Bob Holmstrom wrote:
Food for thought.
I find it interesting that no one has suggested alternatives to
improving the performance of a pendulum clock other than controlling it
with a higher performance clock. If the goal is a better clock why not
attempt to understand the source of the errors
David C. Partridge wrote:
Jim,
It might appear on the 2nd user market sooner, but the odds are you
won't be able to either repair it or calibrate it as the manufacturer
will have been the only supplier of either of these services, and no
service manuals will exist.
But is this any different th
Steve Rooke wrote:
That seems to indicate these devices are running a version of embedded
Windows for them to get infected by a virus and I wonder why they need
such a sledgehammer internally.
Steve
PS. sorry for top-posting but that's the only way I can reply at the
moment (basic HTML Gmail).
Hal Murray wrote:
jim...@earthlink.net said:
But over the next few years, I suspect you'll see more and more of it
coming onto the surplus market. My fond hope is that my daughter will be
able to capitalize on it.
A friend had a fancy scope with an Etherenet. It got infected with the
viru
J. Forster wrote:
Probably yes.
There are also a number of lower cost instruments (just above consumer
grade)like HF-VHF VNAs that implement much of the smarts in a PC on the
market.
As to high end instruments w/ USB or Ethernet, I'm not so sure. The USA is
doing less and less hardware developm
J. Forster wrote:
I very much doubt that the majority on this list have major govenmental or
corporate funding and shop from the new Agilent catalog that just came in
the mail.
As a result, I'd guess almost all the commercial test gear in the
posession of listers is from 1970 to 2000. That says
J. Forster wrote:
".. more generic interface." ??
The vast majority of professional test equipment has GPIB. Virtually
anything else is an "also ran".
FWIW,
-John
these days, ethernet and USB are becoming more popular. My own
preference is Ethernet and I long for the day when I can ditc
J. Forster wrote:
E A Foucalt Pendulum is not about time! It's about motion in
inertial space.
are they not the same, underneath it all?
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Eugen Leitl wrote:
On Wed, Jul 21, 2010 at 10:40:48PM -0400, Bob Bownes wrote:
Silly me, I just realized you need to compensate for the change in
length with temperature.
You could use an Invar wire.
Some insight from a friend (a proto-timenut) who was thinking about
building a 1ppm free pe
J. Forster wrote:
The problem is straight forward, except for sensing the position of the
pendulum so the impulse is applied at the correct phase.
There must be a bunch of published designs, but if I were to try it, I'd
use something optical or capacitive.
For optical, I'd put a annular ring of
Morris Odell wrote:
Hi all,
I have been asked to help with the construction of a Foucault pendulum. This
is a long pendulum which oscillates in a slow stately fashion in a fixed
plane which appears to move as the earth rotates. In reality the surrounding
environment is really moving relative to
Luis Cupido wrote:
Jim,
The implementation I've done on "reflock II"
(on a MAXII CPLD form Altera
http://www.qsl.net/ct1dmk/reflock.html )
Had fast aqs time in mind(*).
It captures in few 1pps pulses
and could stabilize to about 1% of dac range
in quite less then 60s.
How slower you need it to
Is there some (inexpensive) GPSDO that has a "time from power on in an
unknown location to reasonably stable" in the <5 minute category?
Frequency accuracy in the 1E-9 range would be fine.
A regular old GPS has a Time to First Fix well under that, and it should
be cranking out 1pps pulses with
EB4APL wrote:
A word of caution here: Don't trust Google maps coordinates for any
technical / serious work, they can have errors in the 100´s meter
class. And also don't use the copyright date of the maps and images as
a time reference, they normally are older than that. If you live in an
a
Bob Camp wrote:
Hi
From a quick look it's not real clear how you would go about extracting time from the software suite. It's certainly useful for navigation though.
A secondary gotcha is that the TBolt likely has some internal "issues" that
distort the data a bit. Running a TBolt on both en
Bob Camp wrote:
Hi
I just got through poking at a couple of TBolts with Lady Heather. It appears that you can indeed get the hardware and software to put the TBolt into single satellite mode. That may enable a pretty simple GPS common view setup.
One way to do it:
Somebody picks a set of sat
Steve Rooke wrote:
On 5 July 2010 06:10, J. Forster wrote:
Why stop there? How about buying Russian Hydrogen MASERs and putting them
in hand-rubbed old growth teak boxes and selling them for $995,000?
