Re: [Discuss-gnuradio] Problems when receiving after transmit

On 1/20/08, Dan Halperin <[EMAIL PROTECTED]> wrote: > In the first set of data, the noise level is what I'd expect and > everything works hunky-dory. After the siggen, however, it all goes > haywire, the noise floor becomes huge even though an adjacent USRP sees > nothing. See >

Re: [Discuss-gnuradio] Problems when receiving after transmit

On 1/21/08, George Nychis <[EMAIL PROTECTED]> wrote: > > This should be a 3.3V logic level. Can you verify you have the right pin? > > I've drawn a red arrow to where I'm measuring from: > http://www.andrew.cmu.edu/user/gnychis/Flex2400.jpg This is the right pin. Are you using a high-impedance p

Re: [Discuss-gnuradio] Problems when receiving after transmit

Johnathan Corgan wrote: On 1/21/08, George Nychis <[EMAIL PROTECTED]> wrote: When running usrp_rx_cfile.py the first time, i get no voltage reading from this pin. Then I run usrp_siggen.py and get a little under 1V at the pin on average. When I stop usrp_siggen.py the pin goes down to about

Re: [Discuss-gnuradio] Problems when receiving after transmit

On 1/21/08, George Nychis <[EMAIL PROTECTED]> wrote: > When running usrp_rx_cfile.py the first time, i get no voltage reading > from this pin. > > Then I run usrp_siggen.py and get a little under 1V at the pin on average. > > When I stop usrp_siggen.py the pin goes down to about 200mV, which is >

Re: [Discuss-gnuradio] Problems when receiving after transmit

Johnathan Corgan wrote: On 1/21/08, George Nychis <[EMAIL PROTECTED]> wrote: I have a logic analyzer and RFX2400 board handy that I can test this out. Which pin is the mixer chip enable pin? U101, pin 8. When running usrp_rx_cfile.py the first time, i get no voltage reading from this p

Re: [Discuss-gnuradio] Problems when receiving after transmit

On 1/21/08, George Nychis <[EMAIL PROTECTED]> wrote: > I have a logic analyzer and RFX2400 board handy that I can test this > out. Which pin is the mixer chip enable pin? U101, pin 8. -- Johnathan Corgan Corgan Enterprises LLC http://corganenterprises.com/ ___

Re: [Discuss-gnuradio] Problems when receiving after transmit

Dan Halperin wrote: You'd have to measure the logic level at the mixer chip enable pin to be sure. I have a logic analyzer and RFX2400 board handy that I can test this out. Which pin is the mixer chip enable pin? - George ___ Discuss-gnuradi

Re: [Discuss-gnuradio] Problems when receiving after transmit

On 1/21/08, Dan Halperin <[EMAIL PROTECTED]> wrote: > Interesting. I don't have a logic analyzer handy but after the holiday I > may find someone who knows how to use one. I can try to replicate it in my lab. > More importantly, do you have suspicions about the solution? ;) The daughterboard co

Re: [Discuss-gnuradio] Problems when receiving after transmit

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Interesting. I don't have a logic analyzer handy but after the holiday I may find someone who knows how to use one. More importantly, do you have suspicions about the solution? ;) As another data point, I've found that performing the second receive at

Re: [Discuss-gnuradio] Problems when receiving after transmit

Dan Halperin wrote: > Just-powered on USRP rev 4.2 with RFX2400 rev 2-6-2006. Current SVN. > > usrp_rx_cfile.py -f 2.485G -d 8 -s pre.dat > usrp_siggen.py -i 16 -f 2.485G > usrp_rx_cfile.py -f 2.485G -d 8 -s post.dat > > In the first set of data, the noise level is what I'd expect and > everythin

Re: [Discuss-gnuradio] Problems when receiving after transmit

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 I should add that I've duplicated this with multiple USRPs of different revisions and different revisions of the RFX 2400 (the 12-26-2006 version as well). So I don't think I broke my hardware... I've also duplicated it at multiple frequencies. - -Dan

[Discuss-gnuradio] Problems when receiving after transmit

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Just-powered on USRP rev 4.2 with RFX2400 rev 2-6-2006. Current SVN. usrp_rx_cfile.py -f 2.485G -d 8 -s pre.dat usrp_siggen.py -i 16 -f 2.485G usrp_rx_cfile.py -f 2.485G -d 8 -s post.dat In the first set of data, the noise level is what I'd expect an