> For a thermal fuse to make any use, it needs to be in the oven
Which this one isn't, in any event. It's outside the oven and its
insulation layer. Completely useless for protecting anything.
> but for
> pure over-current protection and external normal fuse will work, which
> is what he propo
Several months ago, I purchased new thermal fuses from HP. I can't remember
how I came up with the part number, probably out of a 5061B manual or
something, but when I searched Agilent parts, there it was. It was only $3
or $4 for the $0.10 part but it put it back in 'original' condition. As I
r
Rick,
Richard (Rick) Karlquist wrote:
paul swed wrote:
Or simply fuse externally with a reasonable fuse holder and fuse.
No, you don't understand. It is a THERMAL fuse. It must be IN
the oven to do any good. There is definitely no excess room
inside of the 10811 to add a fuse holder.
F
paul swed wrote:
Or simply fuse externally with a reasonable fuse holder and fuse.
No, you don't understand. It is a THERMAL fuse. It must be IN
the oven to do any good. There is definitely no excess room
inside of the 10811 to add a fuse holder.
Rick Karlquist N6RK
_
Bill Hawkins wrote:
Magnus,
I learned a technique for adjusting time that doesn't require floating
point calculations, back when a FP Package significantly slowed micro
processing, circa 1980.
I still remember those times, even if I did not do any computing then.
Use a preset counter to coun
Hi
Diodes rarely fail half way. Either a bond wire goes out or they melt down. If
the varicap looks like a diode at DC it should be ok at RF. I would look
elsewhere for the problem.
Bob
On Jan 15, 2010, at 11:07 PM, Neville Michie wrote:
> Hi, thanks for the constructive comments.
>
> I too
Hi, thanks for the constructive comments.
I took both units out of their cases and gave them a visual inspection.
I tested the varicap diode as a diode, and checked the values of
surrounding resistors.
When I re-assembled them one of them now works OK. It will take some
time to see if it is s
Hi
My guess would be that the crystal filter strips the phase noise off of the
multiplied 15 MHz and then the little amps boost it back up. If that is indeed
what they are doing, the amps should be pretty quiet when running fairly high
power signals.
Bob
On Jan 15, 2010, at 10:43 PM, paul sw
No, the design is such that one actually requires a well matched pair
for the cascode or the gain ratio between the collector that drives the
output and that which drives the agc detector to have the desired value
of 1x.
The amplifier design isnt a good one as the high differential dc gain
fr
Hej Bruce,
Bruce Griffiths wrote:
Hej Magnus
No one bothers with such gear ratios for a modern telescope as its
cheaper to use a computer than have a set of custom gears made.
In any case, direct drive of the axes is sometimes used - no gears:
http://www.halfmann-teleskoptechnik.com/e_index.h
Here in Minnesota, at 93 W, 44 N, there was no correlation in the
magnitude or direction of EFC in a pair of Z3801As with antennas
four feet apart. I'm surrounded by trees, and have the elevation
mask set at 39 degrees.
Both units have about 15000 hours of running time.
The following numbers come
Actually the little rf amps pretty nice. It will take any signal in and
amplify it so that you can use a 7 way passive splitter for frequency
distribution. At least thats how mine worked.
Its pretty efficient. Can't speak to the noise quality.
On Fri, Jan 15, 2010 at 10:32 PM, Bob Camp wrote:
>
Or simply fuse externally with a reasonable fuse holder and fuse.
Over the years I have seen fuse fail due to simple age. Nothing more.
On Fri, Jan 15, 2010 at 9:36 PM, Tom Holmes, N8ZM wrote:
> HI Rick...
>
> That helps a lot. It also tells me the real reason why the fuse is open
> ;-(.
>
>
> Th
HI Rick...
That helps a lot. It also tells me the real reason why the fuse is open ;-(.
Thanks!
