To divide by 5 with a '161/'163 counter, connect
the 8's bit output to the /preset enable input.
Then set the input bits to 12. The counter will
count: 12, 13, 14, 15, 0, 12, 13, 14, 15, 0 ...
This is the fastest configuration. It avoids
external gate delay and the slower carry output.
You can
I love the analysis of the Earth!
Can you do it for Mars too or is the data not available ?
cheers
Tim
On 30/6/20 3:53 am, Tom Van Baak wrote:
[snip]
And if you haven't see it before, I have phase, frequency, and ADEV
plots of earth here:
http://leapsecond.com/museum/earth/
Am 29.06.20 um 20:48 schrieb Gerhard Hoffmann:
eternity, with CMOS being so slow that interoperability with CMOS was
not an advantage.
ooohps, sorry: substitute / interoperability with CMOS /
interoperability with TTL /
___
time-nuts mailing
Hi —
In a parallel life I work as a broadcast radio engineer. An AM transmitter's
hybrid digital control system contains an embedded FEI Nanosync 2 GPS receiver.
The GPS time data appears to suffer from a week 1024 rollover problem, causing
the control system to believe (and broadcast) a
Am 29.06.20 um 18:43 schrieb jimlux:
What logic family might be appropriate for a divide by 5 from 50 to
10MHz, low power, running off 3.3 or 5V?
In the picture is probably what you need, and maybe more.
The left third is a comparator that generates valid CMOS levels from a
vaguely defined
Looks like the AC161 and AC163 are readily available, so they may be
rigged for divide 5. It seems that of the counters surviving into AC,
only binary ones are included, and the oddballs like decade are
considered unnecessary - apparently nobody divides by 10 anymore, except
inside of a
Well, data sheets are out there, but I don't know about the actual
parts. Unfortunately, the 74AC family has far fewer members than the
74HC and others. I think each step in the evolution loses some types
that aren't expected to be high enough in volume for the most modern
applications. For
I just looked around for some AC390s - it appears they may have been
made only by Toshiba and Hitachi, and have gone obsolete. Looks like you
can't just call Mouser to order some up. But, looking at this site, it
appears that a lot exist - at least a million pieces floating around out
there,
You might try the 74AC161, which works to 73MHz at 3.3V or 103 MHz at 5V,
-40 to 85C.
Set the data inputs to DCBA = 1011 and connect an inverter from the carry
output (pin 15) to the Load input (pin 9) to divide by 5. See
http://www.techlib.com/electronics/74161Divider.htm
On Mon, Jun 29, 2020
Hi Lester,
I had this problem with the 5372A at work. As others have noted,
documentation of the CRT unit is for sure leaving a lot to wish for when
comparing how well the rest of the unit is documented. We could however
fairly quickly see the problem, and it turned out that a capacitor had
let
Thanks Don, but I suspect we both have the same manual.
Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
les...@veenstras.com
452 Stable Ln (HC84 RFD USPS Mail)
Keyser WV 26726
GPS: 39.336826 N 78.982287 W (Google)
GPS: 39.33682 N 78.9823741 W (GPSDO)
Telephones:
Home:
Hello Tom,
(and thanks everyone for your advice)
I want to do the same as you: rack mount the oscillators. Elaborate
vibration isolation solutions are not possible in the available space viz 3
to 4 RU.
I have the manufacturer’s test data for the oscillators, plus my own test
data, so I think I
Ed: Like many cards and parts in this unit; Not field repairable, so no
schematics or parts list. I do have the "full" maintenance manual.
It appears to be a OEM Taiwan "Part", the CRT and driver board.
Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
les...@veenstras.com
452 Stable Ln (HC84 RFD
Dave:I have a "not working, parts only" unit coming.
I will see if A17 is working on that unit.
