mple. The shapes for the electrodes seems to have been worse.
>
> Cheers,
> Magnus
>
> On 02/03/2018 11:34 PM, Bob kb8tq wrote:
>> Hi
>>
>> The “BVA” part of the name refers to the slots machined into the crystal
>> blank
>> to manage the mounting s
Hi
The “BVA” part of the name refers to the slots machined into the crystal blank
to manage the mounting stress on the resonator. Both the “plated on the blank”
and the “electrodes off blank” versions are legit BVA approaches. Indeed the
electrode off the blank version is the more expensive (and
Hi
There may be “tweaks” to get the noise shaping working better on the 10 MHz
input. Some PLL
chips have pre-multipliers for the reference to improve things…. the magic
apparently works better
with a fast input …(and yes, there are good reasons why)
Bob
> On Jan 29, 2018, at 3:38 PM, John Ack
Hi
Questions are good, it’s how you figure things out. We’re talking about a
“practical” timing device design. It’s not as crazy a topic as it might seem.
Some basic math:
You get to a million seconds at about 11.6 days. A millisecond error over that
period is one ppb. If you are off 1 ppb at
Hi
As mentioned multiple times in the archives. As you get into the single digit
milliseconds, the human eye simply can’t keep up. A watch that is 1 ns off
and one that is 1 ms off are both “good enough” if you are looking at it with a
normal eyeball.
>From a design standpoint 1 ms / day / we
Hi
It would be *very* interesting to see what happens if you sync it up to a 10
MHz input ….
Bob
> On Jan 28, 2018, at 7:23 PM, John Ackermann N8UR wrote:
>
> I received the Si5340A evaluation board from Digikey on Friday and fired it
> up yesterday. I used the SiLabs "ClockBuilder" softwar
Hi
A GPS PPS output will (most likely) be more accurate than the CSAC
each time you go back to dock with the charger. A GPS module to do
everything you would ever want to do is a sub $100 sort of item. You
would still need a bit of hardware to “glue” things together (but not a lot)
and some code
Hi
There’s a cluster of time and frequency outfits up in the Salem area. Some have
been there for a *long* time indeed. The EG&G / Perkin Elmer Rubidium guys
are one that comes to mind. MTI is a bit further north, but still in the same
side
of the Boston urban sprawl.
Bob
> On Jan 27, 2018,
Hi
Yes, I have set up a CPU to dump all the data from a CSAC. Everything
they list in their data sheet can easily be dumped via a standard UART
interface. The serial protocol works exactly the way they describe.
There is no “built in clock” so no ability to dump the time and date. You
can “im
Hi
“Included software” on the CSAC is a pretty short list …. There
is not much past the “stuff” to set it on frequency and read out
a few alarms.
One thing that gets into a lot of these projects:
We are Time Nuts and spec things in terms of time. This error
over that period is some specific nu
Hi
I suspect that a lot of people are wondering who the buyer might be ….
Bob
> On Jan 26, 2018, at 6:27 PM, Clint Jay wrote:
>
> Perhaps of interest to the list
>
> https://www.theregister.co.uk/2018/01/25/microsemi/
>
> --
> Clint.
>
> *No trees were harmed in the sending of this mail. H
Hi
The target application is NTP with the PPS probably coming in via a RS-232
serial port.
Anything that jitters less than 200 ns is probably going to look “same / same “.
Bob
> On Jan 26, 2018, at 6:48 PM, Bryan _ wrote:
>
> Thanks, forgot I have a Jupiter-T (D-120?) in my parts box , on th
Hi
Which ever you can get for the least money. Anything much over $10 is probably
“over budget”.
Bob
> On Jan 26, 2018, at 3:57 PM, Bryan _ wrote:
>
> Which would be the preference as timing receiver Motorola Oncore or a Trimble
> Resolution T ?
>
>
> -=Bryan=-
>
>
> ___
Hi
One way or the other you will need some “smarts” to do aging compensation.
That implies adding a CPU of some sort to the “system” you are building. There
is no built in subsystem on the CSAC that will do any of this for you. You also
need some sort of display for your “wrist watch”. Having the
Hi
The “ppb” number in this case is the temperature performance. Indeed, that is
“pretty close” to
the temperature performance of the CSAC. Aging is rated at 50 ppb / year.