Regards,
Tom Holmes, N8ZM
Tipp City, OH
EM79xx
-Original Message-
From: Rick Karlquist [mailto:rich...@karlquist.com]
Sent: Friday, January 15, 2010 8:48 PM
To: thol...@woh.rr.com; Discuss
Magnus,
I learned a technique for adjusting time that doesn't require floating
point calculations, back when a FP Package significantly slowed micro
processing, circa 1980.
Use a preset counter to count incoming pulses, perhaps 1 PPS. Set it
for the number of pulses that will make a one pulse adj
Hi
I'm sitting here stripping LPRO-101's out of RFG-RB's and kind of wondering
about the other "fine stuff" on the PC board. About the only thing that looks
useful appears to be a 15 MHz crystal filter made by either PDI or Netcom. Has
anybody gone to the trouble of pulling one off the board an
Rick Karlquist wrote:
Tom Holmes, N8ZM wrote:
While on the subject of 10811's, I have one which appears to have a blown
fuse. Bypassing same, it seems to work OK, so suspect that tiny filament
or
whatever simply succumbed to some shock or vibration, or maybe just old
age.
I don't recall the curr
Magnus Danielson wrote:
J. Forster wrote:
That's the point I was making earlier.
Most telescopes have a FOV of at least 15 arc-minutes. You only need to
get the guide stars into the field and go from there.
Also, a telescope's pointing can be off in BOTH RA and Dec. Dec has
nothing to do with
J. Forster wrote:
That's the point I was making earlier.
Most telescopes have a FOV of at least 15 arc-minutes. You only need to
get the guide stars into the field and go from there.
Also, a telescope's pointing can be off in BOTH RA and Dec. Dec has
nothing to do with siderial time.
While di
Bert that is helpful. I can see that pretty much the 10544 output is that
ic.
Bruce there is a cap feeding it if the signal is clean there and the voltage
is fine feeding the chip it would tend to be the ca3045. That could be
replaced by many modern amplifiers if the chip could not be obtained.
On
Rick,
I'm pretty sure there was a 10811A Service Note issued on the fuse
problem.
IIRC, the early production units used a relatively low temp fuse,
which proved
painful & was replaced by a higher temp version(maybe twice). I had
one of
those early units & it failed 2x before I gave up & ca
Digi-Key sells a number of thermal fuses.
-John
=
> Tom Holmes, N8ZM wrote:
>> While on the subject of 10811's, I have one which appears to have a
>> blown
>> fuse. Bypassing same, it seems to work OK, so suspect that tiny filament
>> or
>> whatever simply succumbed to some shock or
Hi Nigel,
You are right it is A002206.G1 I must have pressed the wrong keys.
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: "gandal...@aol.com"
To: time-nuts@febo.com
Sent: Fri, January 15, 2010 6:55:48 PM
Subject: Re: [tim
Tom Holmes, N8ZM wrote:
> While on the subject of 10811's, I have one which appears to have a blown
> fuse. Bypassing same, it seems to work OK, so suspect that tiny filament
> or
> whatever simply succumbed to some shock or vibration, or maybe just old
> age.
> I don't recall the current draw now,
Hi Nigel,
Thank You so much for all the information, I will download the files and will
advise if I require further help, as I have mentioned I received the receiver
only no documentation and must purchase GPS Antenna and built a power supply I
may be asking You for more help as I assemble the
No the picture is not the same.
Sal
From: Bruce Griffiths
To: Discussion of precise time and frequency measurement
Sent: Fri, January 15, 2010 6:07:31 PM
Subject: Re: [time-nuts] need help on Tbolt
Are you sure that it isnt a Thunderbolt E which is some
Thank You for the links it will help
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Stanley Reynolds
To: Discussion of precise time and frequency measurement
Sent: Fri, January 15, 2010 5:59:08 PM
Subject: Re: [time-nuts] n
While on the subject of 10811's, I have one which appears to have a blown
fuse. Bypassing same, it seems to work OK, so suspect that tiny filament or
whatever simply succumbed to some shock or vibration, or maybe just old age.
