time-nuts@lists.febo.com

Discussion of precise time and frequency measurement

View all threads

Re: [time-nuts] precision frequency/time/amplitude reference

DW
David Witten
Mon, Oct 9, 2017 4:58 PM

Jim,

If I understand what you are attempting (I may well not), you might
consider the approach taken here:

https://github.com/tejeez/rtl_coherent

and here:

https://github.com/tejeez/rtl_coherent/blob/master/hardware/simple/README.md

or order a noise-source and antenna switches from here:

http://coherent-receiver.com/products/rtl-sdr-extension-card/noise-source

http://coherent-receiver.com/products/rtl-sdr-extension-card/antenna-switch

(disclaimer: no personal connection to above links)

Dave

Jim, If I understand what you are attempting (I may well not), you might consider the approach taken here: https://github.com/tejeez/rtl_coherent and here: https://github.com/tejeez/rtl_coherent/blob/master/hardware/simple/README.md or order a noise-source and antenna switches from here: http://coherent-receiver.com/products/rtl-sdr-extension-card/noise-source http://coherent-receiver.com/products/rtl-sdr-extension-card/antenna-switch (disclaimer: no personal connection to above links) Dave
J
jimlux
Mon, Oct 9, 2017 11:51 PM

On 10/9/17 9:58 AM, David Witten wrote:

Jim,

If I understand what you are attempting (I may well not), you might
consider the approach taken here:

https://github.com/tejeez/rtl_coherent

that is where you have a common clock distributed to the RTLs
"A single 28.8 MHz reference clock is distributed to all dongles. "

What I want to do is have the dongles completely independent running
with their own computer off a battery.  Capture the data to a SDcard
and then post process it to do the interferometry

And do this with a self contained calibration approach (i.e. not depend
on there being a convenient radio station which has a signal in band, etc.)

On 10/9/17 9:58 AM, David Witten wrote: > Jim, > > If I understand what you are attempting (I may well not), you might > consider the approach taken here: > > https://github.com/tejeez/rtl_coherent that is where you have a common clock distributed to the RTLs "A single 28.8 MHz reference clock is distributed to all dongles. " What I want to do is have the dongles completely independent running with their own computer off a battery. Capture the data to a SDcard and then post process it to do the interferometry And do this with a self contained calibration approach (i.e. not depend on there being a convenient radio station which has a signal in band, etc.)