That’s a bit further
out than what a typical CSAC will do.
In either case, if you let the beast run for a year, it is ag
Hi
The CSAC (like any vapor cell standard) has a drift (aging) process. That’s
just the way it works. It is at a *much* lower rate than a crystal oscillator,
but
it is the same sort of idea. It is one of their basic differences from a Cesium
beam tube.
Can you “estimate” aging in advance? Eve
Hi
> On Jan 25, 2018, at 5:47 PM, Ronald Held wrote:
>
> Nigel;
> Will read the PDF carefully.
> Ronald
>
>
> "if it runs for years (or even months)" sounds like an informed comment:-)
>
> When searching for some data recently I came across a report which
> might be relevant.
>
> "A
Hi
You can mod toaster ovens, they work ok, EEVB has *lots* of info on that. When
you buy
your PCB you can get solder stencils at the same time. Bought as a package they
are in the
$10 or so range. Without buying the boards with them, I’m sure the price goes
up a bit. The
metal ones are a bit m
018, at 3:42 PM, jimlux wrote:
>
> On 1/25/18 11:20 AM, Bob kb8tq wrote:
>> Hi
>> One of the unique features of underwater timing is that the sea bottom
>> temperature
>> (once you get well away from a coastline) is *very* stable. In some
>> deployments, the “r
Hi
Just to be clear, the current data sheet has the temperature range back to
-10 to +70C. They most certainly had a major headache on their hands for
several years straightening things out. I have not seen any complaints about
the “new” (post rework) version of the part.
Bob
> On Jan 25, 2018
Hi
One of the unique features of underwater timing is that the sea bottom
temperature
(once you get well away from a coastline) is *very* stable. In some
deployments, the “random”
nature of ambient temperature that we fight all the time in the rest of the
world, simply is not
present. The devic
Hi
> On Jan 25, 2018, at 2:02 PM, wb6bnq wrote:
>
> Hi John,
>
> After looking at the data sheet, it seems way more involved then just making
> a carrier board for it. Besides the power supply requirements, various
> design selections would dictate different circuit layouts for different
>
Hi
> On Jan 25, 2018, at 12:39 PM, gandalfg8--- via time-nuts
> wrote:
>
>
>
> Hi
>
> The CSAC spec sheet calls out an aging rate of 0.9 ppb per month as
> “typical”. There is also a temperature spec of 0.4 ppb. If both are correct
> for your sample (*and* aging is linear ) you would be ou
Hi
The CSAC spec sheet calls out an aging rate of 0.9 ppb per month as
“typical”. There is also a temperature spec of 0.4 ppb. If both are correct
for your sample (*and* aging is linear ) you would be out by roughly 10 ppb
per year. There also is a voltage stability spec that might be impacted
Hi
The original RbXO was not a whole lot bigger than the Rb. The CSAC
is a *lot* smaller than the Rb’s of that era. The TCXO’s and OCXO’s today
are a lot smaller as well. I’d bet you could do it in < 2X the volume of the
CSAC with a pretty good OCXO and < 1.2X the volume with a precision TCXO.
Bo
Hi
The T software does support locked position. If your antenna location is so bad
that this is of any use …. move the antenna. I can get full coverage with a
modern
uBlox from a chair in the family room.
A bit more information: If you are in an “urban canyon” (or maybe a real
canyon)
then i
Hi
I’m guessing there was a question to me that somehow got lost in the world of
ones and zeros ….
My comment was in terms of temperature stability. The CSAC has a temp stability
specification of +/-4x10^-10 over -10 to +70C. There are TCXO’s that will get
below
5x10^-9 over that range and use
Hi
For something portable, the good old RBXO approach might well be worth
considering.
Bob
> On Jan 22, 2018, at 3:05 PM, Ronald Held wrote:
>
> Magnus:
> I wanted one since they were announced in 2005, AFAIR. Incorporated
> into a watch was my first choice, but that price is out of range.
