Please read through the release note comments at the start of the heather.cpp
file in your Lady Heather installation directory for some info on the temco and
drift calculation features.
The drift numbers assume either a constant temperature or a decent DOXCO that
is not affected by
The closest thing to a manual is the comments at the start of the file
heather.cpp in your Lady Heather installation directory...
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BTW, Lady Heather has support for several versions of the Mayan and Aztec
calendars. Also Druid, Herbrew, Islamic, Indian, and many others.
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Yes, you can have a GPSDMC (GPS disciplined Mayan calendar). You can also
specify your preferred calendar correlation constant (a +/- offset to the start
of the calendar) to satisfy the whims of when your favorite deity demands
sacrifices.
Also, Lady Heather does sidereal time (LMST or
Although the Trimble oscillator has superb phase noise performance, it has
TERRIBLE temperature sensitivity. It appears to be a single oven oscillator,
not a double oven. The PWM'ed fan temperature control implemented in Lady
Heather effectively makes the unit a double oven. Also, by
I think only TIMER2 on the AVR has the clk/4 limitation. The other timers can
count at full speed.I know that I have counted at 8-12 MHz before...
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I did this on a lark one day. 5065A - doubler block - tbolt Seemed to work
very well, but I didn't do any serious testing of it.
---
There's a third alternative as well. You might consider using your 5065A as the
LO in a GPSDO. This will sacrifice some short- and mid-term
Lady Heather supports a digital clock display. You can zoom it to full screen.
It would not be difficult to add the two time zones to that display.
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No, the Thunderbolt does it and it works beatutifully. The GPS receiver
clock is derived from the 10 MHz oscillator. Voila, no messy sawtooth
corrections to deal with.
The Thunderbolt is a VERY user/hacker friendly design. Even if I were silly
enough to build my own GPSDO, I'd still
That type of behavior is almost always related to the driver for the USB
converter.--I am using a dedicated fast pro9cessor laptop but
Lady heather seems to
slo9w down and every 20-30 seconds I can see it race through the seconds to
catch up.
You have apparently not tried any modern/quality LED bulbs. The Sylvania
Ultra series have a 95 CRI (color rendering index). Bridgelux makes some
arrays with a CRI over 98. I defy you to tell the difference between the
output of those bulbs (or any LED with a CRI over 85) and halogens.
I have considerable experience with LED lighting. My house has over 300 light
bulbs in it! They are now all LED bulbs. You can read about some of it here:
http://budgetlightforum.com/node/9179
A few observations and recommendations:
Avoid all Chinese led bulbs. They spew more hash than a
The Kalman filter referred to in the status display refers to a Kalman filter
on the position, not the one used to discipline the oscillator during
holdover. The on;y device that I have seen that implements the Kalman
position filter is one of the Resolution-T models (I don't remember if it
Lady Heather will do it for you. It implements a nice temperature control PID.
All it takes is a small fan/transistor swith and an enclosure (cardboard box).
It uses one of the modem control signals on the serial port to PWM the fan
speed. The details are in the comments at the start of
The latest versions of Lady Heather work with the Resolution T and SMT
receivers.
Note that the Resolution SMT receivers only work at a fixed location. The -T
can be used in mobile applications.
___
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There was a blurb on the news tonight about a big honkin' solar flare that is
due to arrive around 6:00 AM tomorrow morning. It's supposed to be strong
enough to produce auroras visible as far south as the Gulf of Mexico and to
mess up GPS...
Nope, if implemented properly it works VERY well. No ADEV humps, no
vibration induced spurs, no commutator EMI, no power supply garbage.
Lady Heather's PID PWMs the fan to control the speed. It is not a bang-bang
controller. You should baffle the air flow so that it does not
I bought some low power 315 Mhz, 2400 bps transmitter and receiver modules to
use as a GPS data link. It turns out that the transmitter module can jam gps
within a half mile radius. Later, the maker of the modules disavowed all
knowledge of their existence
I talked with a guy that runs a company in China that makes flashlights. He
says that he gets reimbursed for his export shipping costs on items made in
China. That is why you see almost all stuff that is made in and shipped from
China on Ebay with free shipping.
--
Chinese sellers offer free shipping because their shipping cost is $0... the
Chinese government pays the shipping costs.
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?
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It should, if you are in UTC mode.
Does the Lady Heather / Thunderbolt show the leap second? It's present
in the alarms but can you watch/log the 23:59:60 event with this setup?
