Hi
A 1 ns resolution TI counter will do the measuring part just fine. Hitting the
number, is where it gets a bit crazy. A *good* GPSDO might get near that.
Bob
On Oct 3, 2012, at 8:56 PM, Kevin Rosenberg wrote:
> On Oct 3, 2012, at 6:52 PM, Kevin Rosenberg wrote:
>> Nice plot! Yes, I'd have
On Oct 3, 2012, at 6:52 PM, Kevin Rosenberg wrote:
> Nice plot! Yes, I'd have trouble measuring 10E-14 at 10E5 seconds.
Sorry, 1E-14 at 1E5.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/li
And the heat transfer to the fluid s better too. However, boiling has it's
own serious issues.
-John
=
> If you let the water boil, it takes even (much) less.
>
> Tom
>
> - Original Message -
> From: "J. Forster"
> To: "Discussion of precise time and frequency measurement"
On Oct 3, 2012, at 11:15 AM, saidj...@aol.com wrote:
> The CSAC is cheap compared to the reference you need to measure it...
>
> http://www.leapsecond.com/pages/csac/log96872v.gif
Nice plot! Yes, I'd have trouble measuring 10E-14 at 10E5 seconds.
Kevin
___
9 MVA is somewhat bigger than 5 kW.
I was assuming fairly short duration tests, perhaps a few hours, where
open-cycle water is practical.
If you are going to use a water loop, getting rid of the heat is certainly
an issue.
-John
==
> Perhaps, but unless you plan on just draining th
Thanks Don and Allen, it's been that long since I played with radio I
had forgotten- 5.12 is half of 10.240 used to downconvert from 10.7 if
to 455. I had a look through the circuits for my rigs, and my
Eddystone 770r boat anchor uses 5.12MHz to align the various if's, and
multiples of it to align
Perhaps, but unless you plan on just draining the water, you need a liquid to
air heat exchanger (LAHE) to cool the water in your loop. Perhaps for a lab it's
no big deal, but if you intend to operate where it can get cold (needing glycol)
or where there is very limited water supply (remote loca
If you let the water boil, it takes even (much) less.
Tom
- Original Message -
From: "J. Forster"
To: "Discussion of precise time and frequency measurement"
Sent: Wednesday, October 03, 2012 8:14 PM
Subject: Re: [time-nuts] OT question about liquid cooling
It actually takes suppri
On 10/03/2012 03:38 PM, paul swed wrote:
I think it was this thread.
But the actual chip rates derive from a 10.2299543 clock.
We call it 1.023 Mhz but its not. In time-nuttery it matters.
Doesn't that make the use of the signal a bit messy?
Nope. You missed the point of this off the mark i
It actually takes supprisingly little water flow to dissipate 5 kW.
Very roughly 5 kW = 1250 cal/sec (4.18 J/cal)
so, for a 1 C degree = 1.25 liters/sec
at 50C degrees = 25 mL / sec. = 1.5 L/min.
-John
==
> BWIWY (back when I was young) we needed a dummy load for a super
BWIWY (back when I was young) we needed a dummy load for a supercomputer (think
Cray YMP size) that drew many many kw.
Our test load was about 250' of 3/4" copper tubing coiled at about 12" dia and
1" spacing. The load was varied by changing where the + and - leads were bolted
onto the coil wi
My day job is large industrial power supplies. The test racks have large
resistive loads with big fans exhausting to the outside. Cheap & simple.
Safety is by several strings of temperature cutouts wired in series. We
usually get work experience students in to wire them up.
Tip: to make a funny va
5.12MHz is often used as the reference for PLL channelised radio receivers.
Alan G3NYK
- Original Message -
From: "Don Latham"
To: "Discussion of precise time and frequency measurement"
Sent: Wednesday, October 03, 2012 6:28 PM
Subject: Re: [time-nuts] Oscillator frequency?
