Hi
Part of the typical receiving process is reducing the bandwidth. With a smaller
bandwidth you can get away with a lower sample rate without loosing useful
information. The normal approach is to drop the sample rate as you move through
the system.
When you drop the sample rate (say 4:1)
Hi
On some counters, if both inputs arrive at exactly the same time, they get very
confused. The normal approach is to offset one by a few hundred ns or so. The
exact offset is fairly non-critical. It’s real value depends entirely on the
amount of drift you expect to see over the time period
Hi
When you do any of these delay line based gizmos, you get some very strange
outputs. Flip flops go metastable, edges don’t quite arrive in the right
sequence. If all you do is look for solid ones or solid zeros you don’t get a
lot of data. Counting the ones and counting zeros is another
Hi
From what I’ve seen, if you are after a large wall clock with mechanical hands
on it, you already have the top of the line. There are others out there. The
ones I’ve seen or tried are no better than what you already have. Many of them
are worse...
Yes, that’s sad. They are designed to hit
, it
shouldn't be a big step to use it as a basis for frequency measurement.
Bob
On Sunday, February 23, 2014 1:21 PM, Bob Camp li...@rtty.us wrote:
Hi
From what I’ve seen, if you are after a large wall clock with mechanical
hands on it, you already have the top of the line
Hi
Very cool. Glad I kept that stack of 5370’s….
Bob
On Feb 23, 2014, at 10:56 PM, John Seamons j...@jks.com wrote:
Please excuse this commercial announcement (although it is a near-zero profit
endeavor).
I am now accepting general orders for the hp 5370 processor replacement board.
More
Hi
Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If that’s
all you need to deal with (you correct out the crystal offset one way or the
other) then:
At 1 day you have 11.5 ppm accuracy. Roughly a 100 Hz beat note with WWV at 10
MHz.
At 10 days you have 1.15 ppm.
Hi
One of the more common explanations for the 18 GHz “upper limit” is that the
broad water vapor absorption peak at about 23 GHz made systems less practical
as you went up from 18. I suspect the same water issues make certain types of
parts more difficult to fabricate.
Bob
On Feb 26, 2014,
Hi
Not having one here, about all I can guess is that there are 360 degrees in a
cycle. If it’s going through 360 degrees in 10 seconds it’s 0.1 Hz off at what
ever point it’s comparing. If it takes 100 seconds that’s 0.01 Hz.
Yes I get this pesky decimal point stuff wrong from time to time
Hi
I realize this is a bit off the main topic of … but here goes:
Is there any performance data on how the card does with a 5370A and / or a
5370B compared to the original CPU on the exact same box? Put another way -
does the counter get better or worse with the new card? I realize that an A
-4790-9d20-e4dac1f60...@rtty.us, Bob Camp writes:
Is there any performance data on how the card does with a 5370A and / or a
5370B compared to the original CPU on the exact same box? Put another way -
does the counter get better or worse with the new card? I realize that an
A will do some things
interesting with a digital
filter on the PLL ...
Bob
On Feb 28, 2014, at 8:18 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message 87caf1a2-d281-4331-b019-b01b06f11...@rtty.us, Bob Camp writes:
To me the next layer here is to see if the basic accuracy of the device
can be improved
Hi
There is a fairly involved alignment process for the multiplier chain. My
*guess* is that small tweaks to the alignment could impact these timing spikes.
Sub harmonics tend to produce multiple zero crossings that show up as periodic
jitter in the output. The offset input peaks may be a
Hi
I am not at all sure that a mid setting on the VCXO is really the right thing
to do. I’ve seen quite a few Rb’s from a number of manufacturers. They all seem
to set up the sweep process so it sweeps fairly far low but not very far high.
There are multiple quantum state transitions possible
mag...@rubidium.dyndns.org wrote:
Hi Bob,
On 01/03/14 16:55, Bob Camp wrote:
Hi
I am not at all sure that a mid setting on the VCXO is really the right
thing to do.
