Yes, I'm finishing rebuilding the PM6685 from a couple of part units,
then I'll try to use the GPIB card as is, but since the service manual
specifies clearly that the GPIB ROM FW version must match the mainboard
ROM FW version I do not expect it to work, as the current GPIB ROM is
clearly
Chris
Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W. Using a
switcher do generate 7 V 4.8 W and running the 7805 directly from 14.5 V
6.2.W. I use like you an IC temp sensor, two stage op amp driving a fan holding
the backplate temp constant and total power goes up to
Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)...
On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote:
Chris
Starting with 3.4 W used by the Tbolt my battery version burns 4.4 W.
Using a switcher do generate 7 V 4.8 W and running the 7805 directly
from 14.5 V
Thank you. Will look for it here under thermal pad.
Bert
In a message dated 8/27/2012 8:08:30 A.M. Eastern Daylight Time,
azelio.bori...@screen.it writes:
Here in Europe Farnell has the 3M thermal pad in sheets (105x150mm)...
On Mon, Aug 27, 2012 at 12:48 PM, ew ewkeh...@aol.com wrote:
Are these thermal pads temp conductive or insulative? If you want heat
dissipation why not use the readily available thermal grease used for
semiconductor mounting? Cheap and not really messy if applied correctly
jerry
-Original Message-
From: time-nuts-boun...@febo.com
On 08/27/2012 10:09 AM, Jerry wrote:
Are these thermal pads temp conductive or insulative? If you want heat
dissipation why not use the readily available thermal grease used for
semiconductor mounting? Cheap and not really messy if applied correctly
A layer of Kapton (polyimide) tape would be
There are components and traces.
Bert
In a message dated 8/27/2012 10:10:45 A.M. Eastern Daylight Time,
jster...@att.net writes:
Are these thermal pads temp conductive or insulative? If you want heat
dissipation why not use the readily available thermal grease used for
semiconductor
Hi friend! http://jesusmylifechurch.org/poganini112.html?dtopicid=1ynuo
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Michael wrote:
I'm still not entirely sure this is a good idea though, seems like a
low-temp oven for the whole tbolt would be better if you want
thermal stability.
Precisely because it is not clear that holding the backplate of a
Tbolt at a constant temperature is the best way to keep the
Sorry I thought the discussion was about the bottom case of the TBolt, not
the PCB, being in contact with a larger thermal mass.
jerry
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of ewkeh...@aol.com
Sent: Monday, August 27, 2012
Apparently the synchronization requirements are within a few seconds.
Wireless mesh process value transmitters have taken over the process
control industry. Some users require millisecond accuracy for the time
stamp on any alarm of event messages the device may send. Seems like
that would be a
On Mon, Aug 27, 2012 at 3:48 AM, ew ewkeh...@aol.com wrote:
te and am looking for the material switchers use between semiconductor and
cooling plate Any one know where I can buy it in sheet form?
Bert Kehren
What happens if you flood the entire assembly in transformer oil? Aside
from
Hi
All of the good stuff in a chrono is in the trigger part of it. Even with
very well designed triggers, there is a lot of ambiguity (by Time Nut
standards) in the measured time of flight. A simple time base and counter is
way more than adequate for the digital end of the device.
Bob
USB is a serial protocol and has some latency issues.
I am also involved with CNC machining and this has caused some issues in the
past. (the 'standard' is to use a parallel port or two)
The work around is to offload the timekeeping functions to an external box
and just use the USB to transfer
Hi
It's probably easier to put the TBolt inside a sealed box along with a small
/low speed / quiet fan. Let the moving air equalize everything. If vibration
is a concern, mount the fan on some sort of isolators.
Bob
-Original Message-
From: time-nuts-boun...@febo.com
There are thermal pads that are thermally conductive. You typically see
them in laptops and, oddly, optical drives. They're usually one or two
mm thick and very soft and squishy. Pull the bottom plate off any
full-size optical drive and you'll probably find one or two pieces. I
see lots of
Hi Azelio,
Sorry, the counters are 53131A, not 53151A. The A and B inputs are specified
from DC to 225 MHz with a sensitivity of y20 mV (rms) up to 100 MHz, 30 mV
(rms) 100 ~ 200 MHz, and 50 mV (rms) 200 ~ 225 MHz.
The problem can be at either input alone. The problem is only in the range
If the article is accurate, then it's not a real time server, pushing
out the time at regular intervals.
I started on a similar project, using GPSD and NTPD on a WRT54G. I had
problems getting all the various modules to cooperate on OpenWRT. I'll
revisit the project when I have time and see if I
amen to that, brother Bob!
