On Tue, Aug 11, 2020 at 10:27:33PM -0400, paul swed wrote:
> Just saying they work for all those atomic clocks for $10.
Those don't give a damn about 60 KHz delay/phase provided it
doesn't change very fast (as it wouldn't due to thermal effects).
But monitoring frequency or
How do the small AM WWVB clocks work then. They use the 60 KHz crystal and
they don't actually do anything special. In measuring those clocks they are
about 2-6 hz wide. On the spectracoms the crystal is huge. Looks like a HC6
but 3" long. About 1-2 Hz wide.
Using the same small crystals in BPF
I'm seeing more than 100mV p-p right now (7:09 PM) (2309 UTC) on the output of
my preamp from the east coast of New Jersey, 1622 miles east of WWVB.
During my early days of WWVB experimenting, I found the signal is easier to
spot (since it's buried in noise) if the scope's horizontal sweep is
On Tuesday, August 11, 2020, 07:14:12 PM EDT, Bob kb8tq wrote:
> The problem with the crystal is that it has a temperature coefficient. As a
> narrow band filter, it will have a *lot* of delay. Crystal resonance moves
> (with temperature) and the delay changes.
I agree. The crystal needs to be
Hi
The problem with the crystal is that it has a temperature coefficient. As a
narrow band filter, it will have a *lot* of delay. Crystal resonance moves
(with temperature) and the delay changes.
How much delay depends a lot on a bunch of fiddly details. A 10 to 100 Hz wide
bandpass could
Should add that on the East Coast the signal is about 10 uv. On the large
10' X 10' loop I get about 63 uv during the day. That loop at night can
easily hit 1000 uv.
Regards
Paul
On Tue, Aug 11, 2020 at 3:37 PM paul swed wrote:
> Mark
> His antenna hit a preamp as I recall about 20 db of gain.
Mark
His antenna hit a preamp as I recall about 20 db of gain. To see something
on a scope add 40 more db approx. Unfortunately a purely broadband solution
will show 40 db of pure garbage these days. Using the 60 KHz watch crystals
$2.00 for 20 out of China you can most likely find a reasonable
Hi everyone,
On 8/6/20 5:55 AM, jimlux wrote:
On 8/5/20 4:18 PM, Mark Haun wrote:
I wonder if someone maintains a directory of ionosondes. Seems like
waste/duplication to have every interested party set up their own,
instead of piggy-backing on what's already out there. There's also the
Hi Detlef,
On 11-Aug-20 3:46 AM, Detlef Schuecker via time-nuts wrote:
> you do not necessarily need a variable ( physical ) oscillator. You mix
> the signal down in the digital domain. A 'digital local oscilator' is a
> mere complex value, which is rotated and the power is adjusted:
My
Hi,
you do not necessarily need a variable ( physical ) oscillator. You mix
the signal down in the digital domain. A 'digital local oscilator' is a
mere complex value, which is rotated and the power is adjusted:
#define CMUL(_a,_b,_c) \
{ _c.re = _a.re*_b.re-_a.im*_b.im; \
_c.im =
Ray,
I don't see a crystal filter. There is a 16 MHz crystal, but that's for
the processor.
"Inside the La Crosse 1235UA UltrAtomic Radio Controlled WWVB (Atomic)
Wall Clock"
http://leapsecond.com/pages/ultratomic/
"ES100 datasheet, including block diagram, application circuit, and theory"
Does the La Crosse UltrAtomic clock actually use a crystal filter or do
they digitally filter the signal? Has anyone ever looked inside of one
of the clocks? Just curious.
Ray
AB7HE
Original Message
Subject: Re: [time-nuts] WWVB SDR discussion
From: Mark Haun
Date: Mon, August
12 matches
Mail list logo