I don't recall the current draw now, but it seemed reasonable at the tim
No one has mentioned the fact that the cathode of the varactor
is connected to an internal 6.8V Zener diode voltage reference.
This is another source of trouble.
Rick Karlquist
N6RK
Bob Camp wrote:
> Hi
>
> I sure would do some quick continuity checks on the EFC line before I
> started swapping
ewkeh...@aol.com wrote:
Attached is a scan of the schematic of the 10544 vintage 1976 given to me
by HP as part of TI's work on the first GPS receiver. Maybe it will help.
Bert Kehren
That circuit appears to be for the early, higher phase noise version.
The later version extracts t
Hi
I sure would do some quick continuity checks on the EFC line before I started
swapping varicaps out. A bum solder joint opening up is a lot more likely than
the varicap going nuts in a fashion that still lets the oscillator run.
Bob
On Jan 15, 2010, at 7:08 PM, Neville Michie wrote:
> Hi
Attached is a scan of the schematic of the 10544 vintage 1976 given to me
by HP as part of TI's work on the first GPS receiver. Maybe it will help.
Bert Kehren
HP 10544-2.pdf
Description: Adobe PDF document
___
time-nuts mailing list -- time-nuts@f
There's no internal bypassing of the EFC line in the 10811A at all.
Bruce
J. Forster wrote:
Here's a guess: Is there an electrolytic capacitor that bypasses the EFC
to GND? Maybe that's bad. I don't have a schematic.
-John
==
Hi,
I have two HP10811 oscillators that do not
In a message dated 16/01/2010 00:08:36 GMT Standard Time,
namic...@gmail.com writes:
While I am playing with them I may try to readjust the temperature
setting
of the oven to get on top of the turnover. Can anyone point me to
that article?
---
Perhaps this one?..
Here's a guess: Is there an electrolytic capacitor that bypasses the EFC
to GND? Maybe that's bad. I don't have a schematic.
-John
==
> Hi,
>
> I have two HP10811 oscillators that do not respond to EFC voltage.
> The latest to fail had been quite accurately set against a TBOLT,
> o
Hi,
I have two HP10811 oscillators that do not respond to EFC voltage.
The latest to fail had been quite accurately set against a TBOLT,
one morning (after being on standby in a HP5328A) it was off frequency
and would not shift with EFC but would adjust with the coarse adjust.
I have bought in tw
In a message dated 15/01/2010 23:07:48 GMT Standard Time,
bruce.griffi...@xtra.co.nz writes:
Are you sure that it isnt a Thunderbolt E which is somewhat different
from the earlier models:
---
It's definitely a Thunderbolt, with revision E firmware.
I have two similarly labelled,
Lady Heather saw all the yackety yack on Sideral time... in the next beta
release you will be able to specify GMST, GAST, LMST or LAST as the time zone
name and have yourself a GPSD sidereal clock (with digital or analog time
display)...
In a message dated 15/01/2010 21:51:49 GMT Standard Time,
salc...@rogers.com writes:
Can someone help with the software for a Tbolt 35757256 built 6/2/05
A002206,61 Rev E, I just received this unit from China without any information
or manual or software, I am about to built the power sup
Are you sure that it isnt a Thunderbolt E which is somewhat different
from the earlier models:
http://trl.trimble.com/docushare/dsweb/Get/Document-383329/022542-010B_Thunderbolt-E_DS_0807.pdf
Can you post some images?
Bruce
Stanley Reynolds wrote:
Have you seen this:
http://www.leapsecond.c
I found the problem I had under Firefox browser.
The video driver, as a cause, didn't make sense to me because the site
will run if I use IE rather than Firefox and I do check for updates
periodically.
In Firefox I disabled all extensions and most add-ins that I have added
to Firefox. Then t
Colby Gutierrez-Kraybill wrote:
I love following the broad tangents that come up on this list...
