Junk crystals are good thermometers. Ballpark is 1 ppm/degree-C
albertson.ch...@gmail.com said:
So does this mean I can epoxy a sandstone power resister to a junk crystal
and keep the frequency exactly perfect by varying the power in the resister?
Sure, for some values of perfect and such.
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
Hi
*IF* I understand the plot (and that’s a big if, it’s early and I’ve had
limited coffee): The period is shifting with phase. We trust the 3336 to be on
frequency. The likely answer is that the trigger point must be changing. The
question is whether it’s changing because the 3336 is doing
In message c542adee-19dd-4dab-a1bf-fb842c077...@rtty.us, Bob Camp writes:
The likely answer is that the trigger point must be changing.
Yes that would be my first theory as well.
The question is whether it's changing because the
3336 is doing something (small waveform changes) or because the
What about replacing the 3336 external reference with something like an HP
10811 and checking what difference, if any, that makes?
Regards
Nigel
GM8PZR
In a message dated 03/03/2014 13:42:33 GMT Standard Time,
p...@phk.freebsd.dk writes:
In message
In message 834d5.64e2b237.4045e...@aol.com, gandal...@aol.com writes:
What about replacing the 3336 external reference with something like an HP
10811 and checking what difference, if any, that makes?
The internal reference is an 10811 already ?
The point is not what delivers the reference,
On 3/3/14 2:18 AM, Hal Murray wrote:
Junk crystals are good thermometers. Ballpark is 1 ppm/degree-C
albertson.ch...@gmail.com said:
So does this mean I can epoxy a sandstone power resister to a junk crystal
and keep the frequency exactly perfect by varying the power in the resister?
Sorry, I must have missunderstood.
I realise the internal reference is already a 10811, but I thought there
was some concern that just the use of the external reference facility might
be in some way responsible, so if that was the case then perhaps using an
external 10811 might also be
In message 107931.7dbf8887.4045e...@aol.com, gandal...@aol.com writes:
I realise the internal reference is already a 10811, but I thought there
was some concern that just the use of the external reference facility might
be in some way responsible, [...]
No, I see no signs of that anywhere in
Uncorrelated noise improves resolution in certain systems, even
mechanical ones... it´s called dither:
http://en.wikipedia.org/wiki/Dither
Daniel
Em 03/03/2014 11:35, Poul-Henning Kamp escreveu:
In message 107931.7dbf8887.4045e...@aol.com, gandal...@aol.com writes:
I realise the internal
Wildwood is up as of 1300 Z March 3, 2014. We are in the middle of a lot of
snow! Estimated to receive a foot or so. Yippie...
73,
Bill, WA2DVU
Cape May
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Hello,
I am looking for the advise: what will be the better method to connect
GPSDO module by short extension cable to put its antenna input on front
or back panel ?
Lets say, GPSDO module has female “F” connector. And I would like to
have BNC connector on back panel of my project.
RG-59 cable is fine but soldering wires is not a good idea for 1.6GHz.
Use a panel-mount BNC crimp connector made for RG-59 such as the
Amphenol 31-343-RFX. I presume you want to use regular 50 ohm BNC types
rather than the 75 ohm variant.
It is preferred to use coax for the 1 PPS as any
Is it OK if I'll take some RG-59 from CCTV, cut 6 or 12 of it,
connect one end to GPSDO (let say this cable has compression type
connector) and solder other end to BNC on the panel ? Or its better
to use adapters and no soldering ? Like F connector-to-BNC adapter
, then short BNC-to-BNC
Hi Poul-Henning,
On 02/03/14 23:29, Poul-Henning Kamp wrote:
I have spent another evening playing around with the 5370 and the
conclusion is pretty ironclad now:
Running a 5370 with ext-ref locked to input frequencies is simply
a bad idea and should not be done.
