Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

Exactly what I have run into. Some systems lock an internal reference to to the incoming system. So that oven has to come up to temp. Then the trigger and interpolators need to warm up and stabilize. So the really right answer is what accuracy are you looking for? Because what I mention above may

Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

Hi, Well, actually there is two methods: 1) Switch reference clock - a switch or mux changes which clock is being used. 2) Lock internal reference to external reference - a PLL lock of the internal reference to the external reference is enabled. For both, the counter core may need to heat up.

Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

Yes, You have removed the reference from the warmup but the input circuits still need time to reach thermal equilibrium for most accurate results On Feb 8, 2018, at 3:34 AM, Azelio Boriani wrote: No warmup needed if the counter switches to the external reference.

Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

Hi It depends a *lot* on the frequency counter. An old style “just count the number of edges” device should be good to go pretty fast. One of the “fry an egg on it” interpolating counters that get into the 20 ps range may well need some time to stabilize. If you are doing ADEV runs, a couple

Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

Hi, On 02/08/2018 08:33 AM, Chris Wilson wrote: > > > 08/02/2018 07:31 > > Does a frequency counter connected to a permanently running (Trimble > Thunderbolt) GPS > disciplined frequency standard need to warm up after switch on before > readings settle? > Just curious, thanks. >

Re: [time-nuts] Does a frequency counter locked to GPS need to "warm up"?

No warmup needed if the counter switches to the external reference. If the counter uses the external reference to lock the internal one then it is better to wait until the internal one is stable, maybe the counter has a standby mode where it appears powered off but the internal reference is active

[time-nuts] Does a frequency counter locked to GPS need to "warm up"?

08/02/2018 07:31 Does a frequency counter connected to a permanently running (Trimble Thunderbolt) GPS disciplined frequency standard need to warm up after switch on before readings settle? Just curious, thanks. -- Best Regards, Chris Wilson. mailto: