Re: [time-nuts] How to properly characterize 32kHz oscillators manually and with a microcontroller?

Pete, Instead of doing this in an ISR, feed the 32KHz into one of the timer/counter inputs, and clock the timer off of that (probably TIMER2), then just have an ISR for the overflow vector. So, when your X bit timer overflows, you can just add that to your total, when you reach your 1000s (or

[time-nuts] Home-brew GPSDO

Hello All, Thanks to the advice earlier, I’ve gotten my HP 10544A OCXO working well, and close enough in frequency that the EFC is useful. I’ve started work on putting together a home-brew GPSDO. In short, it’s an Arduino Due, and a u-blox MAX-7 module. (I may think about grabbing a LEA module

Re: [time-nuts] HP 10544A Repair

Howdy All, This thread has split into a couple, but I’ll try to respond here to the various things. Based on how this crystal warms up, it does appear that it is a BT type crystal, as it warms up frequency goes up, and as it gets hotter eventually turns around and heads downhill again. I’ve

Re: [time-nuts] HP 10544A Repair

Hal, It depends a lot on the thermistor. As with any component, there are higher precision models that would be pretty repeatable within a model number, and cheaper ones that will be somewhat less repeatable. In this case I didn’t have a specific model number, nor specific nominal/beta values,

Re: [time-nuts] HP 10544A Repair

Mark, I don’t see that referenced in the documentation, and the frequency adjustment pot appears to be plastic, but I will compare a non-conductive tool, to a conductive one to see if it makes a difference. Nigel > On Feb 27, 2016, at 19:11, Mark Sims wrote: > > Also,

Re: [time-nuts] HP 10544A Repair

lacement thermistor. > > Trying to determine the turn over temperature as you > described (which was done with an automated system > in the E1938A) would be extremely cumbersome when > done by hand. It would be a last resort if you fooled > with the pot. > > Ri

[time-nuts] HP 10544A Repair

Hello All, Relatively new to the group, but thought I’d ask for a bit of advice. I have an old HP 10544A ovenized oscillator that was pull from some equipment some time ago because it got too far off frequency to phase lock with the external reference. It looks like the thermistor in the oven

Re: [time-nuts] Trimble Thunderbolt error

Luc, Do you have a reference for this? Nigel > On Feb 15, 2016, at 01:22, Luc Gaudin wrote: > > Hello, > > The issue was known on the Thunderbold for the older firmware version up to > firmware v3.00. > The product will not report the correct extended GPS week number

Re: [time-nuts] Trimble Thunderbolt error

Not sure if it’s locale based, but for reference, my unit seems to be operating normally here in Washington state, USA. Nigel > On Feb 13, 2016, at 17:34, Rob S. wrote: > > > > Hello Group, > > A friend about 2Km up the road from me and I both run the Trimble >