Hi
It is doubtful that the pc board has an RS-232 to TTL converter onboard. The
module it’s self
“talks” TTL levels rather than RS-232 levels. RS-232 to TTL adapters are dirt
cheap and easy
to find on eBay. Make sure you get one that has control lines along with the
basic RX and TX
functions. (
Hi
The “compelling case” for the CSAC is the combination of low power and long
term stability.
You can get OCXO’s that run less power. A TCXO that uses less power is trivial.
Temperature
stability wise, there are TCXO’s that get pretty close (= factor of 10) to
overlapping with the CSAC.
Ther
Hi
What level of stability are you trying to measure?
What sort of offset frequency are you running?
What kind (phase noise / spurs / adev) offset oscillator are you using?
What sort of limiter are you running with what sort of pre filtering?
We have run around on a lot of generalities. You
Hi
The quality of the offset signal source matters in a DMTD system. If you are
using
a “noisy” source you will have trouble with the data. You also will have
trouble if the
offset signal is correlated in some way to one of the DUT signals.
Bob
> On Jan 20, 2018, at 3:43 AM, tim...@timeok.it
n diodes can degrade the timing jitter
> substantially (tens of picosec for HCMOS).
>
> Bruce
>> On 20 January 2018 at 14:34 Bob kb8tq wrote:
>>
>>
>> Hi
>>
>> Unless you really beat on the thing for days on end, you can do without the
>> 330 ohm a
P compatible daughter board.
>
> Bruce
>> On 20 January 2018 at 12:37 Bob kb8tq wrote:
>>
>>
>> Bob
>>
>> With a 1V p-p sort of output, a simple matching network will get you into
>> the 4 to 6V p-p range.
>> Drive that into a 5V compatible CMOS
Bob
With a 1V p-p sort of output, a simple matching network will get you into the 4
to 6V p-p range.
Drive that into a 5V compatible CMOS gate and move on …. If you have a super
hot output, put
a 3 db pad on it.
Bob
> On Jan 19, 2018, at 5:40 PM, Tom Van Baak wrote:
>
>> Tom
>> What's the
Hi
The antenna has a measured / documented pattern (amplitude and more importantly
phase). If you have it pointed in a known direction, that information can be
used when
post processing carrier phase information. If you are trying to get to mm /
picosecond
levels on an multi hour L1/L2 dataset
Hi
Since this *is* an L1 / L2 antenna, there are a lot of things you might be
doing with it.
If indeed dual frequency GPS is part of the intended use, the survey oriented
gear
will be slightly happier if the “right” corner faces north. It only really
counts in that sort
of L1 / L2 data reducti
Hi
It is very much a 12V antenna. It also is a “50 db gain” antenna as well.
Most of the timing gear is looking for 20 to 30 db less gain than that in
an antenna. The good news is that you can run a really big splitter after
one to drive lots of stuff. The bad news is that you may still need att
Hi
They always had a pretty lean operation and some unique approaches as part of
their business plan. That said, they do seem to be a going concern.
Bob
> On Jan 19, 2018, at 3:54 AM, John C. Westmoreland, P.E.
> wrote:
>
> Hello All,
>
> Just wondering - has anyone made any recent purchase
Hi
Back a number of years ago I did a number of them. The results
vary a bit between units and depending on the quality of the antenna.
No idea if I can dig that data back up again or not.
Bob
> On Jan 17, 2018, at 9:57 AM, ew via time-nuts wrote:
>
> Has any one done a 24 hour plot of the
Hi
If the time offset gets to the point that it bothers the measurement, you
likely are
running to low a difference frequency. It is quite possible (though not easy)
to get
low parts in 10^-13 running an offset of 8 or 9 Hz at 10 MHz.
If you are running very precise signals, then line stret
Hi
You have to measure two different outputs to do what you describe. The PPS
measurements
are limited to > 1 x10^-10 with most counters at tau = 1 second and 2x10^-11
with some exotic
models. The mixer based stuff can get around three orders of magnitude past
that at the same
tau. Since a pra
Hi
I would second Paul’s input. Is the unit actually working at the moment? Some
of the circuits in these gizmos *do* run pretty hot in normal operation.