They are pulling out 14,500 y/o kauri trees (hard wood) out of peat
bogs over here which are
Michael Baker wrote:
Time-Nutters--
The 5-year Flash Density Map of the USA provided by
the National Weather Service indicates that my county
here in N. Central Florida experiences "16 and up"
strikes/sq-km/year.
< http://www.weather.gov/os/lightning/images/map.pdf >
Experience bears this out.
Hal Murray wrote:
or with a pair of current output DACs and a resistive divider/summer so you
have a "high order" and "low order" voltage.
If it were that simple, the manufacturers would package it up into a single
chip. :)
And they do... hence delta sigma designs..
Back in the good old d
Bruce Griffiths wrote:
Attila Kinali wrote:
Moin,
On Sat, 26 Jun 2010 21:14:02 EDT
ewkeh...@aol.com wrote:
What you want is basically a Shera Board. That design has been around
for
quite some time and has served me very well.
Yes. The Shera Board and similar designs serve as an exa
erniepe...@aol.com wrote:
HI Julien,
Do you have a detailed info, docu about the TrueTime XL-DC??
I have 2ea of this unit and one is not going to lock...
Any experience or help appreciated.
Rgds Ernie.
There's a fair amount of info on the XL-DC on the web. I assume your
problem is
Didier Juges wrote:
I am not sure how to translate the IMD specs into integral or
differential non-linearity, but from what I have seen, IMD specs are
not significantly better for 24 bit sound cards than for the older
high-end 16 bit models, when high-end 16 bit models were available.
Noise specs
Didier Juges wrote:
I can only guess at what a sound card with linearity specs
approaching those of the AD kit would cost, and it's still AC
coupled, and as Poul pointed out, has no long term stability spec.
This *is* an issue.. the audio ADCs have great performance in the "sub 1
second" sort
Didier Juges wrote:
Steve,
You may want to check the "Analog Devices MiniKit for ADuC702x-series".
http://www.google.com/search?q=Analog+Devices+MiniKit+for+ADuC702x-series
This kit includes a 24 bit ADC and integrated ARM processor in a small PWB with
all the tools and sample code to do what
Steve Rooke wrote:
The eval board for the part may have a computer interface built into it.
So I need to locate this if possible, any pointer please?
Go to Analog Devices website (http://www.analog.com/) and find your
ADC.. typically there's an eval board with a USB interface available.
Fo
J.D. Bakker wrote:
I wonder if anyone has done something like this before and could share
their experiences.
The general principle should work. However, as you're interested in slow
changes, there are some error sources that might be unacceptable,
including the drift of (differential) channel
Robert Benward wrote:
Bob
Boy, you guys are really making me read a lot. I'm digesting Wiki right
now.
I see tau, but does identifying a tau of 1E-14 allow you to say you are
locked to 10fs? The smallest tau I've seen in my E1938 collection is 1E-1.
Bob
tau is the time over which the
Robert Benward wrote:
Rated for 1400V from CENTER conductor to shield, not shield to the
outside. If you choose to use RG-58 with 250V on the shield then you
will need to put the entire cable inside conduit. It is not acceptable
to have any type of exposed mounting.
Bob
Yeah... I've been
Robert Benward wrote:
I don't think the shield is rated for +/-250V, and I'm not sure I would
want to handle RG-58 with 250V on the shield.If you do this, use
triax cable and ground the outter shield, and make sure the breaker can
interrupt the fault current (if the fault currrent is in the
Robert Benward wrote:
Yuri,
Another suggestion would be to look for a low power GPS; I can't image
with all the GPSs out there in all those cell phones, that they all take
40mA or more. If you find one that does have low power, then locate it
at the antenna and then you won't need an active a
Glenn Little WB4UIV wrote:
I do not know why the manufacturers insist on gold plating leads that
are designed to be soldered.
Silver plating seems like a better solution.
In this case, it appears that pins were soldered that were not designed
to be soldered.
gold does not tarnish, silver d
Hal Murray wrote:
[Chile quake]
Graph of position (3 meters!):
http://ivsopar.obspm.fr/earth/tigo
3 meters in one direction and 60 in another.
Just to make sure we are all on the right track, the scale on the graph is
cm, so the motion was 300 cm West and 60 cm South.