It's not really the right thing to do. You should trim it to one end so that
further continuous drift makes trimming time
Hi
They run an NCO (drop / add pulses) to generate the PPS off of the TCXO. The
amount of adjustment is a function of the solution they derive from the GPS
messages. In some cases they do a solution, and correct the *next* edge to that
solution. In other chip sets the solution and the edge
be spotty, so I've switched to
standard internet net time source).
On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote:
Hi
Ok, so 0.1 second at the sync point is indeed a reasonable estimate. If
that's all you need to deal with (you correct out the crystal offset one
way
.html
As I recall, it was under $100, quite nicely styled, and is sitting here on
my desk. (Reception on the East Coast can be spotty, so I've switched to
standard internet net time source).
On Mon, Feb 24, 2014 at 7:44 AM, Bob Camp li...@rtty.us wrote:
Hi
Ok, so 0.1 second
Hi
When you say “adjust crystals close” do you mean:
1) Grinding / plating crystal blanks? (as in fabricating crystals from scratch)
2) Setting uncompensated crystal oscillators on frequency? (as in some radios)
3) Calibrating the OCXO that is the master reference for an instrument?
That all
Hi
It’s a 10 MHz box from the look of it. Everything looks like it’s in the right
place and nothing is broken. It should be good for at least 100 mw into it. It
will have at least 9 db of loss just from the power splitting. If you want 7
dbm out of it, you will need at least 16 dbm into it.
Hi
Assuming you are after a reference at 10 ppb accuracy:
10 ppb would be a 10 second beat note on WWV at 10 MHz. (I *hope* I got the
decimal point right that time).
Fire up your radio and start listening to the various frequencies. You want a
time when it’s crystal clear with absolutely no
temperature
performance is not required, the temp run step may be left out.
On Sunday, March 2, 2014 7:41 AM, Bob Camp li...@rtty.us wrote:
Hi
Assuming you are after a reference at 10 ppb accuracy:
10 ppb would be a 10 second beat note on WWV at 10 MHz. (I *hope* I got the
decimal
over a limited range it's linear. The problem of course is calibration.
Again, how does one calibrate those 3 MHz ovenized units?
Bob
On Sunday, March 2, 2014 7:41 AM, Bob Camp li...@rtty.us wrote:
Hi
Assuming you are after a reference at 10 ppb accuracy:
10 ppb would be a 10 second
Hi
Depending on which auction you find and what they include you may indeed have
some other bits and pieces to dig up as well. The prices run in cycles, so you
will always pay a bit more if you “want it right now” than if you are willing
to sit back and shop for a few months.
Bob
On Mar 2,
Hi
These days, you can get some *very* low cost crystals. They sell by the pound
rather than by the piece. The tolerance as delivered may be 0.1% for
temperature plus calibration. Aging is likely to be “who knows”. The
temperature characteristic could be a third order curve. More likely it’s a
Hi
If you look at the wiring to the input connector and the output connectors,
that’s not the way you wire VHF or UHF gear. The same is true for the “ground
through case” on those connectors.
Bob
On Mar 2, 2014, at 12:54 PM, Tom Miller tmiller11...@verizon.net wrote:
It looks like the
HI
If that is what you currently have for references, then you probably need a
“lab standard” to drive things. Having one reference for all the gear makes
things *much* easier. You don’t have to mess with a lot of “which one’s right
today” sort of decisions.
That would make the GPSDO pretty
Hi
As long as your resistor keeps the temperature to within a micro degree it will
do pretty well.
Bob
On Mar 2, 2014, at 2:09 PM, Chris Albertson albertson.ch...@gmail.com wrote:
Junk crystals are good thermometers. Ballpark is 1 ppm/degree-C
So does this mean I can epoxy a sandstone
Hi
The gotcha is that there are second order temperature effects. If you are going
to run the crystal very far off turn, you need to keep it more stable than you
might think.
