Ivan Kluchnikov <Ivan.Kluchnikov <at> fairwaves.ru> writes:

> 
> 
> Hi Yavuz,
> Try to use achemeris/umtrx-fixes branch for osmo-trx.
>  Also check that you use the latest version of UHD from 
https://github.com/fairwaves/UHD-Fairwave
> If you have old version of FPGA and ZPU, flash current FPGA and ZPU 
images: http://umtrx.org/hardware/flashing/
> 18 сент. 2014 г. 21:49 пользователь "Arif" <arif.i84 <at> gmail.com> 
написал:Yavuz Mert <yavuzmertt <at> gmail.com> writes:
> >
> > Hi,
> > I have a problem setting tx power in osmo-trx. I debugged and found
> that
> > correct gain value is passed to uhd_device::setTxGain. But whatever
> value is
> > set to usrp_dev->set_tx_gain, usrp_dev->get_tx_gain(chan) returns 
-28
> db.
> > In uhd_device::setTxGain(double db, size_t chan) I put  a printf to
> see
> > values.
> >
> >       usrp_dev->set_tx_gain(db, chan);
> >       tx_gains[chan] = usrp_dev->get_tx_gain(chan);
> >       printf("Written %f, read %f\n",
> db,tx_gains[chan]);fflush(stdout);
> >
> > Written 21.000000, read -28.000000
> > Written 11.000000, read -28.000000
> > Written -35.000000, read -28.000000
> >
> > But despite the read values, actually the power is somewhat changed. 
I
> plugged
> > TX1 to spectrum analyzer and set TX gain from -35 to 21 in 2 db 
steps.
> Until
> > -5 db the signal gradually increases, but from -5db to -3db it drops
> down to
> > lowest. Is there something I should pay attention while using higher
> gain
> > values. Meanwhile I do not play with RX gain or noise level, leave
> them at
> > default values.
> >
> > thanks
> > yavuz
> >
> >
> Hi,
> i am facing the same issue, and have spend the whole day to find that
> tx_gain value is not set no matter what. the output signal only
> registers maximum of 1.6 dBm on watt-meter.
> Temperature is not high so i doubt temperature is a problem. may be 
its
> related to uhd driver? or tx_gain values not written to eeprom.
> i might be missing some configuration option or trick. any help is 
much
> appreciated,
> thanks,
> arif
> 
> 
> 

Hello Ivan,

thank you replying cause i'm having same problem. i flashed current 
version of ZPU and FPGA images. 

then again i ran the test using following command 

tx_samples_from_file --rate 1083333 --freq 9550e5 --bw 1500000 --file 
multiframe_norm.dat --type float --loop--gain 18 --subdev A:0

but still i see the same actual tx gain: -28.0000 dB.. 

i couldn't find the achemeris/umtrx-fixes branch for osmo-trx. Further i 
have cloned the latest code from uhd-fairwaves as well. 

thanks,
arif



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