Don
Bob Camp
Hi
All of the good stuff in a chrono is in the trigger part of it. Even
with
very well designed triggers, there is a lot of ambiguity (by Time Nut
standards) in the measured time of flight. A simple time base and
counter is
way more than adequate for
Hi Claudio,
I have inquired with the factory if they can provide the PROM. The contents
of that PROM have not changed since 2003 so we should be able to provide
one. They are on holiday today so when I hear something, I will let you
know.
On Mon, Aug 27, 2012 at 4:18 AM, Claudio
30mV are -13dBm so maybe it is why the -20dBm is not a suitable level for
that input. I have the 53132A and the 53181A so I can test (with the RS
SML01). Is this problem new? Never tested before?
About the OCXO aging: OK, I'm interested in the development of a model that
can be general enough so
Try switching the 50 ohm input impedance in and out a couple of times. This
has worked for me more than once in the past. I think it may be a sticking
relay or dirty contacts, etc.
Rich Stolte
AccuSource Electronics
I have several HP/Agilent frequency counters 53151A (and 53152A) in my
lab.
Isn't crystal aging marked by random jumps? perhaps lattice
rearrangement? Really hard if not impossible to model...
Don
Azelio Boriani
30mV are -13dBm so maybe it is why the -20dBm is not a suitable level
for
that input. I have the 53132A and the 53181A so I can test (with the RS
SML01). Is
So it can't be done... the possibility to discipline an OCXO taking the
action from a suitable model should help in speeding up the adjustments and
avoiding the humps as seen in the Allan deviation plot.
On Mon, Aug 27, 2012 at 9:31 PM, Don Latham d...@montana.com wrote:
Isn't crystal aging
I recently bought an HP 8720D 20 GHz VNA with options 010 (TDR
facility) and 1D5, which is the high stability time base. It's a
fairly old VNA (not supported since 2004), but it's not exactly a
dinosaur
Accuracy (23 deg C +/- 3 deg C) 10 ppm
The standard oscillator specs are:
Stability 0 - 55
However, since we are all nuts here, adding a GPSDO coulnt' hurt.
(Usually you shoot outside, so access to the sky should be easy!) Then
you'd also know position, which could be useful in accounting for
numerous other thing like coriolis acceleration, gravity due to
elevation, and gravity
I have an Isotemp OCXO (674-0010-000) an am wondering what is the recommended
value for the frequency trim pot?
Bud
W0LCP
Time is only there to prevent
everything from happening at once.
Einstein
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Hi again all:
Does anyone know where I can get a copy of Shera's PIC firmware for his
GPS-Based Frequency Standard?
Also, what enhancements are available for the latest firmware?
Thanks again,
Ron
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On 08/27/2012 10:14 PM, David Kirkby wrote:
I recently bought an HP 8720D 20 GHz VNA with options 010 (TDR
facility) and 1D5, which is the high stability time base. It's a
fairly old VNA (not supported since 2004), but it's not exactly a
dinosaur
Accuracy (23 deg C +/- 3 deg C) 10 ppm
The
On 08/27/2012 10:28 PM, Dan Kemppainen wrote:
However, since we are all nuts here, adding a GPSDO coulnt' hurt.
(Usually you shoot outside, so access to the sky should be easy!) Then
you'd also know position, which could be useful in accounting for
numerous other thing like coriolis
Hi;
Has anyone compared the 1130 and 1000B. Are they plug and play interchangeable
as far as VC. I have a few data sheets that spec each differently. It looks
like the 1000B has better Close in Phase Noise and the 1130 has better long
term stab.
Thanks;
Thomas Knox
Ron,
Here is Mr. Shera's actual web page on the topic. At the bottom you will find
the HEX file file for the firmware.
Don't ask as there is no published assembly listing of the firmware. Mr. Shera
does not feel like releasing it to the general public at this time.
Also, on that page is a
My starting point is the paper by Neubig on the real vs. predicted aging:
experimenting with the model and try to cut it around the Morion or the
Oscilloquartz OCXOs.
On Tue, Aug 28, 2012 at 12:15 AM, Don Latham d...@montana.com wrote:
There are ways of generating models, such as ARIMA, using
Several decades ago, the concept of the smart clock arose
at what was then HP. The idea was as discussed here to
characterize past aging, predict future aging, and
then correct the aging. The goal wasn't to turn a quartz
oscillator into an atomic clock replacement, but simply
to get the
Just testing.