Bob
On Mar 2, 2014, at 3:40 PM, Jim Lux jim...@earthlink.net wrote:
On 3/2/14 12:21 PM, Bob Camp wrote:
Hi
HI
On Mar 2, 2014, at 4:00 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
On 02/03/14 21:45, Bob Camp wrote:
Hi
The gotcha is that there are second order temperature effects. If you are
going to run the crystal very far off turn, you need to keep it more stable
than you might
On Mar 2, 2014, at 5:29 PM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
Hi Bob,
On 02/03/14 23:16, Bob Camp wrote:
HI
On Mar 2, 2014, at 4:00 PM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
On 02/03/14 21:45, Bob Camp wrote:
Hi
The gotcha is that there are second
Hi
Do you have any idea how “clean” your 200 MHz signal is? The manual suggests
getting it to -65 dbc for subs using a spectrum analyzer. That’s pretty far
down. I seem to recall the adjustment process being a bit tedious (lots of back
and forth).
Bob
On Mar 2, 2014, at 5:29 PM,
Hi
I believe the paper was by Stan Shadowski. I’m *certain* I’ve mis-spelled his
last name, which is indeed a very poor move on my part. I would not be
surprised if there are several co-authors.
I don’t have the UFC indexes here at home so I have no quick way to look it up.
Bob
On Mar 2,
Hi
The countdown clock on the Oscars looks like it’s about 11 seconds off here in
PA. Time is part of a *lot* of things ….
Bob
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
Hi
The simple approach is to use an op amp, a thermistor, and a couple of
resistors. No need for anything digital. You can easily get all the gain
possible (before oscillation) out of a very simple circuit.
The net result will be about a 1C stability when you run it over temperature
(say 0
3, 2014, at 2:26 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message e7a494f6-78f1-4568-8bd3-d94a32deb...@rtty.us, Bob Camp writes:
Do you have any idea how 'clean' your 200 MHz signal is? The manual
suggests getting it to -65 dbc for subs using a spectrum analyzer. That's
pretty far
Hi
If you are measuring temperature in a room who’s temperature does not change,
then yes you can hold 0.1 C. That of course is based on the “room does
not change temperature” and that equates to absolutely no change at all.
The only rational way to discus temperature stability is as a
it back with a bit of heat.
I will have to be kept at a temperer above the hottest it will ever
get inside the house, maybe 100F.
On Mon, Mar 3, 2014 at 3:18 PM, Bob Camp li...@rtty.us wrote:
Hi
If you are measuring temperature in a room who's temperature does not
change, then yes you can hold
Hi
So I can use the scrap (zero value) 5 MHz 3rd OT HC-40 package SC’s that are
sitting in a pile in the basement right ?
Bob
On Mar 3, 2014, at 8:47 PM, Chris Albertson albertson.ch...@gmail.com wrote:
On Mon, Mar 3, 2014 at 4:51 PM, Charles Steinmetz csteinm...@yandex.com
wrote:
What
Hi
A traveling clock process is still the only way to fully validate a local time
setup. The NIST modems can get close, but a clock (second opinion) is the only
way to be sure.
Bob
On Mar 3, 2014, at 9:09 PM, Tom Van Baak t...@leapsecond.com wrote:
Hi Jim,
Nice video. I had not see that
Hi
One of the early relativity confirmation experiments was done with very similar
clocks before that film clip was made. There were a number of corrections made
as part of the trip. One of them was to re-confirm the traveling Cs once it got
back to it’s starting point. You only could “use”
Hi
Also consider that the “trip” was not very quick. They were a: spend day or
three here, go there (day of travel), spend several days someplace else, move
on to next location. Eventually you returned the clock to it’s starting point.
The “trip” was only good to something related to the drift
Hi
Be careful of what you wish for.
One way to “eliminate” the hanging bridge is to have the oscillator exactly on
frequency. That sounds fine. The problem is that you are always in the middle
of a bridge. The other way is to put the oscillator well off frequency. That
way you have lots of
, Mike M timen...@binsamp.e4ward.com wrote:
Bob Camp wrote:
Hi
Be careful of what you wish for.
One way to eliminate the hanging bridge is to have the oscillator
exactly on frequency. That sounds fine. The problem is that you
are always in the middle of a bridge.