I may have
Magnus Danielson wrote:
On 06/12/2010 03:36 PM, jimlux wrote:
While it would be fun to know, the practical impact of such a change is
very, very small, to the level of being ignored. Considering of a major
event actually consisting of many hundreds of earth quakes spread over a
rather
Magnus Danielson wrote:
On 06/12/2010 02:33 AM, Hal Murray wrote:
jim...@earthlink.net said:
The Chilean earthquake changed the angular rotation rate (or,
probably more
accurately, changed the direction of the axis of rotation as well)
of the earth a small amount, as do most large earthquake
Hal Murray wrote:
jim...@earthlink.net said:
The Chilean earthquake changed the angular rotation rate (or, probably more
accurately, changed the direction of the axis of rotation as well)
of the earth a small amount, as do most large earthquakes.
Has anybody measured that?
I don't think y
Hal Murray wrote:
iov...@inwind.it said:
I was wondering, why we assume that Earth's rotation is slowing down,
instead that clocks are speeding up?
The quick answer is that there is a mechanism that explains why the Earth is
slowing down: tidal effects. There is no corresponding way to ex
Tom Van Baak wrote:
Whether the answer is (a) or (b) doesn't change the fact that
the earth day is a poor clock compared with other clocks now
available. Besides tidal friction effects which might be hard to
imagine, or lunar effects which you already know about, note
that every time it rains or
Ulrich Bangert wrote:
Jim,
pardon if I correct you: The reciprocal counters were an intermediate thing
between the counting only and the subclock interpolating ones. A reciprocal
counter would notice when a frequency measurement would be too imprecise due
to an arkward relationship between that
Ulrich Bangert wrote:
The next improvement to the old fashioned pure counter was the invention of
subclock interpolation schemes. A counter using this works so: After the
beginning of the gate time it waits of the next zero crossing and then
measures the time up to the last zero crossing wi
Giuseppe Marullo wrote:
>If it is, why not purchase an *analog* DCF77 synchronized clock, set
it to local radio time and then just move the hands on the spindle to
reflect UTC? That's what I did with my WWV clocks that only handle the
US time zones. >Worked just fine.
Well, I could just buy a
Magnus Danielson wrote:
Also, modern cheap programmable TCXOs break the model as they have a
hump in the phase noise due to their locked PLL, which the original
model does not allow for. The autocorrelation function will be quite
different. Notice how this ripples over to other locked oscill
You can, of course, now get 12 bit digitizer PCI cards for your
PC.
Or heck, eval boards for 12 bit ADCs that have USB interfaces..
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J. Forster wrote:
VNAs are very expensive toys. I have an HP 8753 and was just outbid on a 6
GHz source assembly. :((
Mine has a very complex multi-chip RF Hybrid that has a partial failure,
so it only goes to 3 GHz. That's a serious problem with modern high-end
microwave gear, if anything dies
Richard (Rick) Karlquist wrote:
We have a bunch of sweepers at work, and many of the them have
died and can't be fixed. The only way they can be repaired is
to cannibalize one to fix another, assuming they don't have
the same bad module. We have given away an 8510 to a school
and have others ga
Steve Rooke wrote:
Just noticed there is a flood of lower end priced (<$5k & <<$5k) VNAs
on FleeBay just in case anyone is looking for one. No need to thank
me, just buy me one as well :)
Steve
Interesting... be aware that a lot of those 8510s aren't the whole
analyzer, just the display or R
Poul-Henning Kamp wrote:
In message , Jim
Palfreyman writes:
I have timed the accuracy of this internal clock and have found it to be
pretty good so far. 17 days ago it was ticking over at 21.8 sec past the
minute and a quick visual inspection today and it was still *very* close to
that. I wil
Bob Camp wrote:
Hi
Strange as it seems, *stocking* the R's and C's can be an issue. There's also placement cost. Based on some of the numbers you see, the cross over point (IC to odd value R's and C's) is amazingly low. I'm not saying any of that's right, just that it's the way a lot of companie
Magnus Danielson wrote:
On 05/26/2010 01:09 AM, Bob Camp wrote:
Hi
Like all the rest of us I'm making assumptions. I *assume* that we're
talking about an implementation that will handle IRIG over audio over
a fairly wide dynamic range.
Well, like most cases, I'd assume it is over "sufficien
Hal Murray wrote:
The IRIG-B decoder work I did was implemented on power systems relays &
disturbance recorders several years ago, then I left the company and in the
meantime, they changed over to an FPGA implementation and skipped the
processor altogether. Now I'm back with that same company (a
Bob Camp wrote:
Hi
Audio codecs (especially monophonic ones) are pretty cheap these days.
Depending on volume they can get to the sub $1 range. Even in small quantity
they are below $4. That makes them a pretty tempting "front end" for a send
/ receive box.