I wanted to chime in on observatory use of sidereal time, and guider
scopes, etc... At the research class instrument level, as is being
pointed out (har har), pointing models are heavily used, fo
Have you seen this:
http://www.leapsecond.com/pages/tapr-tbolt/
and
http://www.prc68.com/I/ThunderBolt.shtml
Stanley
- Original Message
From: SAL CORNACCHIA
To: Discussion of precise time and frequency measurement
Sent: Fri, January 15, 2010 3:51:20 PM
Subject: [time-nuts] need he
Lux, Jim (337C) wrote:
On 1/15/10 9:13 AM, "J. Forster" wrote:
Heresy:
Why do you really NEED super accurate siderial time? If you are using it
to point a telescope, you only need it accurate enough to get the guide
stars into the field. Remember, the atmosphere refracts kinda randomly.
-J
Note the early version has a different (tighter) spec for the oscillator
supply and oven controller supply (10.6V-11.7V) than the later version
(11V - 13.5V).
The oven supply spec is also different (15V -30V) rather than (20V-30V).
Bruce Griffiths wrote:
Nick
Nick Foster wrote:
Do you have t
Nick
Nick Foster wrote:
Do you have the serial number of your 10544?
1244A02119
That appears to be the early, higher phase noise version.
The later versions have a 15-20 dB lower phase noise floor.
One clue (apart from the serial number prefix) to this is that the
CA3045 diff
I love following the broad tangents that come up on this list...
I wanted to chime in on observatory use of sidereal time, and guider
scopes, etc... At the research class instrument level, as is being
pointed out (har har), pointing models are heavily used, for both
first acquiring a sour
On 1/15/10 9:13 AM, "J. Forster" wrote:
> Heresy:
>
> Why do you really NEED super accurate siderial time? If you are using it
> to point a telescope, you only need it accurate enough to get the guide
> stars into the field. Remember, the atmosphere refracts kinda randomly.
>
> -John
What i
> Do you have the serial number of your 10544?
1244A02119
> But this would depend on if the CA3045 were used in the oscillator.
The CA3045 is only used on the buffer board. The oscillator uses several TO-5
transistors and a 2N3904.
> Is the board shown actually the oscillator board or just th
Hi,
Her we use the following Java applet, on a computer synchronized through
NTP:
http://www.gb.nrao.edu/~jbrandt/jLSTclock/
Its precision is enoughy for our need (we're an astronomical observatory, by
the way)
About the math, the basic relation is that there is one sidereal day more in
a sid
Performance of an early pointing model for the MMT is given in:
http://www.mmto.org/MMTpapers/pdfs/tm/tm03-3.pdf
Pointing error performance was around 1.6 arc sec rms
Bruce
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--- Begin Message ---
Of course not, but that isn't relevant either to the original thread or
the general problem of pointing.
But while we are discussing the MMT it has an altazimuth mount,
Both axis coordinates are dependent on the local apparent sidereal time
when tracking celestial objects
--- Begin Message ---
Finder charts are of no use with either an inexperienced observer or an
automated telescope.
Bruce
J. Forster wrote:
My girl friend is a regular observer (w/ a PhD) at the Smithsonian
Astrophysical Observatory and uses the instruments at Mt. Hopkins all the
time. I KNOW
Didn't some of the 5345 or 5328 manuals have schematics for the 10544. I
have no idea if it's in the on-line manuals but I recall seeing the
timebases in some.
Phil
- Original Message -
From: "Bruce Griffiths"
To: "Discussion of precise time and frequency measurement"
Sent: Friday,
Can someone help with the software for a Tbolt 35757256 built 6/2/05 A002206,61
Rev E, I just received this unit from China without any information or manual
or software, I am about to built the power supply for it and would appreciate
any help possible
Best regards,
Sal C. Cornacchia
Electr
Nick
The 10544A had at least 2 variants.
I have the originals but the various datasheets are available on Didiers
site.
The earlier versions had a somewhat higher phase noise spec, as can be
seen from the datasheets with different dates.