Bob
That's fine
- Original Message -
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Wednesday, March 05, 2014 3:03 PM
Subject: Re: [time-nuts] Another atomic clock question
Hi
If you are going to decode and use the sawtooth
- Original Message -
From: Bob Camp li...@rtty.us
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Wednesday, March 05, 2014 3:03 PM
Subject: Re: [time-nuts] Another atomic clock question
Hi
If you are going to decode and use the sawtooth data out
Hi
The sawtooth correction on a good GPS will go down to a few hundred ps over a
thirty or so ns range. If you are going to correct, you need a chip that is
accurate to 100 ps over a 30 ns ( 300 tap) range. That’s a tough part to
find. Next you need to worry about jitter in the delay line ….
the implementation of the sawtooth error correction
severely degrades the performance of the system. There could be many
reasons, which is why it is important to nail down as many of the
error sources as possible.
/tvb
- Original Message -
From: Bob Camp li...@rtty.us
To: Discussion
Hi
You can put the LEA-5T or the LEA-6T into a mode where they put out the
sawtooth information on auto pilot. Once you get it set up (which you do each
time you boot) it just keeps going. You must have the T version of the modules
to get the sawtooth out of them.
Bob
On Mar 7, 2014, at 4:10
Hi
With a “real” 12 to 13 bit ADC and a 200 ns TDC pulse you would ideally get
200 / 4096 as your LSB. Nothing like this is ever perfect, so you probably
aren’t going to get 50 ps. You probably will be below 100 ps. That’s plenty
good enough to make sawtooth correction useful.
Bob
On
Hi
On the 4’s and 5’s you only got a pulse + correction with the T model.
Bob
On Mar 7, 2014, at 8:06 PM, Paul tic-...@bodosom.net wrote:
On Fri, Mar 7, 2014 at 5:45 PM, Bob Camp li...@rtty.us wrote:
You must have the T version of the modules to get the sawtooth out of them.
Per
Hi
Do you routinely do arc welding while waiting for an ADEV plot to finish :)… (I
drink beer, but not everybody is into that …)
You might consider trying a passive splitter on one of the outputs of the
GPSDO. There aren’t many ways they will mess up a signal other than by dropping
it’s
the 10MHz for frequency measurement (reference and
input).
Lower level is a concern, since it increases phase jitter.
Volker
Am 09.03.2014 23:32, schrieb Bob Camp:
Hi
Do you routinely do arc welding while waiting for an ADEV plot to finish :)…
(I drink beer, but not everybody
Hi
If you watch long enough and know the clock frequency, you will find
corrections over the entire period of the clock. In most modules that shows up
as a +/- 1/2 clock period correction.
Bob
On Mar 10, 2014, at 2:03 AM, Hal Murray hmur...@megapathdsl.net wrote:
albertson.ch...@gmail.com
network is a useful, manageable gadget.
Volker
Bob Camp li...@rtty.us hat am 10. März 2014 um 01:47 geschrieben:
Hi
So far, I have not found the 3db lost in a a passive splitter to be a problem
with anything I have played with. With proper termination , they seem to be a
good thing
Hi
Either grab a math pack (there are several for the PIC) or go to C.
Timing at the Time Nuts level is about precision. We need *lots* of digits past
the binary point :)
Bob
On Mar 13, 2014, at 7:19 PM, Bob Stewart b...@evoria.net wrote:
OK, gotcha. But, this is in assembler, and
Hi
If you use multiple regulators for the same supply and they don’t come up at
the same time, odd things can happen. On some chips those odd things include
smoke. In most cases where it fails, the more common effect is the internal
reset does not work properly and you can’t talk to the chip.
Hi
The real answer is always “that depends”.
1) How much does the sensitivity of your OCXO change with a change in EFC?
1.4:1, 2:1, 4:1 …. (slope sensitivity not % linearity)
2) How quiet is your DAC compared to your OCXO?
3) How quiet is your reference compared to your OCXO?