Bob
i would think, given that the
Stanley Reynolds wrote:
Example of IRIG-B generator and decoder implemented in LabVIEW FPGA:
http://zone.ni.com/devzone/cda/epd/p/id/3396
Thanks,
I was looking for something in VHDL or Verilog... I'm not sure how well
the Labview RIO, etc. stuff ports to non-Labview environments, but I'll
Hal Murray wrote:
Can anyone help with a modern IRIG B chipset manufacturer
Send or receive?
The ntp package has software for both sides using PC audio cards.
I've been looking for an open-source IRIG B or E reader for FPGA use.
___
time-nuts mai
Clive Green wrote:
Can anyone help with a modern IRIG B chipset manufacturer
I didn't know that there was such a thing, even in ancient times, much
less modern. All I've seen are designs made of discretes or programmed
in a microcontroller or FPGA.
Are you looking for a IRIG generator or
Bob Camp wrote:
Hi
Gotta label them *something* or sorting through them in the cable bin becomes pretty difficult.
In addition to the wiring options you can (obviously) have either a male or female on
either end. There are so many "odd" pieces of gear out there that you can have
pretty much
Stanley Reynolds wrote:
Dec computers / terminal servers were as I described, but many brands
were different. Still have a BOB aka break out box with LEDs to
indicate levels, matching transmit and receive is easy, getting the
hardware flow control / signaling right was a little more diffic
Robert Benward wrote:
Bob
Looking at al these pictures, I'm beginning to think I have a Z3801A,
not a 05A. After a few hours, the unit still has not locked. It is
possible the antenna is bad. I have a few more that I know are working.
I also took the precaution of connecting an antenna bef
Bob Camp wrote:
Hi
The Symmetricom 3805's have an area on the lower board right behind
the "control" DB-25. It's very similar to the 3801. There are three
rows of holes for 0.025" post connectors. One row pair is labeled
RS-232. The other row pair is labeled RS-422. The original intent
appears t
Mike S wrote:
At 09:47 PM 5/22/2010, Robert Darlington wrote...
Was there ever a standard? I always thought the "RS" stood for
Recommended Standard, as in "you *should* do the following" as
Recommended Standard, and is "this is a standard which is recommended
for use."
The latest standard
Rex wrote:
Sorry about the empty post -- hit the send key by accident.
Ulrich's free Z38XX program works great as a monitor for the Z3805. He
added some stuff to specifically support differences from a Z3801. The
Z3801 programs can be used but can't support the extra satellites the
3805 can t
Eugen Leitl wrote:
On Wed, May 12, 2010 at 06:03:11AM -0700, jimlux wrote:
Allan had a paper where he had 8 inexpensive crystals coupled with
mixers and a microcontroller. I think it's called the Clever
Temperature Compensated XO or something like that.
Presumably, a large populati
Bob Camp wrote:
Hi
The tendency of clocks to self synchronize dates back at least to the
days of pendulum clocks. It may date to the era of water clocks, but
if so it's undocumented. It has been observed on a wide range of
modern clock designs. If you look into "injection locking" you'll get
a p
Eugen Leitl wrote:
Has anyone utilized a network of locally, weakly coupled
oscillator synchronization (a la
http://www.projectcomputing.com/resources/sync/index.html )
for precise timekeeping purposes?
There was a discussion on this list about doing something like filling a
cavern with pendul
Nick Foster wrote:
If you're thinking about using a CPLD to load registers in a PLL chip, why not
just implement the PLL on the CPLD? After all, if you're looking for
simpler-is-better, there's not much on a dedicated PLL chip that you can't
easily replicate in CPLD with some care and attentio
Luis Cupido wrote:
Hi,
I'm looking for a relatively simple PLL chip
like LMX1501 or similar.
I mean, looking for a new design, that is something
that is easy to source (known to be in production etc)
recent/modern enough to provide a low phase noise.
Is for VHF/UHF below 500MHz application and
Luis Cupido wrote:
Hi,
I'm looking for a relatively simple PLL chip
like LMX1501 or similar.
I mean, looking for a new design, that is something
that is easy to source (known to be in production etc)
recent/modern enough to provide a low phase noise.
Is for VHF/UHF below 500MHz application and
Hal Murray wrote:
bruce.griffi...@xtra.co.nz said:
If there is no electronic tuning available one can use a DDS based
synthesiser to produce a corrected output frequency. However close in spurs
will be problematic unless one use a couple of simple mix and divide stages
or resorts to a Diophanti
life speed wrote:
Time Nuts;
I have a customer request for a microwave frequency synthesizer with
extreme accuracy requirements; 4 X 10^-11, or 0.04 PPB. Obviously
this is way out of quartz oscillator territory. Is GPS 1
pulse-per-second useable, or do they need an atomic clock? Maybe
they do
Bob Camp wrote:
Hi
The ua723 obviously is the one destined to outlive the cockroaches. The
linear power supply industry still seems to consider them "state of the
art".