___
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Most of the SMT boards on the market come configured for TEP protocol which is
(somewhat) compatible with the Motorola receivers. You can use a program like
TRIMBLEMON to configure it for TSIP and 9800,8,N,1 serial format. Once you do
that, the latest version of Lady Heather will work with
Lady Heather can do sidereal time. Specify either the LMST, LAST, GMST or
GAST time zone (for Local/Greenwich Mean/Apparent Sidereal Time).
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You probably should not drive several devices in parallel from one output.
They may have fixed 50 ohm terminators. If not, it is best to daisy the
cable from one device to the next and terminate the end device with 50 ohms.
Also, that version of Lady Heather is very old. You should get
I saw a similar DAC jump when I replaced the SMB pigtail to my board. The
unit went into a brief holdover and came out with a shift in the dac vaue. I
would try wiggling the coax connection (without moving the board) and also
gently tapping around the board (maybe start with the oscillator
Does anybody out there have a Trimble NTPX GPSDO? If so, I'd like someone to
try it with the latest Lady Heather version that is compatible with the Nortel
GPSDO units. I can send you the .EXE file
___
I suspect that the 45000 is a cost reduced version of the NTGS0AA. It has to
be cheaper to produce and install a single board rather than two boards
connected by a cable. Also the 45000 has considerably fewer parts than the
NTGS50AA. They probably decided that they did not need as much
Most GPS receivers base their rollover point from their data of
manufacture/firmware creation/etc. The week rolls over 1024 weeks after that.
They tend to not be dependent upon when the actual GPS week rolls over.
Better receivers have ways of inferring the actual week after a rollover
I got in a couple of those Nortel GPSDO modules (marked 45000-00-B8 GPSTM).
These are the single board version of the NTGS50AA modules that have a separate
small front panel board.They are hardware and software compatible (mostly).
Some immediate differences popped up. The 45000 board
Is too true! The GPS signal sends the week number as a 10 bit integer number.
That number rolls over every 1024 weeks (call it 20 years). There is no
data sent that indicates which 1024 week cycle it is (some have been proposed,
but I don't think anything was ever implemented).
When / how the Thunderbolt responds to a rollover event (either raw sat signal
week number or internally biased week number based upon a fixed offset or date
of manufacture) is not known. The Trimble manual suggests that it adds a
fixed bias to the transmitted week number and evil things
You can buy windows (or coverings) designed to block RF. The most common
version blocks cell freqs/wifi/etc. Generally used with a matching wall
covering to keep your secret sauce from getting out.
While you're at it, add the window vibrator to give the laser microphones an
earful.
The ko4bb.com site has the info in the manuals section.
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and follow the
I got in another NTG50AA unit a couple of weeks ago and have been watching the
oscillator (Trimble 34310-T2) age in and stabilize. It started out aging at
around 1E-9 parts/day. After two weeks, the aging rate for the last 72 hours
was down to the 2E-11 range, with the curve still
What is the difference between the -T2 and plain -T???
The manufacturer that made them for Trimble...
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I got in a couple of Resolution-T receivers from fluke.l and have had a chance
to compare them with the Resolution SMT:
The -SMT receivers appear to be new. Mine were the TEP variant (Motorola
compatible) that has to be reconfigured to be TSIP compatible. The -T
receivers are used. Mine
It appears to be the same as the other one (which has an unreadable label).
This one is marked Trimble 0001-262T 34310-T2.
So far it appears to be oblivious to external temperature changes. I don't
know about its phase noise. The other unit had been running 24/7 for several
weeks. It
Yes. I once read that the 37265 was a double oven unit, but it appears to be
a single oven... and not particularly good oven. The 32765 oscillator's main
claim to fame is its wonderful phase noise performance.
--
Which version of the TBolt?
The one with the 37265 OCXO ?
The current version of Lady Heather on John's site does not have the Nortel and
Resolutuion T/SMT support in it. Sam posted a wake-up program here that can
get you started (or just send a BREAK to the unit then run Lady Heather). An
updated Lady heather will have some minor tweaks for
Much of the improvement seems to be in the better oscillator temperature
compensation... no telling how the phase noise is, but the Nortel osc has a
VERY flat aging curve and no detectable DAC changes with temp. I have several
tbolts and they all have a very temperature dependent DAC
An interesting test would be to test a Nortel unit and a Tbolt with the same
oscillator and see if the basic hardware had any difference in performance (I
bet they would be very close). One issue is the Tbolt can swing the DAC -5V ..