4) How much
find that
your 2 ppm reference has 40 ppm of hysteresis, including that in the model
might move up your list a bit….
Bob
On Mar 23, 2014, at 10:02 AM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
On 23/03/14 14:02, Bob Camp wrote:
Hi
The real answer is always “that depends”.
1
Hi
Unless you can include all the second and third order effects in your model,
there will still be a lot to “learn” as you build your gizmo. Computing power
is still impacted by garbage in / garbage out.
Bob
On Mar 23, 2014, at 12:07 PM, Don Latham d...@montana.com wrote:
I agree.. Had a
Hi
You can (and many do) run through a list of servers with an NTP client and see
what you get. It’s a bit of work, but you only do it once.
———
I suspect that what NIST is looking for is somebody in the cloud business
(Amazon, Google, Microsoft, IBM) to step up and mention that they have
Hi
If you have a source of “noise” that is not in your model *and* it’s
significant, then your model will not predict the outcome. That’s true if it’s
in or if it’s outside the loop bandwidth.
Bob
On Mar 23, 2014, at 2:27 PM, Hal Murray hmur...@megapathdsl.net wrote:
4) How much do the DAC,
Hi
While you would *think* that LTE and PCS signals would be locked to “something
good”, that’s not always the case. If you decide to use something like this for
timing, it’s best to check things out carefully. Symmetricom learned this the
hard way on one of their boxes ….
Bob
On Mar 23,
Hi
…. and GPS has cyclic issues on a 24 / 48 hour basis ….
Bob
On Mar 23, 2014, at 8:58 PM, Tom Van Baak (lab) t...@leapsecond.com wrote:
Rule of thumb:
- really good OCXO have frequency drift rates of 1e-10 to 1e-11/day
- common Rb have frequency drift rates on the order of 1e-11/month
-
Hi
Which R’s and C’s did you buy? There are a *lot* of different types and they
each have their issues. A very common issue is - “they came from the store”.
Any ability to trace them back to a manufacturer and a process has been lost.
Bob
On Mar 24, 2014, at 2:29 AM, Hal Murray
Hi
There is a lot of math in a GPS receiver. In a “typical” nav receiver, time is
not a priority. The code may well be optimized to “shove” all the error into
time rather than position. They also may not have spend much effort debugging
the time related code ….
Bob
On Mar 23, 2014, at 11:08
Hi
Exactly correct, the sawtooth corrects for the hanging bridges.
Since that’s what it does, sawtooth correction error is not totally random.
Hanging bridges are not totally random. One looks like the other. Sawtooth
correction errors can / will have hanging bridges in them.
If you are
-834a-4733-bed8-fcfec0ccb...@rtty.us, Bob Camp writes:
I should add here, that you _can_ do a little bit better than the
sawtooth correction.
We know, or at least assume, that the GPS's internal clock is step-less
and slowly changing, so if you put a predictive filter on this stuff,
it can
Hi
If you are building a GPSDO, then the 1 pps out of the GPSDO should be much
better than the pps out of the GPS. Making that happen is part of the control
optimization.
Bob
On Mar 25, 2014, at 7:46 PM, ewkeh...@aol.com wrote:
Yes if you want to use it only in a GPSDO and it is being done
Hi
There have been multiple posts about analog TDC’s of various designs that get
you into the sub 100 ps range without costing very much money. I believe the
cheapest posted so far adds 50 cents to a basic PIC based design.
Bob
On Mar 25, 2014, at 7:38 PM, Jim Miller j...@jtmiller.com
Hi
Take a look at the PIC-TIC stuff. They have the HP circuit in the middle of it.
Bob Stewart posted a circuit with a pair of tri-state gates in it within the
last month or so.
They all pretty much:
1) Measure the “coarse time” with a counter Today that’s just about always a
counter in an
Hi
Having done this - it gets really boring to sit there for 10,000 seconds and
collect data. Best to automate the process.
In reality you want to run three groups of 10,000 samples and see how they
relate to each other. With some approaches you can find some disturbing things
going on.
Bob
?
Just want to make sure
I am not missing some other meaning.
