Also see this
https://www.bicsi.org/uploadedfiles/bicsi_conferences/fall/2012/presentations/CONCSES_4C.pdf
Content by Scott
Typos by Siri
On Jun 18, 2018, at 5:51 PM, Charles Steinmetz wrote:
Graham wrote:
> If you want to protect your installation from lightening, then there is a
> body of
I’ve been on towers and decided to exit that
location as the bleed
process became audible. It very much does happen. It simply is not a 100% sort
of thing.
Bob
> On Jun 19, 2018, at 12:01 PM, Scott McGrath wrote:
>
> Probably the easiest and most economical grounding system is the ha
does not make sense for
the other…. A “full up”
protection setup can easily run into hundreds of thousands of dollars. I’d much
rather spend that kind of money
on a Maser … or two …. or three :) …. this is TimeNuts after all ….
Bob
> On Jun 19, 2018, at 10:56 AM, Scott McGrath wr
Does anyone recall off hand the GPS EPOCH startup fix for the DC-XL
I’m away from lab and notes trying to get one running for a friend.
As I recall it was on the order of func 12. F96
But with these units you dont want to be entering random data via keypad
Content by Scott
Typos by Siri
The 18” inch requirement is partially for damage resistance and partially to
ensure adequate soil moisture for conductivity.
Content by Scott
Typos by Siri
On Jun 19, 2018, at 10:50 AM, jimlux wrote:
On 6/18/18 6:39 PM, Glenn Little WB4UIV wrote:
> To do the grounding correctly, all
True but if you use a good switch or PIN 90 db of isolation is easily
achievable. Yes the spur is still there but it’s 90 down and will not affect
ADEV as badly.
You could drive it further down with two switches with the alternate standard
connected to 1 port and a termination to the other.
Build one yourself, Detector diode on primary RF input when output drops use
a rf relay or PIN diode switch to fail over to backup standard.All thats
needed is a crossing detector and relay / switch driver
Yes there would be a momentary hit but it would work.
Content by Scott
Typos by
WRT my sextant comment, How many pilots or sailors can navigate by ‘shooting
the sun/stars’. They have become dependent on precision navigation systems.
Which of course feeds the thinking by empty suits why do we need lighthouses,
buoys, VOR’s and airway beacons because we have the ‘god
And with dependence on GPS we have created a serious vulnerability as too many
critical pieces of infrastructure are dependent on a SINGLE precision timing
and positioning system.
I can use a sextant and have a copy of Bowditch.But they only work on clear
days and nights.
if GPS goes down
This has ‘empty suit’ written all over it ,’move it to the $BUZZWORD
Yes the LORAN shutdown was more impactful from a time transfer PoV but the NIST
transmitters provide a crude backup and valuable scientific data with a long
baseline
In NH we’ve had an unusually severe summer WRT weather
using time as the public key
and exchanging encrypted routing packets were
isolated.
Jim Cotton
From: time-nuts on behalf of Scott McGrath
Sent: Thursday, August 30, 2018 10:42:45 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time
One does not get the same instantaneous accuracy that one gets from GPS but
with a long baseline the offsets to your site can be determined.With eLoran
you can get similar levels of accuracy as the old Austron monitors used to
prove
Content by Scott
Typos by Siri
On Aug 30, 2018, at
The port of Long Beach CA was jammed wrt GPS for several months by a
malfunctioning 29.95 TV preamplifier on a boat.
GPS was completely unusable when this unsuspecting guy was watching TV on his
boat.
He had quite the surprise when the coasties with guns showed up.
The fact is civillian GPS
As Brooke notes while low frequency jammers are possible, practicality is
another matter, All it takes to jam a city scale area is a box the size of a
pack of cigarettes.Because the GPS signal is very, very weak.
As an intentional denial put a couple hundred on stray animals.Now track
There was a paper published when NASA did something similar for LC39 and the
VAB.Anyone have a copy because the link i have is dead.
As I recall it was some trick and compensating for thermal effects on the fiber
itself was a large part of the effort.