There was a significant change to the circuit to achieve
Bruce,
The 10544 I have doesn't correspond to the 10544 schematic I found on
leapsecond.com. Here's a photo of the AGC board inside mine:
http://www.nerdnetworks.org/~bistromath/photos/misc/10544.JPG
It's an RCA CA3045 array instead of the 3094's used in the schematic I saw.
Looks like the be
You have missed the point entirely.
Autoguiders etc are only useful for tracking an object once it has been
acquired.
Pointing is the ability to point the telescope at a desired object or
location starting from home or another position in the sky.
With large telescopes (or with inexperience
> J. Forster wrote:
>> The two big ones I remember are:
>>
>> A Boller& Chivens 24" about 1 degree
>>
> Only with a camera, not with an eyepiece.
True, but telescopes have guide scopes with much shorter focal lengths,
typically 1 vs 9 meters.
> Eyepiece field of view is something like 20 arc m
> J. Forster wrote:
>> That's the point I was making earlier.
>>
>> Most telescopes have a FOV of at least 15 arc-minutes. You only need to
>> get the guide stars into the field and go from there.
>>
>> Also, a telescope's pointing can be off in BOTH RA and Dec. Dec has
>> nothing to do with sideri
J. Forster wrote:
The two big ones I remember are:
A Boller& Chivens 24" about 1 degree
Only with a camera, not with an eyepiece.
Eyepiece field of view is something like 20 arc minutes with a 2" eyepiece.
A 60" about 15 arc-minutes
The MMT is about 1 degree, I think.
These are all OPEN LOOP corrections. They are better than nothing, but
nowhere near as good as properly implemented auto-guiding which is closed
loop.
They are certainly not as good as even the simplest Adaptive Optics
utilizing only a Tip-Tilt tracker.
-John
==
> One needs to k
J. Forster wrote:
That's the point I was making earlier.
Most telescopes have a FOV of at least 15 arc-minutes. You only need to
get the guide stars into the field and go from there.
Also, a telescope's pointing can be off in BOTH RA and Dec. Dec has
nothing to do with siderial time.
If th
The two big ones I remember are:
A Boller & Chivens 24" about 1 degree
A 60" about 15 arc-minutes
The MMT is about 1 degree, I think.
-John
=
>
> j...@quik.com said:
>> Why do you really NEED super accurate siderial time? If you are using
>> it to point a telesco
That's the point I was making earlier.
Most telescopes have a FOV of at least 15 arc-minutes. You only need to
get the guide stars into the field and go from there.
Also, a telescope's pointing can be off in BOTH RA and Dec. Dec has
nothing to do with siderial time.
-John
==
[snip
The output of the diode detector is compared with the dc base voltage of
the oscillator transistor adjusting the oscillator transitor current
whenever the detector output deviates from
Oscillator transistor base voltage - 2*Vbe.
Bruce
Nick Foster wrote:
Thanks for the quick reply, John.
One needs to know the local apparent sidereal time to aid initial
acquisition of the target.
Periodic error correction and using an autoguider are of little or no
use for this operation.
However correction for encoder error axis non orthogonality, encoder
eccentricity and bending of the telesc
j...@quik.com said:
> Why do you really NEED super accurate siderial time? If you are using
> it to point a telescope, you only need it accurate enough to get the
> guide stars into the field. Remember, the atmosphere refracts kinda
> randomly.
What's the field of view of a telescope? (or the g
Hi Rex - I suspect that you have a video driver bug. Click on start - all
programs - Windows update, click on the custom button. (Do the single
required update first if it asks.) Over on the left side, find Hardware
updates - see if there is a video driver update. Alternatively, go to the
card
Thanks for the quick reply, John.
> From: jmfra...@cox.net
> Okay, 12V on the oscillator (pin 3) and 20V on the oven (pin 14). How much
> on the oven controller, pin 8?
+12V. The oscillator uses the same supply as the filter, with the addition of a
10mH inductor + decoupling caps.