Thanks, learning a lot from reading this group!
Matt Martin
On Wed, 3/26/14, Bob Camp li...@rtty.us wrote:
Subject: Re: [time-nuts] Hanging bridge question
To: Discussion
Hi
The quick / dirty / easy way for any of the NTP stuff with a GPSDO is to simply
run the PPS in. PPS into serial is one way, pps into a GPIO is another way.
Bob
On Mar 26, 2014, at 5:51 PM, Henry Hallam he...@pericynthion.org wrote:
Hi Gabs,
I have a Z3805A and a Beaglebone, and would
Hi
64 bit int’s with 128 bit intermediate results can do a pretty good job for
most of this.
Bob
On Mar 26, 2014, at 6:47 PM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message 514d.5090...@rubidium.dyndns.org, Magnus Danielson writes:
Did some home-work on third-degree PLL
Hi
With a GPIO pulse width should not be an issue. With RS-232 you might have
needed a pulse stretcher.
Bob
On Mar 26, 2014, at 7:18 PM, Brian Lloyd br...@lloyd.com wrote:
On Wed, Mar 26, 2014 at 5:05 PM, Bob Camp li...@rtty.us wrote:
Hi
The quick / dirty / easy way for any of the NTP
Hi
Crystals are susceptible to vibration. That’s pretty well documented. They have
resonances in the mount structure. They have a 2G tip sensitivity.
Audio when it “impacts” an oscillator induces vibration. If your noise source
is a rocket engine, then the vibration is “non trivial”. You do
Hi
The problem is that it can / might / could / will create a “dc bias” in the
noise. When you filter it, you get a bump rather than zero. If your GPSDO has a
47 ns wide sawtooth, that could be a pretty big bump. There’s no way to know if
the bridge is seconds, minutes, or hours wide. You can
Hi
Since the output of your GPS (short term and long term) is likely much better
than your ability to measure (using your setup), why not just drive the clock
with the GPS? You would use far less power and have far fewer problems.
Bob
On Mar 28, 2014, at 5:55 PM, Eric Williams
Hi
Normally that sort of circuit has a “boot strap” pull-up resistor that weakly
biases the diode to get things running at start up.
Bob
On Apr 3, 2014, at 11:08 AM, Javier Herrero jherr...@hvsistemas.es wrote:
Hello all,
I've a C OCXO (inside a Symmetricom 5045A that is inside an
Hi
Back when they were designing this stuff, they were very interested in getting
into the parts in 10 to the 15th. They didn’t get there, but that was the
desire.
Bob
On Apr 4, 2014, at 2:17 AM, Chuck Forsberg WA7KGX c...@omen.com wrote:
One needs to know the carrier frequency. Must be a
Hi
Here’s the issue about “big powerful 32 bit ARM processors”….
At the chip level (as in no board, just the bare part to solder down) their are
many parts below $1 and some below $0.50 in reasonable quantity (say 10K).
It’s hard to find a useful MCU of any sort below $0.25, so the “premium”
and you can use a 9V radio battery
for a power supply. I've bought some for under $3.But, yes some day
ARM will move down into this price point.
On Sat, Apr 12, 2014 at 9:23 AM, Bob Camp li...@rtty.us wrote:
Hi
Here's the issue about big powerful 32 bit ARM processors
.
Bob
On Apr 12, 2014, at 7:01 PM, Jim Lux jim...@earthlink.net wrote:
On 4/12/14, 12:50 PM, Bob Camp wrote:
Hi
I’ve been working with some friends on an ARM based Arduino project. The
support for ARM in the Arduino tool chain is still not really up to speed.
It’s actually been faster
Hi
I believe that you have a problem with that probe. A broken ground is one
possibility, a significant mismatch between the probe output and the scope
input is another possibility.