If there is a problem with that device, before I paid $67 for the replacement
part
(or anything close to that) I probably would convert it al
Hi
The normal TBolt supplies 5V to the antenna. There *are* some 3.3V only antennas
out there. You could blow one up with a TBolt. There are also survey oriented
receivers (and antennas) that work at 12V. Most 5V (but not all) antennas will
fry
if hooked to a 12V receiver.
Current wise, you pr
Hi
Depending on the noise floor of the phase detector (which probably is not super
duper), even the noise *inside* the PLL bandwidth may not be all that great.
Bob
> On Jan 8, 2018, at 2:23 PM, Bruce Griffiths
> wrote:
>
> Yes, but the PN noise (outside the PLL bandwidth) will be much higher
Hi
> On Jan 7, 2018, at 12:55 PM, Jerry Hancock wrote:
>
> As far as lazy, I will check my equipment.
>
> When the others that replied using the term “lock” or “locked”, what do you
> mean by that? That for instance, the external reference is multiplied up
> directly to the internal frequen
Hi
> On Jan 7, 2018, at 12:26 PM, jimlux wrote:
>
> On 1/7/18 8:05 AM, Arnold Tibus wrote:
>> Am 07.01.2018 um 16:33 schrieb jimlux:
>>> On 1/6/18 6:12 PM, Dana Whitlow wrote:
One point about oscillator design I've not yet seen mentioned is this: the
limiter
must not degrade the r
Hi
> On Jan 7, 2018, at 10:21 AM, Jerry Hancock wrote:
>
> I’m being a little lazy as I can check the schematics, but in the general
> case, do HP counters, frequency generators, etc, switch to the external
> reference when one is available or discipline the internal oscillator?
No, not if
h Gwinn wrote:
>>>> --
>>>>
>>>> Message: 2
>>>> Date: Sat, 6 Jan 2018 09:19:31 -0500
>>>> From: Bob kb8tq
>>>> To: Discussion of precise time and frequency measurement
>>>>
>>
t;> I've long wondered if a very slow AGC might avoid the nonlinear mechanisms
>> issue except, of course, for things happening within the AGC loop's
>> bandwidth.
>> Is anybody reading this aware of what the truth really is?
>>
>> Dana
>>
>
Hi
> On Jan 6, 2018, at 4:31 PM, Joseph Gwinn wrote:
>
>> --
>>
>> Message: 2
>> Date: Sat, 6 Jan 2018 09:19:31 -0500
>> From: Bob kb8tq
>> To: Discussion of precise time and frequency measurement
>>
>
esign actually works.
>
> The modified Leeson model starts to approach the actual design.
>
> Cheers,
> Magnus
>
> On 01/06/2018 03:19 PM, Bob kb8tq wrote:
>> Hi
>>
>> The key point missing is the fact that any real oscillator must have a
>> limiter
>
Hi
The key point missing is the fact that any real oscillator must have a limiter
in the loop. Otherwise it will “create one” by going over the max output of
this or
that amplifier. To the degree that the limiter has issues (limits poorly) you
will get
AM noise.
On a practical basis, loop Q is
ote:
>
> But what I'm wondering, because this is important to the discussion, is the
> tone at a frequency encompassed on both sides by the noise band? Or
> is the tone outside the noise band?
>
> Dana
>
>
> On Fri, Jan 5, 2018 at 1:35 PM, Bob kb8tq wrote:
>
Whitlow wrote:
>
> Is this an audio tone, summed with audio noise whose spectrum surrounds
> that of the tone?
>
> Dana
>
>
> On Fri, Jan 5, 2018 at 9:56 AM, Bob kb8tq wrote:
>
>> Hi
>>
>> If I pass both a sine wave tone and a pile of audio noise
Hi
If I pass both a sine wave tone and a pile of audio noise through a perfectly
linear circuit, I get no AM or PM noise sidebands on the signal. The only way
they combine is if the circuit is non-linear. There are a lot of ways to model
this non-linearity. The “old school” approach is with a po
Hi
Your typical junk PC has a number of the connectors you need in it
The wire gauge is normally “good enough” to allow them to be dropped
right into the job of powering a TBolt. PC’s are only one of many devices
that use the same stuff …. check your junk box.