+5V, the Nortel from 0V .. +10V (with a default of 0V ..
While you're at it, add an ATMEGA328 processor and a 250 ps res/256 step delay
line. The processor reads the timing message, picks off the sawtooth
correction factor, converts it to an 8-bit value that it output on a port to
the delay line. The 1PPS signal clocks the port into the delay
No, actually it is for my alarm clock. Ignore the sawtooth? Poppycock!
What self-respecting time nut could possibly tolerate being woken up with a +/-
15 ns uncertainty...
---
If this is for a computer and NTP then you may ignore the sawtooth.
GPS receiver sawtooth
Actually, the option to set the PPS width is grayed out and that message is
not supported on the Resolution receivers.
I have caught the receiver doing some more bad things. Twice, it lost lock
for around 16 seconds, reported a bogus time/date (like 2024), and reported
bad UTC
Easy, in a precision lab you NEVER turn off the lights. That causes too big a
temperature shift. In fact, a warm body is a 100 watt heat source. That
extra heat load can easily affect precision equipment. And that's why zombie
technicians are in such high demand... the undead are always
My first inclination, if I were building a timing receiver, would be to make
the PPS output a nice, symmetrical square wave. But pretty much all GPS
timing receivers output an anorexic, dinky little heroin addicted supermodel
sized pulse (from 1 to 150uS wide is typical).
Well, the connector is a standard connector... it's just 2mm/0.070 spacing.
I would not trust a dropping resistor. The current consumption on these units
does not appear to be constant... the temperature plot varies depending upon
what it is doing (i.e. gets warmer when acquiring
Tom,
Send me your masers/cesiums and it'll save you the horrendous grief that those
pesky pulsey signals are causing you...
I still like 50:50 duty cycles. It makes das blinkenlights so much easier to
see.
It sounds like the -12V supply is used to generate the DAC low voltage
reference. If it is floating, the DAC output will be unstable. If it is at a
solid voltage, the DAC output will be stable. The standard EFC range for a
tbolt is -5V to +5V, but since almost all Tbolts are running the
Our friends from Old Cathay sell two versions of the Trimble Resolution timing
receiver: the -T and the -SMT.
The -T is a 12 channel receiver built of discrete components on both sides of
the PCB. It is spec'd at +/-20 ns accuracy (the sawtooth correction range).
It can be set up operate
I like Less than $20... Not for Sale Sounds like vaporcrap to me...
-
Or 216 channels (GPS L1/L2/L2C/L5; GLONASS L1/L2; Galileo E1/E5A):
http://www.javad.com/jgnss/products/triumph.html
I like Less than $20... Not for Sale Sounds like vaporcrap to me...
-
Or 216 channels (GPS L1/L2/L2C/L5; GLONASS L1/L2; Galileo E1/E5A):
http://www.javad.com/jgnss/products/triumph.html
It also makes the negative DAC voltage rail. The Tbolt DAC swings from -5V to
+5V. Lose the -12V and you can lose oscillator control.
-
The -12V is only used to support the RS-232 driver. The CPU should be running
and you should have discipline even without the
One nasty thing about these receivers is that they seem to be useless as a
general purpose GPS receiver. Once they have a saved position (even if you
erase the old one) it does not update the lat/lon/alt values (even if you put
the receiver into 3D mode). It does not even update
As a GPS receiver (12 channel), it seems to be quite good. It is at least
6dB more sensitive than the Thunderbolt.
You can also program the PPS output for PP2S (pulse per 2 seconds)
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The receivers from fluke.l are the TEP version that emulates Motorola protocols
by default. I used Trimble GPS Monitor V1.05 to set it for TSIP.
Select the Initialize Menu, Detect Receiver, click TEP protocol button. It
then found the receiver and offered to enable it for TSIP. Then
Why in the hell would anybody build a 50 channel receiver? At most you MIGHT
see 12 usable GPS sats... I don't think that I've seen over 10. WAAS should
be fairly useless for a timing receiver.
Supposedly the Nortel NTGS50AA docs and support info (including GPSMONITOR were
uploaded to the
I got a couple of these in and cannot get them to talk. There are two pins on
the connector that are labeled reserved and no-connect. The no-conect pin has
a trace going to (at least) a cap. Perhaps there is an enable pin? Has
anybody got these to work?