Running it on the internal
On 03/03/14 14:14, Bob Camp wrote:
Hi
*IF* I understand the plot (and that’s a big if, it’s early and I’ve had
limited coffee): The period is shifting with phase. We trust the 3336 to be on
frequency. The likely answer is that the trigger point must be changing. The
question is whether it’s
It might also be worth noting that whilst manufacturers such as Trimble do
recommend the use of RG59 or similar 75 ohm cable for GPS module antenna
connections this is based on its lower loss compared with 50 ohm equivalents
such as RG58.
The connector itself on the GPS module, in most
Hi Poul-Henning,
On 03/03/14 14:41, Poul-Henning Kamp wrote:
In message c542adee-19dd-4dab-a1bf-fb842c077...@rtty.us, Bob Camp writes:
The likely answer is that the trigger point must be changing.
Yes that would be my first theory as well.
Cross-talk and ground-bounce through common
On 03/03/14 16:16, Daniel Mendes wrote:
Uncorrelated noise improves resolution in certain systems, even
mechanical ones... it´s called dither:
http://en.wikipedia.org/wiki/Dither
... as used in the HP5328A with option 40.
Got it. :)
PS. Still wish I had the GPIB for it.
Cheers,
Magnus
In message 5314e957.30...@rubidium.dyndns.org, Magnus Danielson writes:
Realize that I need to work on getting some GPIB programming done so I
can get some scripts going.
I've mentioned it before, but I'll plug it again:
https://github.com/bsdphk/pylt
The script I used for the plots I
In message 5314ef87.1020...@rubidium.dyndns.org, Magnus Danielson writes:
Got a HP3325B, HP5370B/C/D but also 5359A and SR535.
Another approach is to set a rubidium for a *slow* scan over
phase-relationships.
Hmm, I have a 5359A as well, I din't consider that as a possible
input source.
Hal,
For science-fair level accuracy try a $2 PTC-60 thermistor heater
one component oven for minimal complexity. I tried this with a
small box and insulating foam and it gives surprisingly good
results. Leave it to the ham radio guys to come up with a low
cost solution.
As a rule I'd say to minimize the number of connectors. The ideal is
to use one long cable but you can't do that. Soldering to connectors
is fine but it is really hard to do correctly with that double
shielded cable. The compression fitting are very good and even water
proof. I would use
Volker,
On 03/03/14 00:50, Volker Esper wrote:
Sorry for the time delay...
TIC: SR620 with Z3805 as external reference; signal source
Nortel/Trimble GPSTM (GPSDO) 10MHz output
Enclosed two plots (SW: Plotter):
- one is sigma(tau) calculated from phase samples (SR620 TIME mode),
- the other
On 03/03/14 22:35, Poul-Henning Kamp wrote:
In message 5314ef87.1020...@rubidium.dyndns.org, Magnus Danielson writes:
Got a HP3325B, HP5370B/C/D but also 5359A and SR535.
Another approach is to set a rubidium for a *slow* scan over
phase-relationships.
Hmm, I have a 5359A as well, I din't
On 03/03/14 14:23, Bill Riches wrote:
Wildwood is up as of 1300 Z March 3, 2014. We are in the middle of a lot of
snow! Estimated to receive a foot or so. Yippie...
Just don't blame LORAN for the snow. A LORAN tower will sure be far more
than a foot or so.
Good signal?
Cheers,
Magnus
In message 531505bc.4050...@rubidium.dyndns.org, Magnus Danielson writes:
On 03/03/14 22:35, Poul-Henning Kamp wrote:
In message 5314ef87.1020...@rubidium.dyndns.org, Magnus Danielson writes:
Indeed. Let's assume that it's not the BBB causing the issue, but it's
inherent to the 5370 design.
On 03/03/14 23:59, Poul-Henning Kamp wrote:
In message 531505bc.4050...@rubidium.dyndns.org, Magnus Danielson writes:
On 03/03/14 22:35, Poul-Henning Kamp wrote:
In message 5314ef87.1020...@rubidium.dyndns.org, Magnus Danielson writes:
Indeed. Let's assume that it's not the BBB causing the
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
On Mon, Mar 3, 2014 at 2:18 AM, Hal Murray hmur...@megapathdsl.net wrote:
Junk crystals are good thermometers. Ballpark is 1 ppm/degree-C
albertson.ch...@gmail.com said:
So does this mean I can epoxy a sandstone power resister to a junk crystal
and keep the frequency exactly perfect by
In message ab202da8-82bd-4861-af15-abbf92779...@rtty.us, Bob Camp writes:
If you are measuring temperature in a room who's temperature does not
change, then yes you can hold 0.1 C.
