 at 3:30 PM Christophe Seguinot
<christophe.segui...@orange.fr <mailto:christophe.segui...@orange.fr>>
wrote:
Hi
- What does "negative Tx power" means ?
A few suggestions:
* move to GNURadio >=3.8 (most of us uses GR 3.8 or 3.9 so it's
difficult to help for outdated GR 3.7)
* QT GUI Sink : Bandwith should be equal to sample rate of the
block incoming signal, i.e. samp_rate at the RRC Filter output
(the FFT Sink does not work as a real spectrum analyzer)
* Did you measure the signal power using a spectrum analyzer ?
When do so, the receiving antennna being close to the emitter
antenna, you should get the -20 to -30 dB as compared to the
emitted power (frequency close to 1GHz and 6dBi antennas
(Indoor panel), this is depending on frequency and antenna
gain). If your emitted power is +20 dBm, you should measure
something in the range 0 dBm to -20 dBm. If not, there is
something wrong in the transmission chain.
* Did you check your signal amplitude at USRP bloc input (The
maximum value should be 1 Volt to get maximum RF power which
also depend on USRP settings
* Did you connected the antenna to the good channel Rx/Tx ?
Sincerely, Christophe
On 12/03/2021 15:08, AKINYELE ITAMAKINDE wrote:
Good day to all community members.
Please, I need you to help correct this flow graph configuration.
The Tx power radiating is too minimal. I have adjusted and also
added some other blocks to boost the signal but all to no avail.
The flow graph is been used for propagation channel measurement.
I will like someone to take me through or send video and other
link on how to solve this problem. The flow graph is attached.
Thank you.
Akinyele.
