Re: [Discuss-gnuradio] Connecting two USRP B200 radios
Hi Ash, Yes, you need to use an attenuator if you are connecting the B200's directly together with a cable. I would recommend at least 30dB of attenuation, but that depends on your settings. It is recommended that you do not input more that -15 dBm into the receiver of the B200, as this can damage the device. With that said, what settings are you using? I see you have 8dB gain for transmit (you may need to increase this), what about receive on the other B200? Which port are you using to receive on the B200 (TX/RX or RX2)? -Trip On Fri, Nov 6, 2015 at 10:46 AM, Ashish Pasha Sheikh wrote: > Hello everyone, > > i am new to the world of SDR. I currently have two USRP B200 radios. I > would like to connect the Tx port of one SDR to Rx port of second SDR using > a cable to visualize the transmitted bits. > > I am generating random bits with Ts=1/1 and 50 samples per frame. > Using a rectangular pulse shaping with 20 pulse length it would output > me a samples with data rate of 200KHz. I am transmitting the baseband > signal with gain of 8 and interpoaltion factor 512 over a 432e6 frequency. > > > now i want to visualize the signal by receiving it on another B200 radio . > I receive complete noise irrespective of whether i am transmitting (or) > not. So can i connect the two B200 radios using a cable so as to see the > clean recevieed spectrum.. > > In this case I believe i should use a attenuator in between the cables.Can > you please point more on this ? can i drectly connect without an > attenuator?? > > > Ash > undergrad student, > > > ___ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Connecting two USRP B200 radios
On 11/06/2015 10:46 AM, Ashish Pasha Sheikh wrote: Hello everyone, i am new to the world of SDR. I currently have two USRP B200 radios. I would like to connect the Tx port of one SDR to Rx port of second SDR using a cable to visualize the transmitted bits. I am generating random bits with Ts=1/1 and 50 samples per frame. Using a rectangular pulse shaping with 20 pulse length it would output me a samples with data rate of 200KHz. I am transmitting the baseband signal with gain of 8 and interpoaltion factor 512 over a 432e6 frequency. now i want to visualize the signal by receiving it on another B200 radio . I receive complete noise irrespective of whether i am transmitting (or) not. So can i connect the two B200 radios using a cable so as to see the clean recevieed spectrum.. In this case I believe i should use a attenuator in between the cables.Can you please point more on this ? can i drectly connect without an attenuator?? Ash undergrad student, Always use an attenuator, of at least 30dB. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Connecting two USRP B200 radios
For RX gain, you will probably need around 20-40dB. Yes, you should place the 30dB attenuator in line with your connection. You should be able to slowly increase the transmit gain until you see the signal. Double check that the correct ports on each board on in use, a green light will light up when the corresponding port is activated. Again, all these settings are application specific, so it may take some experimentation to get the correct settings for your case. -Trip On Fri, Nov 6, 2015 at 12:40 PM, Ashish Pasha Sheikh wrote: > > For transmission , I am using Tx/Rx port on first B200 radio ... > > For receiver part , I am using Rx port .. I was using MATLAB as a > platform . Do you mean that i should use atleast gain of 15 and place an > attenuator of 30 dB and connect to Receiver (rx port) ... how much Rx gain > i should keep in my settings?? > > ash > > On Fri, Nov 6, 2015 at 10:57 AM, James Humphries < > james.humphr...@ettus.com> wrote: > >> Hi Ash, >> >> Yes, you need to use an attenuator if you are connecting the B200's >> directly together with a cable. I would recommend at least 30dB of >> attenuation, but that depends on your settings. It is recommended that you >> do not input more that -15 dBm into the receiver of the B200, as this can >> damage the device. >> >> With that said, what settings are you using? I see you have 8dB gain for >> transmit (you may need to increase this), what about receive on the other >> B200? Which port are you using to receive on the B200 (TX/RX or RX2)? >> >> -Trip >> >> On Fri, Nov 6, 2015 at 10:46 AM, Ashish Pasha Sheikh >> wrote: >> >>> Hello everyone, >>> >>> i am new to the world of SDR. I currently have two USRP B200 radios. I >>> would like to connect the Tx port of one SDR to Rx port of second SDR using >>> a cable to visualize the transmitted bits. >>> >>> I am generating random bits with Ts=1/1 and 50 samples per frame. >>> Using a rectangular pulse shaping with 20 pulse length it would output >>> me a samples with data rate of 200KHz. I am transmitting the baseband >>> signal with gain of 8 and interpoaltion factor 512 over a 432e6 frequency. >>> >>> >>> now i want to visualize the signal by receiving it on another B200 radio >>> . I receive complete noise irrespective of whether i am transmitting (or) >>> not. So can i connect the two B200 radios using a cable so as to see the >>> clean recevieed spectrum.. >>> >>> In this case I believe i should use a attenuator in between the >>> cables.Can you please point more on this ? can i drectly connect without an >>> attenuator?? >>> >>> >>> Ash >>> undergrad student, >>> >>> >>> ___ >>> Discuss-gnuradio mailing list >>> Discuss-gnuradio@gnu.org >>> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio >>> >>> >> > ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