If I get one working, I think I can signal trace to the problem unit, using the
good one as reference
Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
les...@veenstras.com
452 Stable Ln (HC84 RFD
Folks,
A long time ago I worked for a division of Litton Industries. One day
we visited the
Litton Guidance and Control Systems Division, which manufactured Optical
Gyros. Part
of the test facility was a granite slab mounted using isolators on a column
in a hole. I was told that the
Am 29.06.20 um 19:35 schrieb Mark Spencer:
I am also wondering a bit about the possible impact of my 5370B's having a
maximum trigger setting of approx 2.18 volts vis a vis the typical specs for 5
volt TTL signals that typically define a logic 1 as having a slightly higher
voltage ? Would
On 6/29/20 10:41 AM, ed breya wrote:
74AC logic would do it just fine, but needs 5V nominal for full-speed
specs. Lower supply voltage should work, but probably not all the way
down to 3.3V with 50 MHz clocking. The spec sheets should indicate the
possible range.
The 74AC390 can provide
John,
Everything I've read on the subject says that "spooky action at a distance"
does *not*
provide for FTL communications.
Sorry to disappoint- I'd like to see it, too.
Dana
On Sun, Jun 28, 2020 at 7:47 AM John Moran, Scawby Design <
j...@scawbydesign.co.uk> wrote:
> Interesting ...
>
>
On Sun, 28 Jun 2020 12:45:05 +
"John Moran, Scawby Design" wrote:
> They quote - “At the other end of the scale, gravity dominates over very long
> distances,
> while quantum effects vanish entirely at these distances.”
>
> I thought quantum entanglement was valid over any distance -
Rick,
See also the NASA press release from 2005:
https://www.jpl.nasa.gov/news/news.php?release=2005-009
The formal paper about the 3 Gorges calculation is here (4 pages, PDF):
"Time-variable gravity signal during the water impoundment of China’s
Three-Gorges Reservoir"
I just looked at the 74AC390 sheet - it does say it will run to 60 MHz
clocking with 3.3V supply, but that's at 25 deg C Tj. So, it looks
doable, but depends on your desired operating temperature range.
Ed
___
time-nuts mailing list --
Hi:
After a long break I am spending a bit of time looking at my time nuts gear. I
have started looking at the properties of the various 1 pps signals I have
access to.
Other than routing the signals via Coaxial cable into instruments with a high
impedance input (the documentation for some
74AC logic would do it just fine, but needs 5V nominal for full-speed
specs. Lower supply voltage should work, but probably not all the way
down to 3.3V with 50 MHz clocking. The spec sheets should indicate the
possible range.
The 74AC390 can provide divide by 5 directly, with another divide
I am enjoy this Nth degree Vibration Isolation discussion. Countless amazing
tables where I work.
I have been focused on more practical solutions for Vibration isolation of my
rack mount oscillators in my home lab, and I think at that level in some ways
are focused on eliminating resonances as
What logic family might be appropriate for a divide by 5 from 50 to
10MHz, low power, running off 3.3 or 5V?
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
See:
https://futurism.com/how-infamous-hydroelectric-dam-changed-earths-rotation
Of course, readers of this list know that the earth isn't stable to 60
ns/day in the first place. But this is an interesting calculation, at
least to time nuts.
Rick N6RK
On Tue, 02 Jun 2020 05:52:13 +
"Poul-Henning Kamp" wrote:
> I have played with this one:
>
> http://www.rudius.net/oz2m/ngnb/dds.htm
>
> as a synthesizer replacement in the HP5065, but your "dual" configuration
> and the integrated 1GHz "pre-oscillator" would fit that purpose better,
If passive vibration isolation is not good enough active dampening is an option
with a rig like
https://www.herzan.com/products/active-vibration-control/TS-series.html
I was not directly involved, but a team that I shared a lab with bought a gizmo
like that one and it really helped some very
ed breya writes:
> The nicest optical bench I've ever seen in person, was in one of our
> labs many years ago. It was a huge, precisely flat polished granite slab
> about 6-8" thick, about 4x8' or maybe 5x10', mounted on active-leveling
> pneumatic bladders. It was loaded with
29 matches
Mail list logo
