[time-nuts] ADCs for phase noise measurement

2016-06-13 Thread Dan Kemppainen
The 2378-20 is a pretty nice ADC. I expect the 2368-24 to be good also. It should be easy to see at least -130dBfs noise floor with an FFT. Keep in mind supply rail noise, and REF voltage noise etc. That's a lot of resolution and bandwidth in one unit! The DC890B board appears to run an FTDI F

Re: [time-nuts] ADCs for phase noise measurement

2016-06-11 Thread Bob Camp
Hi I think you will find that you need the DC890 add on board to run Pscope. Bob > On Jun 11, 2016, at 4:08 PM, Richard (Rick) Karlquist > wrote: > > > > On 6/11/2016 6:33 AM, Attila Kinali wrote: >> Hoi Rick, >> >> use a small uC board to interface with the PC. Saving the samples in >> a

Re: [time-nuts] ADCs for phase noise measurement

2016-06-11 Thread Attila Kinali
On Sat, 11 Jun 2016 11:53:22 -0700 "Richard (Rick) Karlquist" wrote: > Good call on the LTC2368-24. The eval board for it has considerably > better support (like p-scope) than do the Analog Devices eval boards. > I think this might work for me. What are the tradeoffs between SAR > and sigma-del

Re: [time-nuts] ADCs for phase noise measurement

2016-06-11 Thread Richard (Rick) Karlquist
On 6/11/2016 6:33 AM, Attila Kinali wrote: Hoi Rick, use a small uC board to interface with the PC. Saving the samples in a wav file and using one of the many FFT tools shouldn't be a problem. This gets even better. The free Pscope software comes with FFT. I don't even need to fool with e

Re: [time-nuts] ADCs for phase noise measurement

2016-06-11 Thread Richard (Rick) Karlquist
On 6/11/2016 6:33 AM, Attila Kinali wrote: Hoi Rick, I don't know which phase noise measurement sturcture you are going to use exactly or what your goals are, so I am guessing here a little bit... I'm interested in at least 10-100 Hz offset, 1-1000 Hz offset would be a bonus. Thus audio is

Re: [time-nuts] ADCs for phase noise measurement (was: windows for FFT measurements of phase noise)

2016-06-11 Thread Bob Camp
Hi If you really want to go low noise at the low end, various outfits (TI is one) make ADC’s aimed at geo phone applications. Some do cute things like chopper inputs. Others approach it without the chopper. Cost is often a bit high. Finding them on a card can be tough. There are a number of au

[time-nuts] ADCs for phase noise measurement (was: windows for FFT measurements of phase noise)

2016-06-11 Thread Attila Kinali
Hoi Rick, I don't know which phase noise measurement sturcture you are going to use exactly or what your goals are, so I am guessing here a little bit... On Fri, 10 Jun 2016 17:15:22 -0700 "Richard (Rick) Karlquist" wrote: > I am now putting together a modern homebrew phase noise system. > I a