You have not read or internalized the specifications for the oscillator
on the USRP which is intimately involved in this system. It is 50 ppm
accuracy which is bad enough, but look at the can. It is begging to
have thermal variances. Start up the usrp and your process and
investigate
Peter Monta wrote:
Martin Dvh wrote:
Maybe you could inject a stable frequency near the wanted RX frequency.
Say a few Mhz away from the 1.57542e9 you want to receive.
Then you could use this in the output to remove the jitter and LO drift.
for example:
inject 16 Mhz (=25 harmonic
There is a multiplier circuit/ PLL in the DBS-RX. Whatever phase noise
is coming from the oscillator is being multiplied considerably by this
upconversion to be used at LO in the DBS-RX. You cannot get low phase
noise oscillators and high performance mixers in that small a package.
Together
Robert McGwier wrote:
There is a multiplier circuit/ PLL in the DBS-RX. Whatever phase
noise is coming from the oscillator is being multiplied considerably
by this upconversion to be used at LO in the DBS-RX. You cannot get
low phase noise oscillators and high performance mixers in that
I've noticed that the DLL of my software receiver settles to +15 Hz,
and the true IF is +24 kHz from the predicted IF. This would indicate
that the 64 MHz board clock is ~1 kHz from its spec value. This, in
itself is not a problem, but I was wondering if this was within
tolerances of the
Brian:
From what I see it does not continuously stream data, which is a
requirement for my needs. Additionally I am looking at recording GPS L2C
and the new Galileo frequencies, so a tuneable front end is a must.
Greg
Brian Padalino wrote:
On 3/6/07, Gregory W Heckler [EMAIL PROTECTED]
On Tue, Mar 06, 2007 at 04:57:55PM -0500, Gregory W Heckler wrote:
Brian:
From what I see it does not continuously stream data, which is a
requirement for my needs. Additionally I am looking at recording GPS L2C
and the new Galileo frequencies, so a tuneable front end is a must.
I'm
Martin Dvh wrote:
Maybe you could inject a stable frequency near the wanted RX frequency.
Say a few Mhz away from the 1.57542e9 you want to receive.
Then you could use this in the output to remove the jitter and LO drift.
for example:
inject 16 Mhz (=25 harmonic of 64MHz) at the