Hi K
Hi Ken: I have two of these, and had the same problem some years ago
(see archives time-nuts). Nothing seemed to need this frequency. Fast
forward to present. I'm using an ICOM 260A 2m all-mode xceiver for if in
a 13 cm moonbounce system. The xtal frequency for the basic synthesizer
in these units
Please don't adjust the dampening, you might find it floating...
adjust the damping if you need to change the settling time.
Yours in pedantry-one of my hot buttons :-)
Don
Bill Dailey
> ok.. So that may very well be true of this unit. Electrical tuning is
> 3E-7 0 - 5v (+/-). It also lists a
Very nice plot Tom!
Did you thermally insulate the CSAC to get this kind of performance?
bye,
Said
In a message dated 10/3/2012 09:24:54 Pacific Daylight Time,
t...@leapsecond.com writes:
> Many thanks and for all of your help thoughts over the years. I'll look
forward to the day and
Thanks Said. This is a learning experience but it is fun watching it settle
down. I will stop fiddling with the settings and just let it do it's thing. I
am watching the output with my qs1r direct digital to spectrumlab. This way I
don't have to worry about any audio glitches. I have been re
Who would want to jam GPS? Haven't heard this one:
Fishing party boat captain - knows where to find the fishing spots
after years of experience. Rotates use of the spots so as not to
over-fish them. Arrives at his spots to find fishermen who had gone
out with him and captured the GPS locations of
Hi
NTP server? Time tagging remotely collected data? Large area industrial
automation?
Generally as you relax the timing requirement, the number of applications
goes up quite a bit. If all you need is a few hundred ns (but under a few
microseconds), a bare timing receiver is a fine thing.
Bob
> On 10/2/12 10:35 PM, b...@lysator.liu.se wrote:
>>> On 10/2/12 2:36 PM, saidj...@aol.com wrote:
Hello Paul,
thanks much for the feedback!
Yes, we think we have identified a nice combination of oscillators,
GPS,
and firmware that seems to work pretty well. The GP
5KW of power but that is only 1/4 of the spec. What temperature will
the loads operate at? It is quite hard to cool anything to ambient
with water. The cooler the operating point the larger the heat sink.
Using a very oversize heat exchanger s not unreasonable of you want a
relative low tempera
Let me just say that that's flea power!
I saw some 80watt jammers being sold for movie theaters and churches.
There is some very "black market" items from China, via Hong Kong and can
arrive at your doorstep in just 4 days via DHL! What's out there would scare
you.
Been dealing with the fall ou
> Many thanks and for all of your help thoughts over the years. I'll look
> forward to the day and I can afford a GPS disciplined CSAC.
>
> Best,
>
> Kevin
The CSAC is cheap compared to the reference you need to measure it...
http://www.leapsecond.com/pages/csac/log96872v.gif
/tvb
On Oct 2, 2012, at 1:39 PM, saidj...@aol.com wrote:
> 1) calibrate the internal 100MHz vectron OCXO using a small screwdriver,
> this is not really critical though as the unit does not really function as a
> frequency counter.
>
> 2) Calibrate the power supplies for proper voltages if necessar
Hello all,
Please excuse me for the OT, but since this list is plenty of very
knowledgeable colleagues, I'm tempted to ask...
I need to cool several resistive loads, in the order of 5kW, and I plan
to use a cold plate and a liquid-to-liquid heat exchanger like the
Lytron LCS-20, but this uni
Doc,
You are on the right track, efc scale affects SD as you can see.
The phaseco parameter is used to push down the average TI to 0ns. Higher values
push faster.
If your ocxo is still drifting (aging and or retrace) it will take about 48
hours for the aging measurement and correction to kick
Some 20 to 25 years ago a law enforcement agency in California was
experimenting with GPS in its patrol cars. It required that the officer press
key to report his/her location. It also had a pinging capability that the
officers didn't know about. Through pinging, it was discovered that a number
for Jim Lux --
Thanks for the comments -
Yes, if the receiver is linear (e.g. say you do a sliding code
correlator and slide until you get the peak, with the correlator using
a
multiplier)...
