From: Mark Sims [EMAIL PROTECTED]
Subject: Re: [time-nuts] Thunderbolt - temperature
Date: Fri, 11 Jul 2008 21:23:20 +
Message-ID: [EMAIL PROTECTED]
The temperature is the electronics temperature. When I put the cover on my
red-boxed unit, the temperature went up about 8 C. This would
Magnus Danielson wrote:
The temperature is the electronics temperature. When I put the cover on my
red-boxed unit, the temperature went up about 8 C. This would not have
happened if them temp was inside the thermostatically controlled oven.
The temperature in the oven would also
From: Bruce Griffiths [EMAIL PROTECTED]
Subject: Re: [time-nuts] Frequency divider design critique request
Date: Sat, 12 Jul 2008 12:11:03 +1200
Message-ID: [EMAIL PROTECTED]
Magnus Danielson wrote:
Why not? It basically solves a problem most of us has, and only a few tweaks
away and it
From: Richard (Rick) Karlquist [EMAIL PROTECTED]
Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay
Date: Fri, 11 Jul 2008 20:58:15 -0700
Message-ID: [EMAIL PROTECTED]
Well, the good news is (if you buy one of these) is that the worst
that can happen is that you unwrap all that 2nd oven
Magnus
Magnus
A minimalist approach for the 5MHz to 10MHz doubler could use a full
wave (diode, BJT or JFET) doubler followed by a series tuned 5MHz
shunt trap to minimise the 5MHz content in the output.
Actually, it depends on weither you would like to get a 10 MHz or not.
Another
Magnus Danielson wrote:
I keep wondering if not a passive oven (metal box, insulation, metal box)
would be sufficient. Worst case temperature change rates would be
significantly
reduced such that the oven loop can track it better. The remaining temperature
shift will be less. Basically acts
From: Bruce Griffiths [EMAIL PROTECTED]
Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay
Date: Sat, 12 Jul 2008 21:16:41 +1200
Message-ID: [EMAIL PROTECTED]
Hej Bruce,
A box with multilayer walls: insulator/metal/insulator/ metal etc does a
much better job of attenuating thermal
I suspect that the fluctuation is some sort of noise or software glitch (but
one of my systems is powered by a very nice linear supply so probably not power
related).
What is strange is the decay. If it was a noise glitch, one would expect it
to last one sample. But, it decays back to the
Magnus,
I keep wondering if not a passive oven (metal box,
insulation, metal box) would be sufficient. Worst case
temperature change rates would be significantly reduced such
that the oven loop can track it better. The remaining
temperature shift will be less. Basically acts like a
Hi all,
for an upcoming experiment I am looking for precise external
time reference, preferrably an atomic clock that I can hook
up to a computer running a Unix variant.
I should be able to read out the time with a low latency, e.g.
over PCI or PCI-e bus.
The time reference will serve me as a,
I keep wondering if not a passive oven (metal box, insulation, metal box)
would be sufficient.
Large metal reflectively lined thermos bottles are worth considering. You do
end up with a lot of long skinny circuit boards that way.
Peltier based thermoelectric cooler's from Big Box Stores can
From: Ulrich Bangert [EMAIL PROTECTED]
Subject: Re: [time-nuts] Double ovened 10811-60158 on ebay
Date: Sat, 12 Jul 2008 13:09:55 +0200
Message-ID: [EMAIL PROTECTED]
Ulrich,
I keep wondering if not a passive oven (metal box,
insulation, metal box) would be sufficient. Worst case
Marc,
...preferrably an atomic clock that I can hook
if you need the stability and precision of an atomic clock you will of
course not come around to REALLY use one!
However, for everything else I would do it like that: Generate a 14.318
MHz signal phase locked or DDS synthesized from the
In message [EMAIL PROTECTED], Marc Balmer writes:
I should be able to read out the time with a low latency, e.g.
over PCI or PCI-e bus.
Read my timecounter paper, find a cheap PCI-FPGA development board,
learn basic VHDL, enjoy :-)
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
[EMAIL
By having only one sensor, in the case of the double oven that is obviously
not true, but what I meant was that even with a double oven, you only have
one sensor near the components you try to regulate, the other sensor
regulates the outside temperature of the first oven.
Didier
-Original
Quoting Marc Balmer [EMAIL PROTECTED], on Sat 12 Jul 2008 04:55:08 AM PDT:
Hi all,
for an upcoming experiment I am looking for precise external
time reference, preferrably an atomic clock that I can hook
up to a computer running a Unix variant.
I should be able to read out the time with a
Hi all,
for an upcoming experiment I am looking for precise external
time reference, preferrably an atomic clock that I can hook
up to a computer running a Unix variant.
I should be able to read out the time with a low latency, e.g.
over PCI or PCI-e bus.
The time reference will serve
Remember that heat flow is proportional to the FOURTH power of the temperature
difference. Insulation is generally a linear function. The combination makes
thermal stabilization over even small ambient temperature ranges rather
problematic.