I have it running now. It turns out that the units from fluke.l come shipped
with TEP format messages enabled (it outputs @@Cf on power up). You have to
re-configure them for TSIP protocol and save the configuration back to the
unit. Hope to have Lady Heather taking to it. It does come up
I have poked and prodded the Nortel 8F-AE packet some more. Here is what seems
to be in it:
u08 subcode; // packet ID subcode
u16 zero; // ??? always zero
u08 leds; // led status
u08 ffom; // frequency figure of merit
u08 tfom; // time figure of merit
u08
The Nortel NTGS55A receivers output an undocumented 8F-AE data packet every
second. The Palisade receivers also output an 8F-AE packet, but it is totally
different. The last 8 bytes appear to be two 32-bit floating point numbers
that change every packet. One of the numbers appears to
The documentation says that you should use negative values to compensate for
the cable delay, but all of my units were removed from service with positive
or zero delays set. Lady Heather sort of assumes positive values, but you can
enter negative ones. Which is correct remains a mystery
I think the tbolt may need to go through two 12.5 minute almanac cycles before
it updates/outputs all its data...
The first thing to do to improve performance is to run the a oscillator
autotune command. This will determine the correct osc gain and initial DAC
settings. It will also set the
With a rather freaky display that I have never seen:
http://www.electricstuff.co.uk/venner.html
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You are not going to get anywhere near sub-mm levels without doing L1/L2
measurements with a geodetic grade receiver and thermally stabilized antenna
(and receiver/cable). With a patch antenna (which is in a lot of timing
antenas) on a geodetic L1/L2 receiver you can see 1 meter errors!
Lady Heather has a command line option that causes it to send an initialization
string to the tbolt.
Try adding =10,3c,10,03 (without the quotes) to the command line. Perhaps
repeat the four hex values a few times. There is no 300 msec delay command.
There is also a $10,3c,10,03 (without
Looks like my keyboard is on the way out... seems to want to type 8's for 6's
and a few other keys are also glitching.
I think HP charged $60,000 for their first cesium clocks.
---
But, how much DID a cesium clock cost in 1966?
One of the nose-bleed channels (MeTV) just showed an old 1980's Batman show
where the infamous, evil, dastardly villain Clock King attempted to steal a
Cesium Clock (worth over one million dollars!). He was unsuccessful and is
still out there. All time-nuts, protect your Cesium Clocks!
Lady Heather has a sidereal time display (LMST or GMST).
With some work, you could modify the code to pulse one of the modem control
signals as a PPSS signal. The res would not be the best (probably 50 msecs
would be easily achievable)
That sort of behavior is usually traceable to USB serial port driver issues.
I have run the program just fine on a 90 MHz Fujitsu Milan laptop with passive
matrix LCD display.
-
BUT: A single second tick takes about 3-4 seconds to show up..
The roots of Lady Heather lie in a program written in the mid 1980's for
controlling a Magellan GPS board (a multiplexed single channel receiver - Bruce
has it now). That program ran under DOS. The code is pretty much straight
ANSI C. I modified it to work with the Tbolt and added the
Lady Heather's osc drift rate calculation does assume that the temperature has
been stabilized. John DuBois and I did quite a bit of work to find a way to
unwind the osc parameters from the available unstabilized reported data using
SciLab on the log files, but nothing seemed to work
Lady Heather supports several versions of the Mayan and Aztec calendars (plus a
bunch of others). You can also specify a correlation constant offset to match
the date to whatever value your local high priest deems correct.
---
I thought the same thing but I think Mark
John,
Did you ever run any tests on those UCT double oven OCXOs? I've found them to
be freaky-stable long term. I have retrofitted a lot of Tek DC510/5010
counters with them and after over two years, the last digit is still right on.
They are capable of great
It's slated for destruction around December 21 of this year...
We already have one of those that everybody can use. It's called the
earth.
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Uhhh... last time I checked 3V/330 ohms is 9.1 milliamps, not 90 mA...
-
Just calculate: 5V supply, approx 2V LED voltage - 3V over the resistor.
3V/330R = 90mA
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The Tbolt does not have any sawtooth error or corrections. Its' GPS receiver
LO is generated from the 10 MHz oscillator. That's what makes it the best
GPSDO out there.
--
I'm also thinking of porting over much of the Lady Heather t-bolt monitoring
stuff to the Arduino.
These are 4-BYTE single precision floating point numbers, not 4 bit integers.
They are the values plotted in the Lady Heather PPS and OSC graphs (and used
in the ADEV calculations and plots (not actually true ADEV values since they
are not refereneced to an external reference, but still
I have had several HP-5370's with the 10544 oscillator. They consistently
have much less long term frequency drift than the 10811's. If they have not
been powered on for a long time, they do take a couple of months of power-on
aging before they settle in.