> Are pins
I'm not sure your friend needs the time at all. Telescope tracking
mounts have a periodic error due to non-perfect mechanical parts. The
usual way to remove this error is to "train" the mount by manually
guiding it through one or more periods, or - probably more common these
days - use an opt
If you actually need the apparent local sidereal time then the
corrections detailed at:
http://www.usno.navy.mil/USNO/astronomical-applications/astronomical-information-center/approx-sider-time
may be necessary.
Bruce
Brooke Clarke wrote:
Hi Brian:
Why? Do you just want to see the sidereal
The 10544A is specified for a 1000 Ohm load.
John WA4WDL
--
From: "David C. Partridge"
Sent: Friday, January 15, 2010 3:11 PM
To: "'Discussion of precise time and frequency measurement'"
Subject: Re: [time-nuts] HP 10544A with dodgy output?
What impedance loading is the output specified for? 1M or 50R.
Could I suggest using a distribution amp?
Dave
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Nick Foster
Sent: 15 January 2010 19:53
To: time-nuts@febo.com
Subject: [ti
It sounds like the dc emitter current for the output emitter follower is
too low.
Either that or the emitter follower transistor is faulty.
It is possible to damage the output emitter follower, it happened in one
that I had several decades ago.
Once the output device was replaced the OCXO func
Okay, 12V on the oscillator (pin 3) and 20V on the oven (pin 14). How much
on the oven controller, pin 8?
Are pins 2, 4, 5, 9, and 15 grounded? Pin 6 (EFC) should be grounded for
initial testing.
John WA4WDL
--
From: "Nick Foster"
Sent: Frida
Lots of fun little details to worry about managing
ws) TOO True.
A temporary attenuator bypass switch or syncing at a higher freq are two of
many ways to help the initial lock up delay caused
when a high value Dac attenuator is used to lower the effect of EFC noise
and / or to increase
Brian,
Last I looked, the solar/sidereal ratio was in fact 1:1.00273790935
though that was a while back. I build "precision" pendulum clocks and
in designing a clock that would beat seconds and tell mean time as well
as sidereal time I used a gear train of 15/47x49/97x82/31/x87/37 as I
remem
Hi all,
I've just built a GPS-disciplined oscillator built around a 10544A, somewhat in
the style of the Brooks Shera unit, just to use around the shack. Problem is,
now that it's wired up, I notice the output is heavily distorted. It's clipped
on the negative side of the waveform, like an emi
Hi Brian:
Why? Do you just want to see the sidereal time on a display or do you
need a digital output?
The Spark Fun "serial enabled" displays use what's called a "back pack"
that has the PIC 16F88 uC and it's used to do serial data to LCD
parallel data can control lines. I've made some cloc
Looing at the schematics quickly, it looks like 1 MHz. There is a clock
failure circuit on that line.
-John
=
> Hi
>
> So now the question becomes: With only modest / reversible butchery,
> what's
> the slowest pulse train it will accept?
>
> 1 MHz is not to bad to generate. Som
Hi
So now the question becomes: With only modest / reversible butchery, what's
the slowest pulse train it will accept?
1 MHz is not to bad to generate. Something slower would still be easier with
a computer. If 1 ms accuracy is "good enough" then driving it with anything
over 10 KHz is kind of o
Hmm. This gives me an idea of what to do with my second Western Union
Self-Winding clock. I currently use a Soekris Net4501, modified in a
manner similar to John Ackerman's, driven by a Thunderbolt. I use one of
the GPIO pins to provide the hourly synchronization pulse to my clock. If
I adjust the
Hi
Ok, so NTP is indeed "good enough" for the application. Each millisecond
bumps you a half meter...
Grab a beater PC or Soekris board and write some code.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Lux, Jim (337C)
Sent: Fri
The external input triggers logic (via a selectable divider). It would
easily go +/- 50% in frequency.
Artek Media has the manual.
-John
=
> Hi
>
> There may be a gotcha.
