On 7/2/19 4:09 PM, Dana Whitlow wrote:
I've always noted that casual attempts to pick up 60 Hz with small antennas
etc see more harmonics and other trash than actual line frequency. But if
you're in an office environment, why not plug something in? It's quite easy
to build a simple passive
I built a 6 Volt filament transformer into a small metal box and connected
the secondary to a couple of 5-way banana jacks. In addition to the 6 Volt
output, I put a 100KΩ pot across the terminals with the wiper connected to
a third jack. That way, I can have any voltage from 0 to 6 VAC, avoiding
Am 03.07.19 um 01:25 schrieb Tim Shoppa:
Jim, most of us are satisfied to use a 6.3VAC filament transformer to step down
from 120VAC and isolate from the power line.
Exactly. I used an old 6 or 9V AC wall wart and a resistive 1:3 divider
last year when the European grid frequency was low
Hi Bob,
I'm seeing 4.22E-12 as the slope value in the upper right of the TimeLab
phase difference plot. Is that telling me that my DUT is within +4.22ps
/ sec from my reference 1PPS for the 24 hour measurement duration?
I have attached a screen capture that will hopefully make its way
Jim, most of us are satisfied to use a 6.3VAC filament transformer to step down
from 120VAC and isolate from the power line.
Tim N3QE
> On Jul 2, 2019, at 5:56 PM, jimlux wrote:
>
> There's some designs on the list (using a PICPET, for instance) to measure
> the local line frequency and
Hi
The gotcha is that if the duration gets long enough, the numbers on a GPSDO
will get silly small.
You very much have to decide what time duration is appropriate to your system /
application. If you
always run your frequency counter on a 1 or 10 second gate …. you really don’t
care about
I've always noted that casual attempts to pick up 60 Hz with small antennas
etc see more harmonics and other trash than actual line frequency. But if
you're in an office environment, why not plug something in? It's quite easy
to build a simple passive diode clipper/filter that will plug into a
There's some designs on the list (using a PICPET, for instance) to
measure the local line frequency and phase..
but the schemes we've discussed require connecting to the power line in
some way.
What about a non-contact sensing approach? Something you could put in a
box and it would pick up
Hi
The difference in seconds between the start phase and the end phase divided by
the number
of seconds duration gives you the parts in whatever of the error.
If you see 1us ( = 1x10^-6 seconds) of change in a second, you are off by 1
ppm (or 1x10^-6).
If you see 1 us of change in 1,000
Is the slope value for the phase difference shown in TimeLab an average
of the overall data sample duration? The reason I ask is that my service
manual for my RFS says:
/"//A faster way to make the comparison between the reference frequency
and the DUT is to use the time interval measurement
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