Google water slide decals for everything you want to know and need... there
will also be links for rub-on decals.
And check out tagopappadecals.com for info and supplies for making water-slide
decals (like used on model cars and airplanes). They can also make decals for
you.
Check out http://dorkbotpdx.org/wiki/pcb_order You get three boards for
$5.00 per square (or round, triangular, oval, etc) square inch ($1.67 sq/in).
No setup charge, no shipping charges in the USA. Top quality boards (gold
plated) made in the USA. You can send him Eagle or Gerber
How about using Hostess Twinkies? They look like they would have good
insulating properties and are well known to never, ever decompose ;-)
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Lady Heather depends upon the ability of the Thunderbolt to broadcast the time
message automatically every second. Apparently the Palisade type units do not
support this mode of operation. It might be possible to set up the software
so that it requests the time message continuously and
The good Lady Heather can display temperature values in all sorts of archaic
measurement systems. And buried in there somewhere (I think its still there)
can display phase errors in femtofortnights.
I once worked for a company famous for its insistence on endless specs and
paperwork that
If you have a Thunderbolt, Lady Heather will sync your time for free... It
can sync the time via a keyboard command (TS) or via command line options on a
regular basis, or whenever the system clock and GPS clock differ by a given
amount. You can specify the inherent delay between the
1 ppm at 10 MHz is 10 Hz. It's been quite a while since I tested it, but if
I remember correctly, if the Tbolt OCXO is off that far the GPS won't lock and
the failure will be rather obvious.
The typical Tbolt oscillator has a DAC gain of 3.5 Hz/V. 10 Hz would be 3V of
DAC offset. Lady
I believe that the Thunderbolt firmware would catch such a thing.There is
quite a bit of error checking and TRAIM (time receiver autonomous integrity
monitoring) done.
If the osc was off in freq, the firmware would try to use the EFC voltage to
slew it back into agreement with the GPS
I have used a company in Wyoming called Bomarc Services to reverse engineer
boards. They work for dirt cheap and do an excellent job. If you let them put
the results in their resale library, they work for cheaper than dirt.
I seem to remember that their rate was around $20 and hour... half that if you
let them put the results in their for sale library.
They did a 6x8 four layer board with components on each side for less than
$250. It had a off-the-shelf DC-DC converter brick on it... the board came
back with
Using the cable delay message is probably not a good idea... it resets the
internal filters and state every time you change it.
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Yes, at one time there was some very precision surveying antennas that were
temperature controlled. I'm not sure if they were just controlling just the
preamp or the whole antenna, but I got the impression that they were
controlling the temperature everything inside the radome package.
At
I now have my house converted over completely to LED bulbs... over 300 of them
(mostly PAR16/PAR20/PAR30/PAR38 bulbs)! At retail the cost would have been
over $15,000 dollars!!! Totally insane... I have a large closet totally
dedicated to light bulbs.When incandecents/halogens are no
All this talk of old digital clock chips reminded me of my first digital
clock... built almost 40 (EGAD!) years ago with a Mostek MK50252 clock chip
from Radio Shack (when those words weren't a travesty). And it had utterly
unbobtainium GREEN LED displays. It stopped ticking in the last
I checked my neutrino detector yesterday and detected some of those faster than
light neutrions tomorrow ;-)
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The S A D data display plots the raw signal level data... it is basically the
satellite position map with the trails showing the signal level.
The S A S signal display does an interpolation between the various satellite
signal level data trails to fill in the blank spaces in the signal
No, more like two months! It typically takes a couple of MONTHS for an
oscillator that has not been used in a long time to stabilize! This is very
evident when firing up an old HP 5370 or Thunderbolt.This extended period
of time is why people leave their oscillators powered at all
Lady Heather's precision (nominal 48 hour) survey collects data over multiple 1
hour periods. With 48 hours of data, multipath and transient disturbances are
minimized. It applies weighted median filters to the data and does other
statistical analysis to arrive at a final location. With a
Yeah, but it leaks oil like a sieve and the blinkenlights go out when it
rains...
Come now, it's British, it's got to be better!
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The specs says that the sine output requires a 390 pF cap to ground for
filtering. Still, it is rather distorted and ragged. It almost looks like
that they added the sine wave output as an afterthought and don't expect
anybody to actually use it. On the units that I have, it is useless
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