Can you take some photographs ? It would be intersting to see it. It
sounds like some dipoles with phasing lines under them possibly.
Bruce's call of quadrifilar helix antenna matches what I found via google.
I didn't get a good shot looking down inside the cylinder. Here is the
outside
2009/8/15 steve heidmann steveheidm...@yahoo.com:
Hi Burt ,
Two thousand years ago the Wobulator was invented . An early sweep generator !
Was that one of the first miracles?
73,
Steve
Steve
--- On Fri, 8/14/09, Burt I. Weiner b...@att.net
When applied to meter movements this is called geotropism.
Robert G8RPI
--- On Fri, 14/8/09, Magnus Danielson mag...@rubidium.dyndns.org wrote:
From: Magnus Danielson mag...@rubidium.dyndns.org
Subject: Re: [time-nuts] Gravity and OCXOs
To: Discussion of precise time and frequency
Joseph M Gwinn wrote:
Bob,
time-nuts-boun...@febo.com wrote on 08/14/2009 01:05:34 PM:
From:
Robert Darlington rdarling...@gmail.com
To:
Discussion of precise time and frequency measurement
time-nuts@febo.com
Date:
08/14/2009 02:06 PM
Subject:
Re: [time-nuts] Difference in GPS
Bruce Griffiths wrote:
Hal Murray wrote:
My Panasonic VIC100 antenna had a few screws to hold the bottom to the
plastic cone top. The bottom had an o-ring seal that stuck a little
but was still pretty easy to slide the bottom from the top half.
Inside was a patch antenna on top of a pcb.
On 8/15/09 7:58 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
Thats a quadrifilar helix antenna.
A quite traditional antenna form.
Not sure I have one of those around here.
If you're near a harbor with fishing boats, you'll see plenty of quad
helices about a half a
Lux, Jim (337C) wrote:
On 8/15/09 7:58 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
Thats a quadrifilar helix antenna.
A quite traditional antenna form.
Not sure I have one of those around here.
If you're near a harbor with fishing boats, you'll see plenty of quad
helices
When possible, the thing I do to eliminate the effect of small gravitational
changes or tilt
from effecting the Freq of my Oscillators, is to orientate their case so that
the osc is approximately at its MAXIMUM 2G turn over axes.
This gives the osc a null to small gravitational changes, much
Hi Warren,
that's a smart idea.
It's fun to try different OCXO types out for their individual
sensitivities. I have seen some that are only sensitive in one single axis,
others that
react on several axie.
To take your concept further, one could also orient the OCXO to minimize
the
Although we time-nuts prize quartz oscillators that are highly-stable
and well-insulated from environmental effects there is an entire
industry doing the exact opposite -- using quartz as a sensor.
Some of the best thermometers are based on quartz oscillators
(hp 2804A) cut to maximize, rather
And billions of accelerometers (from air bag sensors to Wii game
controllers to the iPod touch and iPhone) have been produced in
the past decade. Google words like MEMS Quartz Accelerometer.
Also for Quartz Rate Sensor QRS.
I'm not so sure they use quartz. The ones I've seen are micromachined
saidj...@aol.com wrote:
If I read the post correctly, someone said they can literally talk to
their DRO, and make the voice come out of their Spectrum Analyzers FM
demodulation loudspeaker. After all, crystals are quite microphonic as
well.
bye,
Said
A well used trick with the HP608
One of my side jobs is to produce better than state of the art ultrasound
transducers. That being said, there is nothing particularly better about
mine other than when I say it's a 1MHz transducer, I really mean 1.0Mhz,
not 980kHz, not 1.2Mhz. The way I achieve this is to lay down gold, a
Hi Bob,
Why do they have to be so precise ? And what are they being used for ?
BillWB6BNQ
Robert Darlington wrote:
One of my side jobs is to produce better than state of the art ultrasound
transducers. That being said, there is nothing particularly better about
mine other than when I
Real time monitoring of the objective is a good way to go. I don't thing
making semiconductor or mirors is as critical, hence a chamber monitor
suffices.
-John
==
One of my side jobs is to produce better than state of the art ultrasound
transducers. That being said, there is nothing
I was basically doing the same thing with another type of sensor, but plated
on the gold and then etched it away until joy was maximized...
The way I achieve this is to lay down gold, a few
atoms at a time, and track a resonance peak (network analyzer
Anybody know where I can find a PDF of the HP 5065A rubidium frequency
standard ?
Brian Kirby KD4FM
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and follow the
Another nifty application of the effect is the resonant beam balance.
Basically it can weigh things at the molecular level by measuring the change in
frequency of a vibrating quartz or silicon beam... it can be tricky getting
and keeping your sample on the scale...
On 8/15/09 8:27 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
If you're near a harbor with fishing boats, you'll see plenty of quad
helices about a half a meter in overall height, used for VHF Weather
satellite reception. They're also used on spacecraft (Mars Science Lander,
Robert Darlington wrote:
not 980kHz, not 1.2Mhz. The way I achieve this is to lay down gold, a few
atoms at a time, and track a resonance peak (network analyzer and some
simple code in VB of all things). We actually drive the transducer as we
sputter coat the gold on top and can see the
On 8/15/09 11:32 AM, saidj...@aol.com saidj...@aol.com wrote:
Hi Warren,
that's a smart idea.
It's fun to try different OCXO types out for their individual
sensitivities. I have seen some that are only sensitive in one single axis,
others that
react on several axie.
To take your
I don't know. I'm just the lab tech! I cater to national labs, in
particular LANL which is right down the street from me. I've been involved
with the guy that developed SFAI (swept frequency acoustic interferometry).