On Sep 1, 2018, at 5:29 AM, Magnus
t; So, interns of “the world ends if / when WWVB turns off” … not so much.
>
> In terms of the initial question, GPSDO’s in general are pretty good at
> handling the typical
> jamming they might run into.
>
> Bob
>
>
>
>> On Aug 31, 2018, at 3:52
tever it's now
called) in your area. Jamming does not always have to be in-band to be
effective.
Dana
> On Tue, Sep 4, 2018 at 1:11 PM Scott McGrath wrote:
>
> My TrueTime DC-XL has lost lock since yesterday as has my Z3805 and my
> car’s onboard GPS will not lock since the 2’nd.
require. It simply is not and can not do the job. The world
has moved *way*
past the sort of timing it can actually deliver.
Bob
> On Sep 6, 2018, at 6:35 PM, Scott McGrath wrote:
>
> Actually we DID have a radio based system that provided sufficient accuracy
> it was c
.
On Sep 6, 2018, at 8:44 PM, Scott McGrath wrote:
Gee, thats strange especially for those of us who ran the Austron comparitors
to check our local standards against the LORSTA’s
On Sep 6, 2018, at 8:04 PM, Bob kb8tq wrote:
Hi
No, eLoran *never* on it’s best day could ever deliver the kind
This is precisely the scenario even a short GPS blackout of 1-2 weeks would
cause. Its not that GPS is not the finest time transfer system ever devised.
Its that with the loss of legacy systems we’ve lost the ability to degrade
gracefully.
With a eLORAN system cell networks during a
have a generator
with magneto ignition so I should be good to go when the end-of-the-world
arrives.
> On Saturday, September 8, 2018, Scott McGrath wrote:
>
> Actually
>
> I do have much of my equipment inside a shield room, not for tinfoil hat
> reasons but to keep experim
Actually
I do have much of my equipment inside a shield room, not for tinfoil hat
reasons but to keep experimental systems from causing interference and to
eliminate existing RF sources in the 800 Mhz to 8 Ghz range as error sources in
measurements.
If one is concerned there are lots of old
And there is the other significant vulnerability since GPS is a MILITARY system
the DoD can take it offline for any reason at any time.
Leaving civilian users with nothing,
If its a national security threat its likely the other GNSS systems will be
unavailable as well.
On Sep 6,
adequate.
=
Now, if this is headed off into a “the government is coming to break down the
doors and take away all my toys sort of thing. That’s very much *not* a Time
Nuts topic.
Bob
> On Sep 6, 2018, at 11:34 AM, Scott McGrath wrote:
>
> And there is the other significant vuln
Just ask the NY Port authority how ‘easy’ knocking these jammers offline is.
Usually done by vehicle to vehicle inspection with a SA.
And yes the day job all too frequently searching for and identifying
interference sources.
One of the more interesting ones was a halogen leak detector wiping
Excellent point on LEGAL time, The problem is as always is GPS is the new
shiny object.
You mentioned earth based hostile actors. But a really large solar flare or
CME has the potential to take out or severely degrade ALL the GNSS systems.
Something on the order of the ‘Carrington Event’
A DIY radio distribution system is not secure and traceable to NIST/USNO even
if the source is GPS.
On Aug 29, 2018, at 7:52 PM, Scott McGrath wrote:
Excellent point on LEGAL time, The problem is as always is GPS is the new
shiny object.
You mentioned earth based hostile actors
on the
air.
Bob
> On Sep 6, 2018, at 9:08 PM, Scott McGrath wrote:
>
>
> As to eLORAN, you can deny positioning but maintain timing service simply by
> modifying the GRI and since eLORAN is software based thats not a difficult
> change.
>
> Navigation receivers go into f
I can do it, on east coast though
Content by Scott
Typos by Siri
On Jul 12, 2018, at 6:13 PM, Rhys D wrote:
If you get stuck, I can help. I am in New Zealand though, so postage may be
a concern.
On Fri, 13 Jul 2018 at 6:36 AM, wrote:
> Hi,
>
> I remember a few that had machine shops
For timing use ideally it should be above the roofline by at least several feet
otherwise satellites close to the horizon will be not be visible.
