I think the user FE5680 manual says you can change the tuning word as much as you like. But changing the EEPROM is different, that is used on power up. In a GPSDO you would likely want to send a command over the serial interface when you need to make a change but you would only write to the EEPROM as a special case, maybe if you wanted to place the Rb in a none GPS mode so it could be portable. I think you would store the power-on defaults inside the GPSDO controller's uP. Anyways changing the running word and writing it to memory are different.
BTW I made a temperature controller for mine. The unit is bolted to a large heat sink and placed in a box with a fan. The fan speed is controlled by the heat sink temperature. So it is an ovenized box that is powered by waste heat. My problem is finding a decent temperer sensor. I've tried several and they are noisy. This version is simple. The parts list is just three tab voltage regulators, a power darlinton (for the fan motor) and an 8-pin AVR chip. The AVR uses one analog input to sense temperer and one analog output to control the fan speed. The software is very simple. Once I find a good temperature sensors I want to also measure the ambient air temperature and control the fan based on the delta between the heat sink and ambient. On Fri, Jun 20, 2014 at 5:11 PM, Mark Sims <hol...@hotmail.com> wrote: > Maybe... maybe not. Some of the Rb's store the tuning word in the > processor EEPROM and those have a rather limited number of write cycles. > > ---------------- > You can change the DDS tuning words almost as many times per minute or per > second as you wish to achieve the desired average accuracy. > _______________________________________________ > 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. > -- Chris Albertson Redondo Beach, California _______________________________________________ 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.