The following paper indicates how to optimise the voltage drops in
electrical leads for both cryogenic and other applications:
http://arxiv.org/pdf/cond-mat/0508697.pdf
Bruce
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On 28/06/2008, at 1:14 PM, Bruce Griffiths wrote:
Stainless is trickier to solder than constantan.
Welding may be preferable.
A hint for soft soldering stainless steel, iron, nickel, chromium,
copper, brass, nichrome etc. but not aluminium.
Apply a very small amount of phosphoric acid
This is a chicken vs egg sort of problem. When I took apart the oven
on my 5065A rubidium, it looked to me as though the enamel insulated
nichrome wire developed a short about 50% into the coil, and wiped out
the transistor. It also heated the rubidium lamp hot enough to reflow
the solder on its
Bruce Griffiths wrote:
The following paper indicates how to optimise the voltage drops in
electrical leads for both cryogenic and other applications:
http://arxiv.org/pdf/cond-mat/0508697.pdf
Bruce
Equation 4 in the above reference should be divided by e (electron charge).
The extension
Chuck Harris wrote:
This is a chicken vs egg sort of problem. When I took apart the oven
on my 5065A rubidium, it looked to me as though the enamel insulated
nichrome wire developed a short about 50% into the coil, and wiped out
the transistor. It also heated the rubidium lamp hot enough to
Bruce Griffiths wrote:
Chuck Harris wrote:
This is a chicken vs egg sort of problem. When I took apart the oven
on my 5065A rubidium, it looked to me as though the enamel insulated
nichrome wire developed a short about 50% into the coil, and wiped out
the transistor. It also heated the
The heater winding for my 5061A crystal oven doesn't seem to be bifilar
wound, but it's a little difficult to tell. Since the heater works, I
don't want to risk poking around too much. However, one lead comes in
at one end, the other lead is at the other end.
BTW, my oven failed
Having just gone through the process of finding, acquiring, and fixing
an HP 5061A, here are a few pointers for qualifying one for purchase.
The biggest problem you're likely to face is a beam tube that's at
end-of-life. If there is an electronics failure (like mine, read on),
these clocks are
-nuts] cesium clocks..
Having just gone through the process of finding, acquiring, and fixing
an HP 5061A, here are a few pointers for qualifying one for purchase.
The biggest problem you're likely to face is a beam tube that's at
end-of-life. If there is an electronics failure (like mine, read
you toss around the 'stupid' when discussing oscillator design.
Some folks still have a close relationship to those old 00105-6xxx
oscillators.
Dave
- Original Message -
From: wje [EMAIL PROTECTED]
To: time-nuts@febo.com
Sent: Friday, June 27, 2008 4:32 AM
Subject: [time-nuts
wje wrote:
Yes, but my comment is rather specific... my oscillator failed because
the heater pass transistor shorted.
This sent the oven heater into full-on. The overtemp sensor is far
removed from the heater. There's a ribbon cable between the driver board
and the temp bridge sensor board
In this case, the temp thermistor bridge is outside the oven cavity
itself. The cable only passes power and the already-processed bridge
delta to the heater power amp. So, there's no particular benefit from
having the cable stuck to the heater wrap. (at least, I think so; my
basic
wje wrote:
In this case, the temp thermistor bridge is outside the oven cavity
itself. The cable only passes power and the already-processed bridge
delta to the heater power amp. So, there's no particular benefit from
having the cable stuck to the heater wrap. (at least, I think
Hi Bruce,
You would have to be careful with your constantin wire as there is a
thermocouple
junction of 40 microvolts/K at each copper/constantin connection.
If the pairs of junctions are kept together thermally all cancels out.
Stainless steel is also very non-conductive of heat, but would have
Neville Michie wrote:
Hi Bruce,
You would have to be careful with your constantin wire as there is a
thermocouple
junction of 40 microvolts/K at each copper/constantin connection.
If the pairs of junctions are kept together thermally all cancels out.
Stainless steel is also very
Well... in fact, that's sort of the question I'm asking. if one does
search Ebay, what's an effective search term?
Leaving aside the $60 Nike Cesiums...
Were you aware that you can add terms in the search box preceded by a
negative sign to exclude items that match that? ie cesium -nike
OK.. if one wanted a cesium reference in one's garage (just because
it's something you should have.. that GPSDO depends on outside
influences, after all)
what's the typical budget for getting one of these beasts used, and
where does one find one (Ebay? A time-nuts subscriber in a back alley
Jim,
If you're searching Ebay, just make sure you don't accidentally buy a
Nike brand of shoe...
Jim Palfreyman
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Quoting Jim Palfreyman [EMAIL PROTECTED], on Thu 19 Jun 2008
09:27:12 PM PDT:
Jim,
If you're searching Ebay, just make sure you don't accidentally buy a
Nike brand of shoe...
Jim Palfreyman
Well... in fact, that's sort of the question I'm asking. if one does
search Ebay, what's an
] [mailto:[EMAIL PROTECTED]
Behalf Of Jim Lux
Sent: Thursday, June 19, 2008 9:44 PM
To: Discussion of precise time and frequency measurement; Jim Palfreyman
Cc: time-nuts@febo.com
Subject: Re: [time-nuts] cesium clocks..
Quoting Jim Palfreyman [EMAIL PROTECTED], on Thu 19 Jun 2008
09:27:12
In message: [EMAIL PROTECTED]
John Miles [EMAIL PROTECTED] writes:
: Maybe try
:
: hp (5071a,5061a,5061b)
:
: ... to start with.
:
: The 5071as seem more desirable but they're also usually more expensive, and
: (the really scary part, true of all of them): how do you tell how
First a little humor:
http://www.leapsecond.com/pages/atomic-tom/
There is an atomic clock experiment I've wanted to do
for years.
I assume many of you know that, according to Einstein's
special theory of relativity, clocks moving fast run slower.
Similarly, according to his general theory
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