Bob
> On Jan 4, 2018, at 11:09 A
Hi
I would second the previous comment on the 113. Every time I have seen one it
has been a really noisy device. Certainly *not* what you would want in anything
described as a “quiet lab”. Since it’s full of gears (like a Teletype) proper
lubrication
and cleaning are going to be part of the proc
Hi
Just as with PM noise, AM noise is a “that depends” sort of thing. The first
dependency is on your test gear. If the AM noise was well below the PM
noise, would you be able to measure it? Equally, if you are doing something
like a diode detector - can it measure AM below XXX dbc? If the dete
Hi
If the code also *is* part of the deal (or becomes part of the deal) I would
suggest that there
are a series of papers in the “to be written” category about how it does what
it does. I have
no idea what the code looks like so this is in no way a knock. It’s a big
program with a lot of
resea
Hi
The 70 or 100K resistors are in there because they are a dirt cheap way to
isolate
the RF on the diode from the DC control signal. If by some strange error, the
diode
actually *has* leakage near its ratings, they could be an issue. Real world
diodes
don’t ever seem to have measurable leakage
Hi
With these little OCXO’s you likely will move them 0.1 ppb simply walking
past the bench. If they have a total of 0.25 ppm of trim, a 25 turn pot will
get
you 1 ppb per turn. Setting these pots to 1/10 turn is not all that crazy.
Yes, there are a bunch of assumptions made there and your se
Hi
The nice thing is that the footprint on the Pulse Puppy is pretty generic.
There are a lot of OCXO’s on eBay that will fit the pattern on the board.
When you get into the more exotic parts, the footprints (and functions)
don’t tend to be as standardized.
The small package OCXO’s will always
Hi
The other issue with putting in an amp is noise. You really do not want to feed
a bunch of added “stuff” into the FM modulation port on the oscillator. You get
some thermal noise from the pot, so it is never zero. How close you need to get
to zero - who knows? When the part was tested to see if
Hi
There’s a lot of debate out there about that.
When used as a variable resistor (two terminal device) there is no doubt that a
sereis resistor can help. When used as a voltage divider (three terminal
device)
the claim by the pot manufacturing OCXO companies is that you are better with
no add
Hi
Looks neat !!!
It is a pretty good bet that everything you see in the ADEV plot is a function
of the
specific OCXO you put on the board. Put another way, the. board’s ADEV is way
better than the ADEV of the OCXO. It’s a very safe bet that everything past 2
seconds
or is the OCXO.
Bob
> O
Hi
What is the Time Nut goal here? Are we after the carrier frequency or after the
modulation on the signal?
Bob
> On Dec 23, 2017, at 10:46 AM, Stephan Sandenbergh
> wrote:
>
> Oops, I noted a sign error in the previous diagram. The attached seems
> better...
>
> On Sat, Dec 23, 2017 at 4:4
Hi
Assuming you are trying to extract timing from the signal (time ticks on WWVB),
the
downconversion really does not matter. The ADC samples are what will “tag” your
time data. If you are trying to extract frequency from the signal (you are
after the center
frequency of WWVB) then both the of
Hi
Yes, this *is* a bit off topic. Sorry about that … I’m sure it’ll never / ever
happen
again :) …. ummm …. today ….
The voltage that supply feeds are set to is as much a public relations issue as
a
technical one. People would routinely complain “the lights are to dim”. Voltage
gets bumped u
still a good $100 investment.
>
>
>
> On Mon, Dec 18, 2017 at 11:43 AM, Bob kb8tq wrote:
>
>> Hi
>>
>> The 53132 is the older version of the 53230 counter. It’s been out of
>> production
>> and past "end of life" support for quite a while now.
Hi
The 53132 is the older version of the 53230 counter. It’s been out of
production
and past "end of life" support for quite a while now. It’s main issue
measurement
wise is a group of issues that make it less sensitive (lower resolution) than
one
might think right at 10 MHz and to a lesser
Hi
If you go back a ways in the archives, there is a *lot* of information about how
to run these beasts. There also are links to the software and command sets
for the devices.