Bob
Like the 555, it has a nice combination of function and predictability.
It's in that "good enough" category.
_
Arthur Dent wrote:
jimlux-"And you can probably still buy 709 and 714 op-amps.."
I'm old enough to know that it is 741 op-amps, not 714. ;-)
Ooops..
it was early in the morning
And for the life of me, I cannot remember the number of the comparator
in the 7xx series.. conte
Rob Kimberley wrote:
Am I really that old?!!?
:-)
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Chuck Harris
Sent: 19 April 2010 10:10 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] lunatic frin
Chuck Harris wrote:
Are they really? For some reason, every Trinitron I have ever seen
has clusters of little stick on magnets placed here and there on the
back of the glass envelope.
The trinitron has a shadowmask. It is a grill of highly tensioned wires
that are positioned just behind the sc
Chuck Harris wrote:
David Martindale wrote:
However, I don't see how the earth's tilted field prevents a CRT from
being
used in both hemispheres. I can see how it might need to be realigned,
since it uses permanent magnets on the yoke and their field will be
influenced by the earth's local f
wa1...@att.net wrote:
FWIW.A good high quality compass needs to be designed based on what
region of the earth you plan to use it in. The Suunto ones I have are
marked with a US region code.
That's because they need to compensate for the "dip" in the magnetic
field. The south end of th
Bob Camp wrote:
Hi
The only real limit on a Johnson counter is how clever you get making sure
that only one stage is a 1 and all the rest are zeros. There are *lots* of
ways to take care of that, each with it's own set of trade offs.
Bob
Of course, if your goal is "minimizing gates" or "mi
Bob Camp wrote:
Hi
The only real limit on a Johnson counter is how clever you get making sure
that only one stage is a 1 and all the rest are zeros. There are *lots* of
ways to take care of that, each with it's own set of trade offs.
One problem with a Johnson counter is that it takes many m
Eugen Leitl wrote:
Hi -- a couple somewhat lunatic questions. Figured this would
be the best place to ask.
Anyone aware of a time standard which compensates in regards
to an ideal flat-spacetime-at-rest-relatively-to-cosmic-background
reference clock? I realize this is not relevant for any affor
Bob Camp wrote:
Hi
There have *always* been multiple tiers to the surplus market.
Catalogs of gear have always shown up with prices that were 10X (or
100X) what an item might be bought for. That was as true in 1965 as
it is today. A *lot* of those old time outfits lived off of a buy it
for < 1/3
saidj...@aol.com wrote:
Back in the days (around 1985 or so) Caltech in Pasadena used to have a
surplus store on campus. I spent a good time in that store, and still have
some of those treasures. Lot's of JPL stuff.
Does anyone know if that still exists??
No. doesn't exist.
Most govern
Rex wrote:
jimlux wrote:
Scott Burris wrote:
C&H closed briefly to move and is now open in Duarte:
http://www.candhsurplus.com/
At Apex, a friend tried to purchase a nose cone from a rocket, but
they declined
to sell it to him because they were making too much money renting it
out to m
Scott Burris wrote:
C&H closed briefly to move and is now open in Duarte:
http://www.candhsurplus.com/
At Apex, a friend tried to purchase a nose cone from a rocket, but they declined
to sell it to him because they were making too much money renting it out to
movie studios.
Scott
That is
Dave Baxter wrote:
This might interest you
http://www.members.shaw.ca/swstuff/gpsreference.html
These people can cal' it, they say.
http://www.raelectrical.com/services/anritsu-2.htm
There are several other hits, including other people who stock used
items.
Amazing what you find when you g
John Allen wrote:
A few notes about the connector.
First, I hate BNC connectors.
But the BNC is useable to 11 GHz (No vswr spec.), and has a VSWR spec. of 1.3:1
up to 4 GHz. (See link below, about half way down the page.)
http://www.amphenolrf.com/products/bnc.asp?N=0&sid=4BAAA780568BE17F&;
T
Jeffrey Pawlan wrote:
On Thu, 25 Mar 2010, Magnus Danielson wrote:
Dear Raj,
Oh, sorry, needed a few extra. Wanted to recover the rubidiums and put
some on Ebay.