That is how the system I did worked. It could defeat an on-frequency
jammer that
was 20 db stronger
Yes, it would be interesting to run such a GPS receiver: maybe there are
numbers of points to follow the signal processing.
On Wed, Oct 3, 2012 at 3:12 PM, paul swed wrote:
> Boy have to say no clue and not a very useful frequency. Would it make a
> nice bookend?
> Paper weight. Glue a watch to
On Tue, Oct 2, 2012 at 9:40 PM, Ron Ward wrote:
> Hi:
> Other than a terrorist, who would want to jam GPS?
A delivery truck driver. His boss installs a GPS tracker on the truck
and the driver wants to take a three hour lunch break. This is a
pretty common scenario and likely the way most GPS j
I think it was this thread.
But the actual chip rates derive from a 10.2299543 clock.
We call it 1.023 Mhz but its not. In time-nuttery it matters.
Doesn't that make the use of the signal a bit messy?
Regards
Paul
WB8TSL
On Tue, Oct 2, 2012 at 10:30 PM, Jim Lux wrote:
> On 10/2/12 3:39 PM, j
One of "fine" units from Hong Kong delivered +32dBm of wide-band FM noise
centered on 1575MHz!!! Just a tad more range than 10m I would expect.
-Brian, WA1ZMS
(sent from my over-priced iPad3)
On Oct 3, 2012, at 8:44 AM, shali...@gmail.com wrote:
> It is not that hard to transmit broad band noi
Boy have to say no clue and not a very useful frequency. Would it make a
nice bookend?
Paper weight. Glue a watch to it and you have at least time. ;-)
Regards
Paul
WB8TSL
On Wed, Oct 3, 2012 at 9:07 AM, ken johnson wrote:
> Hi, I have a tcxo that I recovered from a very old, suitcase-sized gps
Hi, I have a tcxo that I recovered from a very old, suitcase-sized gps
receiver some years ago. The oscillator is marked "ERC
Eros-750-MA110", with an output frequency of 5.119155MHz. I have tried
to think of a use for for it but failed. I played with the numbers but
could not find anything useful,
Of course, that only works when you actually need a GPSDO, but what is the
point of a GPS timing receiver if not to discipline a high quality oscillator?
Didier KO4BB
Sent from my Droid Razr 4G LTE wireless tracker.
-Original Message-
From: Jim Lux
To: time-nuts@febo.com
Sent: Tue, 0
On 10/2/12 10:35 PM, b...@lysator.liu.se wrote:
On 10/2/12 2:36 PM, saidj...@aol.com wrote:
Hello Paul,
thanks much for the feedback!
Yes, we think we have identified a nice combination of oscillators, GPS,
and firmware that seems to work pretty well. The GPSTCXO units cannot be
compared to a
It is not that hard to transmit broad band noise over the entire GPS channel
and clobber it entirely.
Didier
Sent from my Droid Razr 4G LTE wireless tracker.
-Original Message-
From: johncr...@aol.com
To: time-nuts@febo.com
Sent: Tue, 02 Oct 2012 9:33 PM
Subject: Re: [time-nuts] GPS
Hi all
Another production run – the last - of the “ThunderBolt Display” is being done.
Thought I would give it quick mention here, in case any ThunderBolt owners were
interested, as some TimeNuts subscribers obtained a display last in the first
production run.
For details, pictures, video and
ok.. So that may very well be true of this unit. Electrical tuning is
3E-7 0 - 5v (+/-). It also lists a digital tuning range of +- 3Hz at
10MHz. Correct me if I am wrong but that appears to mean 3Hz electrical
and 6Hz digital tuning range. I am not doing digital tuning but thought I
would t
39 matches
Mail list logo