That would make you quite famous, since the current best measurement
of Bolzmans constant has a relative
The OCXO maker is forced to use a temperature sensor because he does
not have access to a frequency reference. If do have an external
frequency reference then the crystal itself makes a good thermometer.
So why not use THAT thermometer to control the heat added by the
resister.Such a system
Hi
The crystal as normally cut makes a very poor thermometer compared to a
thermistor.
Bob
On Mar 3, 2014, at 6:46 PM, Chris Albertson albertson.ch...@gmail.com wrote:
The OCXO maker is forced to use a temperature sensor because he does
not have access to a frequency reference. If do have
So does this mean I can epoxy a sandstone power resister to a junk
crystal and keep the frequency exactly perfect by varying the power in
the resister?
Sure. In fact you can loosely phase lock it to GPS that way. Your xtal doesn't
need to have an EFC pin. You are using external temperature as
Has anyone used the binary dump feature of the SR620 (command BDMP) or the
x1000 feature (command EXPD)?
If you have, please send me email off-list.
If you haven't, I will post a report to time-nuts later this week.
Thanks,
/tvb
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time-nuts mailing
Yes LORAN is sounding fine in Boston. Have a number of receivers on Autrons
SRS etc and checking local references. Good to hear the signal.
Also testing a fellow Time-Nuts LORAN C SDR that was posted about a month
ago.
Regards
Paul
WB8TSL
On Mon, Mar 3, 2014 at 5:46 PM, Magnus Danielson
Tom,
That's a pretty interesting idea. It makes me wonder if it would be worth it
to switch perhaps a 1/2W heat source (random number) off and on over the XO in
the UT+ say every minute or so.
Bob
From: Tom Van Baak t...@leapsecond.com
To: Discussion of
On Mon, Mar 3, 2014 at 4:51 PM, Charles Steinmetz csteinm...@yandex.com wrote:
What you are proposing is a disciplined oscillator using the oven setpoint
as the control input.
What I want to try is building a GPSDO for say $25 for everything
except the GPS.
A fun contest would be to adopt
My apologies to the list if this has been posted before but I found it
fascinating. I'm guessing this was early 60's.
I wonder if this practice continued until the advent of GPS? I be interested to
know if there was an interim technology and what it was.
http://youtu.be/SXV4c5eVkE4
Jim...
I think there were a couple of steps in between things like time-mation
satellites and such precursors to GPS. But I believe that CS references
were trucked around for a long time.
Regards
Paul
WB8TSL
On Mon, Mar 3, 2014 at 8:17 PM, Jimmy Burrell jimmydb...@gmail.com wrote:
My apologies to the
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 Jim,
Nice video. I had not see that old one before. Someone at NPL must be going
through archives. That's very nice of them to post it. Did anyone spot the date
of the filming?
My understanding is that the era of traveling clocks gradually ended as various
methods of satellite time
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
The piece didn't say anything about correcting for acceleration.
Regards.
Max. K 4 O DS.
Email: m...@maxsmusicplace.com
Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Woodworking site
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”
The piece didn't say anything about correcting for acceleration.
Hi Max,
True, but at one point the video mentioned microsecond resolution, and at that
level, no relativistic corrections for airplane trips are needed.
If you want to get down to nanoseconds, then yes, you will want to apply
Hi Skip,
Your message 30,30 is nearly identical to mine on 3-2-14 2:00mst
I just realized I been putting my time stamps as pdt should be pst (pacific
standard time).
Anyway the supperb time rate from svn64 prn30 changed from execellant to
average. Compareable to the other sats on
2/26/2014
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