Re: [Discuss-gnuradio] grGPS Preliminary Schematic

David Bengtson wrote: Then you should be able to get GPS from a DBS board using an external LNA/Antenna combination. The software is left as an exercise for the student :-). Remind me, and I'll show a spectral spike of the GPS L1 signal. I have a DBS_RX, with an external LNA right at the fe

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Matt Ettus wrote: You may well be able to do it with the DBS board. However, GPS is a pretty weak signal, and I suspect that the noise figure is too high. The DBS board has about a 3-5 dB noise figure as I recall, but that doesn't really matter. Nearly all GPS antennas have their own LNAs ins

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

> You may well be able to do it with the DBS board. However, GPS is a > pretty weak signal, and I suspect that the noise figure is too high. The DBS board has about a 3-5 dB noise figure as I recall, but that doesn't really matter. Nearly all GPS antennas have their own LNAs inside, so noise fi

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Martin Dvh wrote: David Bengtson wrote: After far to long, I've updated the information on the Gnu Radio GPS board. I've finished a preliminary schematic, and I'd appreciate any comments that anyone might have. Why don't you use the usrp to generate your 16.384 or 32.768 MHz refclock. Most daug

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

TED], gnuradio mailing list Subject: Re: [Discuss-gnuradio] grGPS Preliminary Schematic Date: Thu, 06 Apr 2006 06:18:49 -0400 Martin Dvh wrote: David Bengtson wrote: After far to long, I've updated the information on the Gnu Radio GPS board. I've finished a preliminary schematic,

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Martin Dvh wrote: David Bengtson wrote: On 4/6/06, *Robert W McGwier* <[EMAIL PROTECTED] > wrote: David Bengtson wrote: > Martin Dvh wrote: >> Why don't you use the usrp to generate your 16.384 or 32.768 MHz >> refclock. >> Most daugterboard

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Robert W McGwier wrote: David Bengtson wrote: Martin Dvh wrote: Why don't you use the usrp to generate your 16.384 or 32.768 MHz refclock. Most daugterboards (except the tvrx) use this feature (They all use a 4Mhz refclock on io pin 0. The only difference with your design is that you need anot

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

On Thu, Apr 06, 2006 at 06:55:57PM +0200, Martin Dvh wrote: > > (Life would be so much easier if all the clocks on the usrp would first go > through the fpga. > Which could then upconvert/divide/pll/override/combine any clock in verilog > software.) Rule 1 for digitizing RF: never let the clock

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

On Thu, Apr 06, 2006 at 06:55:57PM +0200, Martin Dvh wrote: > (Life would be so much easier if all the clocks on the usrp would first go > through the fpga. > Which could then upconvert/divide/pll/override/combine any clock in verilog > software.) > > Greetings, > Martin The phase noise would b

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

David Bengtson wrote: On 4/6/06, *Robert W McGwier* <[EMAIL PROTECTED] > wrote: David Bengtson wrote: > Martin Dvh wrote: >> Why don't you use the usrp to generate your 16.384 or 32.768 MHz >> refclock. >> Most daugterboards (except the tvrx)

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

David Bengtson wrote: Martin Dvh wrote: Why don't you use the usrp to generate your 16.384 or 32.768 MHz refclock. Most daugterboards (except the tvrx) use this feature (They all use a 4Mhz refclock on io pin 0. The only difference with your design is that you need another frequency. The cyclo

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Daniel O'Connor wrote: According to the datasheet the PLL can only do m/n where m is between 1 and 32 and n is between 1 and 4. Therefore I don't see how it's possible. I was only guessing before, but I just checked the datasheet and it seems impossible. You could get close with a Stratix

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

mailing list Subject: Re: [Discuss-gnuradio] grGPS Preliminary Schematic Date: Thu, 06 Apr 2006 06:18:49 -0400 Martin Dvh wrote: David Bengtson wrote: After far to long, I've updated the information on the Gnu Radio GPS board. I've finished a preliminary schematic, and I'd appreciate

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Martin Dvh wrote: David Bengtson wrote: After far to long, I've updated the information on the Gnu Radio GPS board. I've finished a preliminary schematic, and I'd appreciate any comments that anyone might have. Why don't you use the usrp to generate your 16.384 or 32.768 MHz refclock. Most daug

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

On Thursday 06 April 2006 15:11, Marcus Leech wrote: > > Also, I think getting 32.768 MHz from 4Mhz with a PLL would be pretty > > difficult (if not impossible) > > Given that you haven't looked into the PLLs on the FPGA, it's rather too > early > to conclude that you couldn't synthesize 32.768Mh

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Farnell sell 32.768 MHz crystals (They're not what you'd call cheap though - AU$17). Hmm they have 16.384 MHz ones for $12.81. Still not cheap.. Also, I think getting 32.768 MHz from 4Mhz with a PLL would be pretty difficult (if not impossible) Given that you haven't looked into the PLLs

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

On Thursday 06 April 2006 13:14, Martin Dvh wrote: > Why don't you use the usrp to generate your 16.384 or 32.768 MHz refclock. > Most daugterboards (except the tvrx) use this feature (They all use a 4Mhz > refclock on io pin 0. The only difference with your design is that you need > another freque

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

David Bengtson wrote: > After far to long, I've updated the information on the Gnu Radio GPS > board. I've finished a preliminary schematic, and I'd appreciate any > comments that anyone might have. Why don't you use the usrp to generate your 16.384 or 32.768 MHz refclock. Most daugterboards (excep

Re: [Discuss-gnuradio] grGPS Preliminary Schematic

Is there an inherent problem with using the DBS Rx? I think this discussion started once, but I can't find it in the archives. Has any one successfully captured GPS and processed out position information using GNU Radio and USRP? I remember Krys Kamieniecki was working on it, but last I remem

[Discuss-gnuradio] grGPS Preliminary Schematic

After far to long, I've updated the information on the Gnu Radio GPS board. I've finished a preliminary schematic, and I'd appreciate any comments that anyone might have. Page: http://www.keystoneradio.com/grGPS.html Schematic http://www.keystoneradio.com/pdfs/Schematic_1.pdf Thanks Dave