Didier Juges wrote:
The designers of the HP E1938 (which never went to full production) went
through pains to try and keep the gradient evenly distributed precisely for
that reason. My guess is that it you take the cover out from the E1938, you
will find a perfectly symmetrical layout
Timenuts,
In introductory texts regarding the FFT there is some mention of Fourier's
studies having had something to
do with heat transfer. Yet most of the FFT work I've been exposed to has to do
with decomposing signals
into component sinusoids, translating between time and frequency
Jim,
I see that the same vendor has a few more units for sale. He has also
included a picture that labels all the connections.
Ed
Message: 2
Date: Wed, 9 Jul 2008 12:10:52 +1000
From: Jim Palfreyman [EMAIL PROTECTED]
Subject: [time-nuts] Double ovened 10811-60158 on ebay
To:
Quoting Mark Sims [EMAIL PROTECTED], on Sat 12 Jul 2008 09:12:34 AM PDT:
Remember that heat flow is proportional to the FOURTH power of the
temperature difference.
Heat transferred by *radiation* goes as the 4th power. Heat
transfered by conduction goes linearly. Unless you're in a
Quoting Mark Amos [EMAIL PROTECTED], on Sat 12 Jul 2008 10:13:36 AM PDT:
Timenuts,
In introductory texts regarding the FFT there is some mention of
Fourier's studies having had something to
do with heat transfer. Yet most of the FFT work I've been exposed
to has to do with
I'm looking for 74ac164 and 74ac112 in SOIC (.15 wide) as the usual
suspects (Farnell and RS Components) don't seem to stock these in UK :-(
I found most of the other 74AC logic I want.
I'm also hunting 200 Ohm 0.25W 1206 case thick film resistors. I can buy a
reel of 5000 at about USD34 from
for an upcoming experiment I am looking for precise external time
reference, preferrably an atomic clock that I can hook up to a
computer running a Unix variant.
How good a clock do you want/expect?
If you are using a computer, you have a layer of jitter from things like
interrupts and
Hi Dave,
Try www.mouser.com who list both 74ac devices in SOIC and have them in stock.
Richard
I'm looking for 74ac164 and 74ac112 in SOIC (.15 wide) as the usual
suspects (Farnell and RS Components) don't seem to stock these in UK :-(
I found most of the other 74AC logic I want.
I'm also
An easy answer to :
I'm also hunting 200 Ohm 0.25W 1206 case thick film
resistors. I can buy a reel of 5000 at about USD34 from RS
Components, but don't really need quite
as many as that!!! 300 ohm don't seem any easier :-(
Yes, I know these aren't in the standard resistor sequence.
Hi Dave Rapid Electronics in Colchester do SMBs the eaiest way to get
200 ohms might be 2 by 100ohm in series..though it wont fit a ready made
1206 size pcb :-((
www.rapidelectronics.co.uk
or www.rapidonline.com is one they quote now I think both work.
I dont think you will get 74ACs there
I too am seeing them - four or five events during a 24 hour time period. Below
are 50 temp readings before and after an event.
32.82
32.82
32.82
32.82
32.82
32.82
32.82
32.82
32.82
32.83
32.92
32.91
32.90
32.89
32.89
32.88
32.87
32.87
32.87
32.86
32.86
32.85
32.85
32.85
32.85
32.84
32.84
32.84
Mark Sims wrote:
Remember that heat flow is proportional to the FOURTH power of the
temperature difference. Insulation is generally a linear function. The
combination makes thermal stabilization over even small ambient temperature
ranges rather problematic.
Nonsense.
The radiative
Bruce Griffiths wrote:
I was only thinking that maybe there ought to be a buffer from the input
to the rectifier, or else higher frequency energy will escape out
towards the
source. At least some isolation should be there.
If one uses a common base stage to drive the diode
Bruce Griffiths wrote:
Mark Sims wrote:
Remember that heat flow is proportional to the FOURTH power of the
temperature difference. Insulation is generally a linear function. The
combination makes thermal stabilization over even small ambient
temperature ranges rather problematic.
Rick Karlquist wrote:
Bruce Griffiths wrote:
Mark Sims wrote:
Remember that heat flow is proportional to the FOURTH power of the
temperature difference. Insulation is generally a linear function. The
combination makes thermal stabilization over even small ambient
temperature
Rick Karlquist wrote:
Bruce Griffiths wrote:
Mark Sims wrote:
Remember that heat flow is proportional to the FOURTH power of the
temperature difference. Insulation is generally a linear function. The
combination makes thermal stabilization over even small ambient
temperature
Firmware version 0.0.4 is usable and has been uploaded, read the details and
download the firmware from my Wiki page:
http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:gps_monitor
Some user interface (to select which information to display) would be nice.
2 lines of 16 characters is
35 matches
Mail list logo