>
> If that HP box has their standard time base in it, your idea isn't going
> to
> work. The normal HP approa
On 1/15/10 9:13 AM, "J. Forster" wrote:
> Heresy:
>
> Why do you really NEED super accurate siderial time? If you are using it
> to point a telescope, you only need it accurate enough to get the guide
> stars into the field. Remember, the atmosphere refracts kinda randomly.
>
> -John
>
> =
Heresy:
Why do you really NEED super accurate siderial time? If you are using it
to point a telescope, you only need it accurate enough to get the guide
stars into the field. Remember, the atmosphere refracts kinda randomly.
-John
===
> Hi
>
> Gee, there's an idea. Grab a TBolt an
True. At the observatory where I worked in the 70s there was a very
accurate pendulum clock with a contact that incremented the clocks in the
domes every siderial second.
-John
=
> Before the advent of automated telescopes that can point to an object of
> interest a
> wall clock d
What are the differences between the two GPSDOs referenced in the subject ?
While Internet is plenty of information on the 3816, the 3815 seems to be
rarely (if ever) referenced..
TNX
Alberto I2PHD
___
time-nuts mailing list -- time-nuts@febo.com
Hi all ,
i find some information about altitude given by a GPS.
The correction is contained in the sentence $GPGGA as follow:
**
Bonjour,
Si vous prenez la phrase NMEA $GPGGA d'un GPS vous aurez l'indication de
correction d'altitude( en rouge ci-dessous et soulign
Sure it is.. In observatories, for instance, they'll have a sidereal time
display, because that's what's important. You know that Sirius crosses a
N/S line at a particular sidereal time (or more correctly, isn't that the
right ascension.. When the body crosses the meridian)
On 1/15/10 2:07 AM, "
This is all quite interesting. 6 years ago, for the MER rovers, I cobbled
together a scheme to drive off-the-shelf 24hr electric clocks off a 3325A to
run on Mars time (which is slightly slower than Earth time). Same scheme
can be used for sidereal time, or to make an indicator that runs at varyi
Hi
There may be a gotcha.
If that HP box has their standard time base in it, your idea isn't going to
work. The normal HP approach is to lock a local oscillator up to the
incoming reference input. That way they can handle a bunch of different time
base inputs without much bother. Their standard V
Thanks for the feedback, and from Keith too. Strange. I have the same
Firefox version. I'm running XP SP3, but I doubt that would be the cause.
I have no idea what's causing the problem here. Obviously it's something
unique on my system. If I get time later, I may try turning off all
add-in pr
Hi
Gee, there's an idea. Grab a TBolt and a simple micro. Hook them up to
something like a Soekris and a big LED display. Network it up to get the latest
offsets. Toss in a bit of wire and software and you get very high accuracy
sidereal time.
If NTP is "good enough" you could dispense with t
We still use it at the observatory.
For example, my object of interest is up between 0h and 17h LMST and a quick
glance at the sideral clock let's me know where I am.
Jim
2010/1/15 Bruce Griffiths
> Before the advent of automated telescopes that can point to an object of
> interest a
> wall cl
Before the advent of automated telescopes that can point to an object of
interest a
wall clock displaying local sidereal time was commonly used to help
point a telescope
using setting circles and the known coordinates of the (astronomical)
object of interest.
Bruce
Steve Rooke wrote:
Hi Bria
Rex,
seems to run OK for me using XP and Firefox on a Toshiba laptop.
I'm not sure just what I should see, but I got the eclipse path and
the software lets me look at profiles for places that I specify.
Keith G Malcolm
VK1KM/VK2AEM
Message: 5
Date: Thu, 14 Jan 2010 23:50:15 -0800
From: Re
As usual this is another thing that only works in the exclusive clubs
of Windows and Mac users, Linux is the also ran (no Google Earth
plugin for Linux). And yes I could pop it up on my laptop but that's
doing something important and I don't want it to mess its knickers and
waste a lot of my work.
Hi Brian,
I really love this group, it appeals to the technophile inside me and
it's interesting to see the answers that are given.
You should have know that posting to a nuts group would mean you would
get lots of highly technical responses but frequently the questions
posed are not answered as
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