Why the doubt? Couldn't this just be one input to the Kalman filter? Does the external electronics package require the same temperature regulation as the OCXO? Why not put a cold pack on the DS chip and see if the OXCO output swings as wildly as you expect (I think it would be irresponsibly poor design to control the OXCO outside of the crystal component). Perhaps the early units had microdegree resolution for ambient air, but that doesn't mean the application *requires* microdegree resolution.
Jerry Message: 6 Date: Thu, 5 Feb 2009 18:44:08 +0000 From: Mark Sims <hol...@hotmail.com> Subject: [time-nuts] Tbolt temperature sensor To: <time-nuts@febo.com> Message-ID: <blu125-w41a5b9f9f57936e392bf0ece...@phx.gbl> Content-Type: text/plain; charset="Windows-1252" I doubt the temperature sensor is just used for environmental monitoring. If it was, they would most likely have just used the basic 0.5C resolution reading and have been done with it. Instead, they do the high res read routine and then feed that into a filter to get very smooth high resolution (microdegree scale) values. The whole purpose of a GPSDO with an expensive double oven OCXO is to provide extremely high quality holdover performance when GPS signals go away. To achieve this level of performance one needs to compensate for the affects of temperature on the parts of the system outside the oven. 0.5C resolution is not up to the task of maintaining parts per trillion accuracy. There does not appear to be any other temperature sensor in the Tbolt. ------------ Isn't it likely that a temperature sensor adjacent to the RS232 connector is just going to monitor unit temperature for environmental purposes, perhaps, for example, to give the option for flagging up an overheating situation, in which case surely 0.5C resolution is more than adequate and the "clunkiness" isn't really an issue? _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.