My cloud/web based ATT e-mail address book was hacked.
ATT now has e-mail servers run by Yahoo. Drat!
Yahoo has a gaping security hole. My PW was not
hacked, but my address book in cloud storage was
used to send out spam. It was not a full copy of my
real address book,
I tried to attach to this email a datasheet for a very similar Isotemp 10Mhz
OCXO (Model OCXO134-10; PN 6624.2) the time-nuts server will not let me.
I am not certain whether the pins are the same as your model but I believe
all the Isotemp OCXO have same arrangement:
3. ELECTRICAL
Could you refresh me with the reference or email the paper? I'd like to
give it a read.
Don
Azelio Boriani
My starting point is the paper by Neubig on the real vs. predicted
aging:
experimenting with the model and try to cut it around the Morion or the
Oscilloquartz OCXOs.
On Tue, Aug 28,
The thermal pads are, generally, electrically 'insulative' but heat
'conductive'. However, the screws that are usually used to mount the TBolt
are metal and conduct electricity. Therefore, the main focus should be to
transfer heat for the purpose of keeping the TBolt at a constant
temperature.
Hi;
I am thinking of upgrading from a 1130 to a 1000B as a disciplined clean up
oscillator. As I look into this it appears the 1130 has an electronic tuning
range of 2-8vdc for +/-2E8. I cannot fine exact details on the 1000B, there
appears to be a opt 505 with a 0-10vdc range 506 with a +/-
Hi,
I'm just powering a new to me Datum Rb, Type 102500-001, LPRO for the
first time. The unit locks up quickly, and after about an hour, I checked
the Lamp voltage.
My unit is sitting at 6.9 VDC.
From the manual on Didier's site, below 3.0 or over 14 indicate failure.
Does anyone know whether
Hi Bill:
Okay, Thanks!
Ron
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of WB6BNQ
Sent: Monday, August 27, 2012 3:16 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Shera PIC Firmware file
Ron,
John only indirectly from other RBs and they are FRS's. They start off
higher 8-11 or so volts then come down to a lower value and sit there for a
long time. I would think you are mid to early life. More towards the mid.
But thats good for quite a few years.
Regards
Paul
WB8TSL
On Mon, Aug 27,
A friend emailed me that the North Koreans jammed GPS in May.
See:
http://arstechnica.com/information-technology/2012/05/north-korea-pumps-up-the-gps-jamming-in-week-long-attack/
This attack revives the controversy about LORAN-C shutdown.
Has anyody any recent info on the LORAN tests of last
Hi Bill:
I don't see the address for Shera's web page!
Thanks,
Ron
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of WB6BNQ
Sent: Monday, August 27, 2012 3:16 PM
To: Discussion of precise time and frequency measurement
Subject: Re:
Wondering if anyone has any practical suggestions as to the operation of stand
alone Datum 1000B's.Over the last 6 months or so I've acquired 3 of them
and I haven't been that impressed with their performance. I've got a nicely
running FTS 1050 and an 8600 series bva along with time lab
without any EFC I would expect it to be 1 Hz low. If less than 5 Volt will
get it on frequency I would use a 78L12 from your main supply followed by a
TI REF02. Worked for me.
Bert Kehren
In a message dated 8/27/2012 10:13:35 P.M. Eastern Daylight Time,
mspencer12...@yahoo.ca writes:
On 8/27/12 4:15 PM, Rick Karlquist wrote:
Several decades ago, the concept of the smart clock arose
at what was then HP. The idea was as discussed here to
characterize past aging, predict future aging, and
then correct the aging. The goal wasn't to turn a quartz
oscillator into an atomic clock
Hi Ron,
My apologies, I got to typing and forgot to append the URL line; which is:
http://www.rt66.com/~shera/index_fs.htm
Sorry about that ! If you haven't already it is worth reading the original QST
article which he has a link to at the bottom of the page.
BillWB6BNQ
Ron Ward wrote:
Hi Jerry ;
I assume you mean RFTGm-II-XO. The cell sites usually had an Andrew 26dB
antenna with a real short coax run. They also had a 40dB antenna option if
needed. Unless you have a long coax run the Symmetricom ant should be ideal. I
don't think the RFTGm-II-XO lock as quickly the
On Mon, Aug 27, 2012 at 7:33 PM, Jim Lux jim...@earthlink.net wrote:
On 8/27/12 4:15 PM, Rick Karlquist wrote:
Several decades ago, the concept of the smart clock arose
at what was then HP. The idea was as discussed here to
characterize past aging, predict future aging, and
then correct
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