I gave a lecture about antennas for operation on 1296MHz last week and
mentioned that my vacuum tube power abplifier was damage
mike cook wrote:
Yes Bruce, I also think that azimuth dependent masking would be useful.
I have been suffering from strong reflections from facing buildings at
50m to 100m, which cause sharp departures from the average PPS TI
While telling the nav algorithms inside the box would be the most
Bruce Griffiths wrote:
Mike
Perhaps a single antenna element from the phased array in the following
JPL paper would be useful:
http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/12178/1/01-0082.pdf
I don't know that Mark's antenna is the right kind of thing for GPS.
the x-pol off axis is pr
Bob Camp wrote:
Hi
I certainly won't disagree with the data. I have noticed over the years that past a few MHz antennas out in the fresh air always seem to work better than indoor antennas. It could easily be that there is a *lot* of water in your typical roof. Certainly the water is far from pu
Don Latham wrote:
hello the group:
I've just installed a new "mercury-free" thermostat in my shop. I looked
the thing over and realized it has everything needed to control a
"constant temperature" enclosure. There's a diode used as temp sensor,easy
to remote with two wires, a place to put two AA
Bob Camp wrote:
Hi
Machining a chunk of Plexiglas sounds like more trouble that I would want to go to for a cheap choke ring setup.
Maybe a hemispherical Plexiglass serving bowl
take a look at inexpensive light fixtures with hemispherical or
spherical plastic globes.
Actually, hemi
David C. Partridge wrote:
definition of "pie"
3.1415926535 etc ?
Ooops
D.
And, as my daughter reminds me, today is pi day (in the U.S. where we
write the date month/year.. those of you in the rest of the world will
have to wait a long time, as there is no April 31st)
_
Predrag Dukic wrote:
How well depleted it really is?
DU has about 1/3 the U235 of natural U, of which less than 1% is U235.
All the isotopes are radioactive, but I don't recall what the relative
activities are. I think U238 has a half live of 4E9 years or more, so
not very many atoms s
J. Forster wrote:
If you like starting from scratch, get a copy of "Procedures in
Experimental Physics" by John Strong.
-John
And, relevant to the thermal time constant discussion.. That book has a
great section on thermal diffusion and conductivity, along with a chart
of material properti
Bob Camp wrote:
My personal experience suggests that setting one up is indeed a black art known
only to the select few. The high priest takes them into the back room and they
magically come return in working order several days / weeks / what ever later.
High priest goes on vacation - not muc
Bob Camp wrote:
Hi
The gotcha is that you are interested in the amount of heat per cubic foot rather than the amount of heat per pound. You need to take the standard heat per weight numbers and convert them to heat per volume numbers.
Of the things you can easily get, copper is good. Steel is
Brooke Clarke wrote:
Hi Bruce:
If a square meter of Styrofoam is 1.5 deg C/W then a cubic inch would be
39.37 * 39.37 * 1.5 or 2,325 deg C/W
The DS3231 dissipates about 1 mw when running. I'm not sure how to come
up with an allowable temp increase, but suspect it's based on not
exceeding t
Hal Murray wrote:
This, and similar impressive accomplishments, has prompted some
lunchtime discussion at work (JPL).. One of us (N5BF) has been
contemplating what it would take to do an amateur EarthVenusEarth
(after some of his experiments doing EME with 5 watts)..
Perhaps a better question
Brooke Clarke wrote:
Hi Bruce:
What does m2K/W mean? See:
http://building.dow.com/europe/uk/proddata/styrofoam/thermal.htm
50 mm it's about 1.5 and for 100 mm it's about 3.
thermal resistance (you can tell because it's degrees/watt, as opposed
to watts/degree which would be conductivity)
Paul Boven wrote:
Hi Tom, everyone,
Tom Van Baak wrote:
See: http://www.leapsecond.com/museum/pulsar for some
pulsar ADEV stability plots and links to many research papers
with all the details.
Your page starts with the question "if it was possible for an amateur to
receive pulsar signals?".
Bob Camp wrote:
Hi
Sure never seen any of them on any gear in my junk pile.
I also never seen a customer ask for them as an output connector on an
oscillator. I wonder how common they actually are.
Bob
On Feb 27, 2010, at 9:59 PM, Bruce Griffiths wrote:
Actually there are miniature twinax
Mike Feher wrote:
In general, what about the old National "damn fast" and super damn fast"
LH0032 & LH0033? I used to use a lot of those in my designs many years ago.
- Mike
Gotta really decouple the power supplies on those puppies...
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