The generally preferred antenna is the Agilent/Keysight/Symmetricom. 58504A
antenna also any outdoor antenna made by Trimble or TrueTime as long as
Racal overall has a reputation for making very high quality instruments,
Since the OCXO is an option,and the price is right on the DA, I’d
probably buy it.
Also thinking since its an option the OCXO can probably be switched out of
circuit or removed entirely.
Im guessing Racal thought
I use NI USB interfaces, They are reliable process ATN messages and of course
have the vast programming library associated with NI interfaces.
Used ones can be found on the well known auction site for 250-400 bucks.
Make sure you get the BLUE ONES the Brown ones are USB 1.0 and are
, 2018 at 7:01 AM, Scott McGrath wrote:
>
>
>
> Without precision timing there is no telephone network, cell phones or
> internet. And that only became true in the last 20 years or so as long
> haul networks went from FDM on coaxial cable to TDM on fibre.
>
The Internet is
Strangely enough there are these devices called ‘computers’ which are rumored
to be able to perform measurements and mathematical calculations.
One of these ‘computers’ might be profitably employed to perform the necessary
measurements calculations and deliver a useful output,
Employing a
I/We track down things that jam weather radars. Mostly WiFi access points
misconfigured.
Which share many of the characteristics of GPS jammers
1 - small low powered
2 - one can ruin a pilots entire day
3 - distributed
4 - can literally be anywhere
Stuff like this is why FCC blocked anyone
Mechanical chonometers are still rated and the offset applied. This was
probably the earliest application of the offset with respect to the time
standards of the day. I.e. Greenwich and USNO among others.
Content by Scott
Typos by Siri
On Jan 12, 2019, at 5:15 PM, Jim Harman wrote:
I
I’d go with the old standard the Fluke 87 lifetime warranty, true RMS AC
measurements, rugged and 4-1/2 digits
Content by Scott
Typos by Siri
On Mar 23, 2019, at 8:05 AM, Jim Palfreyman wrote:
Hi all,
I think I'm in the market for a new digital multimeter.
Could I have some
You and the builder of this clock win the internet today!
Content by Scott
Typos by Siri
On May 21, 2019, at 1:54 PM, Mark Sims wrote:
Everbody needs one of these...
https://www.ebay.co.uk/itm/The-Covert-Bombe-Clock-from-Bad-Dog-Designs-Codebreaking-in-Secret/123775434764
Ive got one as well, i’ll look at it over the weekend but as I recall these
are all string outputs which require parsing. The problem with fault and alarm
is without manual dont have a list of possible faults and alarms
Version is easy its the same as displayed on LCD
Content by Scott
Typos
Have you checked the HV supplies?
Content by Scott
Typos by Siri
> On Nov 3, 2019, at 2:04 PM, AC0XU (Jim) wrote:
>
Time Nuts-
This 5061B was working fine until a recent power failure, after which the unit
would not come on line (alarm light stayed lit).
Major symptoms now:
Beam I ;
Its not so much the noise from the interface its the USB device itself i’d
worry about as USB 3.0 generates RF signals up to 3 GHz. And also has fairly
strong signals in the 2.4 GHz ISM band.
Content by Scott
Typos by Siri
> On Dec 4, 2019, at 12:07 AM, David Van Horn via time-nuts
>
ida Van Horn via time-nuts
> wrote:
>
I'm not too worried up there, my receivers are working at 457 kHz.
-Original Message-----
From: Scott McGrath
Sent: Wednesday, December 4, 2019 12:14 AM
To: Discussion of precise time and frequency measurement
Cc: David Van Horn
Subject:
-417-1345 x110
email: david.vanh...@backcountryaccess.com
-Original Message-
From: time-nuts On Behalf Of David Van Horn
via time-nuts
Sent: Thursday, December 5, 2019 6:15 AM
To: Scott McGrath ; Discussion of precise time and
frequency measurement
Cc: David Van Horn
Subject: Re: [
4 pin xlr is also standard for pro audio/video. So you might want to use the
same pin configuration as the ‘standard’ so you can use the large variety of
accessories available.
