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 defi
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
>>>
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
>>>
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.
>>
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 d
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 radi
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
3
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 th
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 sequen
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'
> 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 c
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 R
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 dec
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
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: time
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 domain,
On 12 Jul 2008 at 16:12, Mark Sims wrote:
>
> Remember that heat flow is proportional to the FOURTH power of the
> temperature difference.
This is Stefan's Law - it applies only to radiation.
Heat transfer by conduction and convection are linearly proportional to
temperature difference.
C
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 ar
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.
___
> 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 w
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
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
My understanding of thermal regulation is that one of the more difficult
thing to do is precisely to know what is the temperature of the components
you are trying to stabilize.
If you have one oven (even double oven), you have one temperature sensor.
The best you can do is keep the sensor at a con
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
[EM
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
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
>
> 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
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, w
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 l
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 o
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 therma
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
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
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 2
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
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 woul
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
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