Bob
> On Dec 17, 2017, at 5:01 PM, Patrick Murphy wrote:
>
> I have recently acquired a used Lucent RFTGm-II-Rb and XO
Hi
> On Dec 17, 2017, at 6:50 PM, Magnus Danielson
> wrote:
>
> Hi,
>
> On 12/17/2017 03:09 PM, Mattia Rizzi wrote:
>>> you demand ergodicity, you cannot have 1/f. You can have only one or the
>> other. Not both. And if you choose ergodicity, you will not faithfully
>> model a clock.
>> I am
on period is 486 hours.
>>
>>
>>
>>
>> On 2017-12-14 23:13, Jim Harman wrote:
>>> On Thu, Dec 14, 2017 at 10:53 PM, Bob kb8tq wrote:
>>>
>>>>
>>>>
>>>> Of course this *assumes* an electronic approach. Given that i
Hi
My guess is that the “best design” would likely do a sample at some specific
time of day.
Just when would depend a bit on your local grid and how it is fed and loaded.
There are
definitely “it’s 6 PM and everybody just got home” issues with power line
phase.
Next question wold be how long
Hi
I’m having a little trouble spotting the 9836 in AD’s current lineup of DDS
chips. The
stuff below is thus a bit generic.
My guess is that you will have a hard time finding a canned solution. There are
a
bunch of registers on your typical DDS part. The what to stuff where tends to
be prett
Hi
I would bet that the design changed a bit since 1983. That is a “long time ago”
in terms of OCXO design. Since we are picking up this stuff surplus or pulling
it out of older gear, who knows what era this or that example might come from.
Bob
> On Dec 12, 2017, at 12:32 PM, Ed Palmer wrote
Hi
One of the basic issues with a quartz resonator is that it is sensitive to
barometric pressure.
Some are more sensitive than others, but there always is some effect. Various
techniques
get used to isolate the resonator. Solder sealing (or welding) the package
closed is one of
them. The in
Hi
Just as there are Time Nuts, there are Tide Nuts (I suppose it’s capitalized
…).
There is a a lot of data out there on just what sort of solid tides one might
see at this or that point.
Bob
> On Dec 10, 2017, at 7:29 AM, Azelio Boriani wrote:
>
> Is that a Trimble Thunderbolt? Is there
Hi
If the frequency sensitivity is 1x10^-13 / G you don’t need a lot of precision
in your measurement of G. The same issues apply to things like magnetic
field and the rest.
Bob
> On Dec 9, 2017, at 4:02 PM, Chris Caudle wrote:
>
> On Sat, December 9, 2017 2:39 pm, Magnus Danielson wrote:
>>
Hi
I suspect that at the practical level, you define standard atmospheric
pressure, standard
gravity, standard magnetic field ….. and on down the list. At some point “sea
level” becomes
a redundant expression.
Bob
> On Dec 9, 2017, at 2:14 PM, Mark Sims wrote:
>
> In the standards definitio
Hi
If you dig back into the various papers on the subject (and the proceedings
that log the post paper questions) the issue of “can we trust the
implementation?”
does indeed come up. It’s come up for at least the last 50 years that I’m aware
of.
The basic argument runs that for fundamental stand
Hi
It might be, if it is then an upper turn in the 80C range is not all that crazy.
Bob
> On Dec 8, 2017, at 4:24 PM, Angus wrote:
>
>
> That near the end of the temperature range the direction could also
> give a good indication - assuming that there is only one problem...
>
> I think the 8
uency adjust turned to maximum. I'm a rank amateur at this but the
> circuit diagram looks like a series-resonant (Pierce) oscillator. Looks
> like I need to replace one of the capacitors inside the oven with a smaller
> value.
>
>
> On Fri, Dec 8, 2017 at 12:40 PM Bob kb8t
Hi
One basic question - Is the frequency high or low?
Assuming it’s an SC and on the lower turn, frequency low is possible
with an off temperature oven. Frequency high is unlikely unless it’s *way*
off temperature. How far off turn gives you how much delta F depends on
the inflection temperatur
here is always
> something that drifts, somewhat.
>
> Cheers,
> Magnus
>
> On 12/08/2017 06:27 PM, Tom Knox wrote:
>> Hi All;
>>
>> Is the "Aging" generally related to the quartz, or other components?
>>
>> Happy-Merry;
>>
&
t; arrangement.
