Hello Mike, attached is a 10MHz DIP-14 TCXO Phase Noise plot from a random LTE-Lite unit. I had sent out a 20MHz typical phase noise plot some weeks ago, and comparing the two they are almost perfectly 6dB apart as would be expected from the 20log(n/m) relationship. There are variations from unit to unit of course, but it does not seem like one version of the board or the other has advantages in terms of phase noise. I had also sent out a superimposed plot of the 20MHz and the divide-by-2 10MHz output of the same board at that time, and again the relationship was almost perfectly 6dB lower at 10MHz versus 20MHz. While phase noise follows theory, it does seem that the DIP14 metal shield has a beneficial effect on the ADEV stability though. The plots we are getting are pretty darn good, and I want to test more boards before I post any ADEV, because its quite a bit better than our specification and I want to make sure its real. The 10MHz DIP-14 boards do not have an isolating buffer like the 20MHz boards do, on these the TCXO drives the output directly, so one must be careful to set the equipment to 1M Ohms input impedance or use a buffer externally, which is what we did to measure the attached PN plot. Bye, Said In a message dated 11/20/2014 13:48:22 Pacific Standard Time, [email protected] writes:
Hi Said, Have you ever done a phase noise comparison of the 20 MHz TCXO divided by 2 and the 10 MHz TCXO version? My unit has only been powered for a few hours for initial tests. I'm using the uBlox U-Center software version 8.12 for monitoring the GPS. Mike On 11/20/2014 3:32 PM, S. Jackson via time-nuts wrote: > Hello everyone, > > after what must have been the longest thread in T-nuts history its almost > all quiet today. I am going to take advantage of that and announce some > good news: > > Its a miracle: the 10MHz DIP-14 TCXOs for the LTE-Lite came in weeks ahead > of schedule from the factory! And they work very well. > > We will thus be shipping out the 10MHz LTE-Lite eval boards in the next > couple of working days. There are still a number left for sale on Ebay > (search for "LTE Lite GPSDO"), so if you were hesitant to get one due to the long > lead-time, then now is your chance. > > Also, after being in time nuts hands for almost a week I am surprised > there are very few mails, questions, or comments about the 20MHz boards, and we > have received almost no feedback on Ebay :( I hope that is a good sign. > > Bye, > Said > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- 73, Mike, N1JEZ "A closed mouth gathers no feet"
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