Content by Scott
Typos by Siri
On Oct 22, 2019, at 7:42 PM, "n...@lazygranch.com" wrote:
Glad I read all the
I have a similar crimper for lugs it works nicely, the cross section is the
proof of the pudding so to speak.
Content by Scott
Typos by Siri
On Oct 8, 2019, at 12:14 AM, Mark Goldberg wrote:
At a risk of having you folks tear it apart, here is my poor man's guide to
getting good crimps on
+1 for powerpole connectors and purchasing a proper ratcheting crimper for the
powerpoles. AND being willing to discard marginal crimps.
Content by Scott
Typos by Siri
On Oct 4, 2019, at 5:38 PM, Bill Dailey wrote:
There are locks you can get. I saw them on Mountain West today.
Bill
As to crimping tools it’s important to use the correct power pole tooling as
the alignment of the crimp is critical to contact insertion.
Ive found the West Mountain Radio tool to be good for the smaller powerpoles
I’ve got the Anderson crimper for the 75 amp powerpoles.
Anything larger -
As one who owns a 105 i had the battery properly rebuilt and basically have it
on low rate charge and periodically discharge the battery
When rebuilding a 105 battery it’s important to replicate its characteristics
Remember HP also intended I believe that the battery would also serve as a
Remember you ‘beat’ a clock using a audio amplifier and a standard signal there
is a screw which adjusts the tension on the escapement spring, Now you could
use a reduction drive to turn the screw or take direct control of the
escapement spring using the mechanical ‘ticks’ of the escapement
I hope we finally light up eLoran and soon not only is it needed for time
transfer. As a pilot there have been way too many GPS outages and the ADS-B
peer to peer system is totally dependent upon precision positioning signals
from GPS.
It’s unsettling to be doing a GPS approach only to be
Lit up the Austron Monitor And the 117A looking forward to AOS
Content by Scott
Typos by Siri
> On Feb 10, 2020, at 9:56 AM, paul swed wrote:
>
Well good news on the old LORAN C receivers all are fine. Turned out I had
a single channel driver bad in the distribution amplifier. Simply used
Supposedly lowering Tx power on terrestrial network from +23 DBm to +9.8 DBm
will make everything better. Ajit Pai is listening only to carriers and
ignoring DoD who is stating it will significantly degrade and/or make useless
the GPS system.
Not to mention ADS-B which was installed at
system.
And say goodbye to our GPSDO’s
On Apr 17, 2020, at 2:59 PM, Bob kb8tq wrote:
Hi
Was that +9.8 or -98 dbm ? :)
At -98 they probably *could* coexist with GPS. Not real clear how well there
system would work at that level though.
Bob
> On Apr 17, 2020, at 1:37 PM, Scott McGr
> the ambient noise anyway.
>
> That, and isn't 5G intended for (among other things) mobile devices?
> That probably will be trying to use GPS etc as well. Shoot in own foot
> time I think.
>
>
> Regards.
>
> Dave B.
>
>
>
>> On 18/04/2020 00:56, time-nuts-
Rather than custom casting a structure you might want to consider use of a
precast concrete septic tank or transformer vault as cost will be much lower.
You will also need to consider waterproofing the tank it already has a layer of
waterproofing but a couple of additional layers will probably
Usually in analog quartz clocks oscillator frequency is around 32khz
Content by Scott
Typos by Siri
On Nov 26, 2021, at 9:09 AM, Peter Torry via time-nuts
wrote:
Hello list,
I am restoring a Seiko Quartz QM10 Marine Chronometer that is currently
inoperative. Preliminary investigations
I’m going to bring up jamming here as 1) i live directly under a military air
route. 2) a local OTR trucker brings regularly scheduled jamming when he
leaves/arrives home.
Your client could also be in proximity to a ‘prepper’ who is running a GPS
jammer to prevent ‘three letter agencies’
57 matches
Mail list logo