>> That sounds ugly.
>> Regards
>> Paul
>> WB8TSL
>>
>> On Fri, Dec 8, 2017 at 10:17 AM, Bob kb8tq wrote:
>>
>>> Hi
>>>
>>> It is quite possible that nothing is actually broken and that the
> crystal
>
uick look at the spec sheet.
>> It appears coarse adjustment is an option M and would actually be a pot.
>> That speaks to another tuning diode for coarse? Or a pot on pot arrangement.
>> That sounds ugly.
>> Regards
>> Paul
>> WB8TSL
>> On Fri, Dec 8, 2017
an option M and would actually be a pot.
>>> That speaks to another tuning diode for coarse? Or a pot on pot
>>> arrangement.
>>> That sounds ugly.
>>> Regards
>>> Paul
>>> WB8TSL
>>>
>>> On Fri, Dec 8, 2017 at 10:17 AM, Bob kb8tq
Hi
It is quite possible that nothing is actually broken and that the crystal has
simply drifted
outside the tuning range. It should be pretty easy to spot the coarse tuning
device once
the package is open. I would bet you will find a selected capacitor across the
coarse tune or in
series with
Hi
If you happen to pick 5 or 10 MHz as your target frequency, all sorts of
interesting
things come into play. The first is that any 5 or 10 MHz local standard
distribution
may well get into your receiver. That can create all sorts of odd effects as
the signal
fades. Next is that you aren’t j
Hi
I agree that your TBolt likely had some sort of issue. That probably needs to
be
tracked down independent of any other “quest”. First recommendation would be
to run the filter tune stuff in LH.
Accuracy, stability, and repeatability are all different things. They do bump
into
each other fr
Hi
A lot depends on just how this or that was implemented. The bottom line is
still that
ionosphere issues will give you a “couple of milliseconds” sort of ill defined
variation.
If your RF chain is below 10 MS (which it likely is) is a bigger delay, but not
a bigger
variation.
Bob
> On De
Hi
Back a while ago EG&G decided they needed a new name. The connection of the
company name to various pieces of history was believed to be an issue. Back then
they were actively buying up various companies. When they bought Perkin Elmer,
they decided to use that name for the new company. I used
; Leo
>
> From: Bob kb8tq
>> GPS extracts time and location by locking on to various codes in the
>> transmissions.
> One of them happens to run at about a 1 KHz clock rate. A slip on that part
> of the
> process gives you a (modulo) 1 ms clock jump. Certain types of
Hi
GPS extracts time and location by locking on to various codes in the
transmissions.
One of them happens to run at about a 1 KHz clock rate. A slip on that part of
the
process gives you a (modulo) 1 ms clock jump. Certain types of interference may
“help” the receiver make these sorts of mist
:10 PM, Attila Kinali wrote:
>
> On Thu, 30 Nov 2017 09:39:59 -0500
> Bob kb8tq wrote:
>
>> That last decade ( 0.01 Hz period to 0.001 Hz)
>
> What puzzles me here is, the reason why someone would care
> about sub-1Hz frequencies in a telephone system? IIRC POTS
>
Hi
> On Nov 30, 2017, at 11:10 AM, Magnus Danielson
> wrote:
>
>
>
> On 11/30/2017 03:40 PM, Attila Kinali wrote:
>> On Thu, 30 Nov 2017 12:44:13 +0100
>> Mattia Rizzi wrote:
>>> Let me emphasize your sentence: "you will have a statistically significant
>>> number of samples of *one* realiz
frequency and the nonsense db fraction in it
….
Bob
> On Nov 30, 2017, at 3:29 AM, Poul-Henning Kamp wrote:
>
>
> In message <42a2f881-1631-402c-8ed6-2c863f6fe...@n1k.org>, Bob kb8tq writes:
>
>>>> Needless to say *demonstrating* this 0.001 db sort of
.
Bob
> On Nov 29, 2017, at 9:08 PM, Tim Shoppa wrote:
>
> At that low a frequency aren’t you actually testing the temperature and time
> stability of the gain controlling components?
>
> Tim N3QE
>
>> On Nov 29, 2017, at 9:04 PM, jimlux wrote:
>>
>>
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