Bob
On Apr 17, 2014, at 1:32 AM, Claude Fender lab...@yahoo.fr wrote:
Hello List,
I've recently bought a
Hi
The dividing line between wander and jitter is a “legal one rather than a
physics one. It’s a breakpoint in a spec where the treatment of the noise
changes from “do this” to “do that”. In most cases you pass wander and you
attenuate jitter. Different specs put the line at different points
Hi
We used to do it with a microphone. Nothing fancy, just a simple little guy
with the inductance resonated out at 32 KHz. The output feed a computing
counter. It worked fine as long as the microphone was in contact with the watch
or watch module.
Bob
On Apr 18, 2014, at 7:25 PM, Bob
Hi
If you have a serial “thing” hooked to the GPS, pulling the sawtooth data out
of it is not very hard. They all have some sort of repeating message that
contains time / date / sawtooth information.
Bob
On Apr 19, 2014, at 4:58 PM, Bob Stewart b...@evoria.net wrote:
I've done as much as I
is disconnected. My assumption was that NTP would know the
secret handshake. Writing the software to extract the sawtooth is no
big deal. It has version 2.2 of the firmware.
Bob
From: Bob Camp li...@rtty.us
To: Bob Stewart b...@evoria.net; Discussion
commands to tell it to change this or change
that, but no clear path on how to talk to a UT+ that is mute but not bricked.
I'll go back through the PDFs I have. Maybe I just don't have the right
document.
Bob
From: Bob Camp li...@rtty.us
To: Bob Stewart
Hi
The WWII era FT-243 is one example of a crystal that has the active portion of
the electrodes separated from the resonator by an air gap. There are lots of
similar holders from that era that do pretty much the same thing.
Non-contacting electrodes are not very new.
Bob
On Apr 20, 2014, at
Bob Camp wrote:
Hi
The WWII era FT-243 is one example of a crystal that has the active portion
of the
electrodes separated from the resonator by an air gap. There are lots of
similar
holders from that era that do pretty much the same thing. Non-contacting
electrodes are not very new
B. Feher, EOZ Inc.
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960 office
908-902-3831 cell
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Bob Camp
Sent: Monday, April 21, 2014 9:17 AM
To: Discussion of precise time
Hi
If you are going to thermally excite the resonator, and measure the resonance
optically, there’s no reason at all to use quartz. There are other materials
with much higher acoustic Q than quartz.
Bob
On Apr 21, 2014, at 9:47 AM, Magnus Danielson mag...@rubidium.dyndns.org
wrote:
On
. They aren't plated
onto the quartz, but they are still in intimate mechanical and electrical
contact.
-Chuck Harris
Bob Camp wrote:
Hi
The WWII era FT-243 is one example of a crystal that has the active
portion of the
electrodes separated from the resonator by an air gap. There are lots
. Since it added time (and
complexity) to the process, it got dropped by most people to speed up
production …
Bob
On Apr 21, 2014, at 10:51 AM, Poul-Henning Kamp p...@phk.freebsd.dk wrote:
In message a5032606-d7d7-4231-b1bd-434670274...@rtty.us, Bob Camp writes:
Early in the WWII era, quartz
the quartz, but they are still in intimate mechanical and
electrical
contact.
-Chuck Harris
Bob Camp wrote:
Hi
The WWII era FT-243 is one example of a crystal that has the active
portion of the
electrodes separated from the resonator by an air gap. There are lots
of
similar
holders
by
multiplying by 18X. 8 x 18 = 144 MHz. Tooth paste moved them up and a small
scratch with a bit of solder moved them down.
Re: optically excite a quartz crystal? (Bob Camp)
As for Bliley - go to the web site and if you look around, you can find a
fascinating history
Hi
Roughly (very roughly) speaking, the series combination of C1, C2, C3 and L1
should equal the load capacitance of the crystal. If there is a varicap, it’s
likely in series as well. If the crystal is cut for series, then L1 resonates
with the caps in series.
You can put it on a Spice
HI
The circuit they show is not very low phase noise, so adding stuff is not going
to degrade it much. It will lower Q, but again, it’s not really Q limited over
most of the range.
The real issue with the circuit is that it has lousy load isolation.
Bob
On Apr 23, 2014, at 9:06 PM, Tom
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