We use this technique to fingerprint and characterize various substances
J. Forster escribió:
As you feel your heart beat, google for Quartz Pressure Sensor
Again, I think these are semiconductor sensors.
Yes, but there are also quartz pressure sensors. Long time ago I used a
equipment to measure water columns (and hence sea waves height) that
used a
Oh, I know there are quartz transducers like accelerometers, pressure and
force gages, etc. from companies like Endevco, Kiag/Krystal, and others.
But in my experience they are lab instruments costing a bundle.
The airbag sensors are cheap... likely a buck or twp. Hence the use of
silicon.
Brian Kirby wrote:
Anybody know where I can find a PDF of the HP 5065A rubidium frequency
standard ?
Brian, assuming you mean the manual, Artek Media have one for sale, but
it is for the older versions. I have never been able to find one for
the later versions that use the 10811 OCXO.
Dan
Brian Kirby wrote:
Anybody know where I can find a PDF of the HP 5065A rubidium frequency
standard ?
Brian Kirby KD4FM
There's one in the manuals section of Didier's site.
Bruce
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To unsubscribe,
Yes... it was not cheap, exactly :) It was from this company:
http://www.paroscientific.com/
Regards,
Javier
J. Forster escribió:
Oh, I know there are quartz transducers like accelerometers, pressure and
force gages, etc. from companies like Endevco, Kiag/Krystal, and others.
But in my
We used an Rb magnetometer to measure total charge change due to lightning
in 1964 or thereabout-
Don Latham
Tom Van Baak
Although we time-nuts prize quartz oscillators that are highly-stable
and well-insulated from environmental effects there is an entire
industry doing the exact opposite --
Do you mean a quartz manometer? If so, those are many, many kilobucks.
They don't use a quartz crystal, however.
They are Bourdon Tube technology, at least the TI ones are. There is a
helix of fused quartz tubing, like a spiral condensor you'd see in a
chemistry lab, inside a jar. There is a
As I recall, this is the type of antenna my handheld GPSr has. I had a set of
batteries bleed out in and had to disassemble it in order to do a good
cleaning.
-Dave
- Original Message -
From: Magnus Danielson mag...@rubidium.dyndns.org
To: Discussion of precise time and frequency
Mine is the 10811-60109.serial number prefix is 2432.
Bought the unit at The Huntsville Hamfest today. I knew the test
equipment dealer and he let me take the unit home to check it and so far
it appears to be OK. I had to adjust the coarse frequency before I
closed the loop, as it
Lux, Jim (337C) wrote:
On 8/15/09 8:27 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
If you're near a harbor with fishing boats, you'll see plenty of quad
helices about a half a meter in overall height, used for VHF Weather
satellite reception. They're also used on spacecraft
Oops. It looks like they sense the force from the Bourdon tube, rather
than the displacement.
-John
===
Yes... it was not cheap, exactly :) It was from this company:
http://www.paroscientific.com/
Regards,
Javier
J. Forster escribió:
Oh, I know there are quartz
On 8/15/09 3:25 PM, Chuck Harris cfhar...@erols.com wrote:
Lux, Jim (337C) wrote:
On 8/15/09 8:27 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
If you're near a harbor with fishing boats, you'll see plenty of quad
helices about a half a meter in overall height, used for
On Sat, Aug 15, 2009 at 03:34:29PM -0700, Lux, Jim (337C) wrote:
Haven't all of the VHF weather satellites been decommissioned?
Could be. I suspect that those antennas have been up on those boats for
decades.
Hardly, there are still the old analog APT satellites in operation
plus
Lux, Jim (337C) wrote:
On 8/15/09 3:25 PM, Chuck Harris cfhar...@erols.com wrote:
Lux, Jim (337C) wrote:
On 8/15/09 8:27 AM, Magnus Danielson mag...@rubidium.dyndns.org wrote:
If you're near a harbor with fishing boats, you'll see plenty of quad
helices about a half a meter in overall
Yes, using a quartz resonator to sense the force and other to provide
temperature compensation. I remember that it was a very sensitive
device, and althought several kilobucks about fifteen years ago, it was
not prohibitive. That unit was a of the type that appears in the drawing
'high
and that brings him to about 55 MHz. To generate that 55 MHz he has
several options: - Cascading two DDS chips to get many bits of
frequency resolution and leave the thing in open loop. I don't like
the absence of feedback in this option,
Why do you want feedback for a DDS?
It's not a PLL
Hi James,
the kind of experience that makes one a better engineer :)
bye,
Said
In a message dated 8/15/2009 14:35:41 Pacific Daylight Time,
james.p@jpl.nasa.gov writes:
Yes.. In our case, though, I think the microphonics were from movement of
the cavity lid, which wasn't very
Hi Rick,
wonder if the operators needed their hearing calibrated after long
exposures to that :)
A long time ago I designed and built a 1KHz ultra-low-distortion signal
generator using the original H/P design (Wien bridge(?) with a small lamp for
amplitude stability).
That lamp is a
a few have asked about the absorber I have
the sheets are roughly 23.5 x 23.5 inches and about 1/8 inch
thick
they weight approx 8.4 lbs each
they were packed between 40 and 45 sheets per wooden create and
there were 6 creates
The label from one of the sheets reads
PLESSEY MICROWAVE MATERIALS
Or at least that provides a reason to question the inherited design..
On 8/15/09 5:32 PM, saidj...@aol.com saidj...@aol.com wrote:
Hi James,
the kind of experience that makes one a better engineer :)
bye,
Said
In a message dated 8/15/2009 14:35:41 Pacific Daylight Time,
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