In the .01 to 10 second range the OCXO provides a lower noise floor than
the TBolt. The TBolt provides better accuracy.
...although the TBolt itself has an OCXO built-in...
The catch is that the software keeps adjusting that OCXO, making it track the
GPS signal.
That gives you great long
Building your own backyard continental drift hardware would be high on the
coolness scale.
That should be within reason for a semi-nut. All it takes is a good GPS
setup. The ballpark motion of the San Andreas fault is an inch per year.
Around here (Silicon Valley), it's reasonably common
How about Planetized Back Yard (*) Medium LBI? If you, the measurement
enthusiast, have decent gps hardware + see yourself as 1 point in the LBI +
have
good timestamps for your measurement + a decent protocol to combine them I
would
say Radio astronomy for fun profit!. Mostly fun in this
Sent from my Banana jr (tm) Mobile Device
On Mar 18, 2011, at 9:20 PM, li...@lazygranch.com wrote:
http://www.astronomycast.com
Episode 211 was a good primer on celestial navigation. It covers time piece
construction.
Building your own backyard continental drift hardware would be
Hi
Alan variance / short term stability / medium term stability is what will
impact your measurements noise. That's not to surprising - noise on the
standard gives you noise on the measurement.
If for some reason an internal standard is more quiet than an external
standard, the internal may
Can anybody confirm the supply voltages for the Efratom 105243 10MHz OCXO,
please?
Like this:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItemitem=280558808335
This site indicates +24v for both the oven the oscillator, but I am
suspicious of its accuracy.
The pinout given in incorrect, I've
It all depend on you latitude. For all we know you might live 0.01
millimeter from the North Pole and your numbers are correct for you
location.
But the Equator is about 40075160 meters around Divide that by
(24*60*60) to get meters per second
But what you my be forgetting is that you don't
On Fri, Mar 18, 2011 at 8:31 PM, jimlux jim...@earthlink.net wrote:
That's an interesting idea, but I think all the orbit data for GPS
satellites
is Earth relative rather than star relative. I wonder if the group that
drives the GPS satellites even knows their location relative to the stars.
Dick,
Can you send me the manual, or upload it directly to my manuals page?
Thanks es 73,
Didier KO4BB
Sent from my BlackBerry Wireless thingy while I do other things...
-Original Message-
From: Richard W. Solomon w1...@earthlink.net
Sender: time-nuts-boun...@febo.com
Date: Thu, 17
Cezary Rozluski wrote:
Well – it is nice solution presented, but I would like ask you what
would be from time-nuts perspective simple (the simplest ?) solution
to drive such 50/60 Hz clocks without to much overweighed stuff (and
of course without modifying the clock itself addig e.g step motor
Robert LaJeunesse wrote:
Poor man's solution: Use an Arduino to read the Thunderbolt 1PPS and lock a 50Hz
(or 60Hz) square wave to the 1PPS. Any resulting jitter can likely be kept in
the tens of microsecond range, easily filtered out by the clock mechanics.
Filter the square wave a bit and
Hi
Most likely the lowest parts count is to divide to a narrow(ish) 20 Hz square
wave and then drive a resonated transformer with a pulse. The output won't look
pretty, but it should drive a small clock motor just fine. Done properly, there
should be very little power involved.
If you are
Since the 53320A TCXO option has a 1s ADEV spec of 1E-9 whereas the OCXO
option has a 1s ADEV spec of 1E-11 and the PLL bandwidth is unlikely (no
info on the PLL bandwidth available from datasheet) to be very large the
OCXO contribution to measurement uncertainty will likely be
significantly
An OTT solution might employ a regenerative divider to generate a 15MHz
signal from a 10MHz input followed by a digital divide by 250,000 circuit.
One could employ an inexpensive Gilbert cell mixer in the regenerative
divider to keep the cost down.
Bruce
Bob Camp wrote:
Hi
Most likely the
Hi
Lucent simply divided the 10 MHz by two and then tripled that in their standard
base station gear. Lots of ways to do it. None of them very hard at all.
Bob
On Mar 19, 2011, at 4:30 PM, Bruce Griffiths wrote:
An OTT solution might employ a regenerative divider to generate a 15MHz
Can anybody confirm the supply voltages for the Efratom 105243...
The pinout shown is close. The oscillator supply voltage on the
one I have in circuit is +15 @ low current. The Oven requires
24VDC @ .25A and this drops to under 100ma when the unit
reaches operating temperature. There apparently
Hi
The board looks a lot like a pull from a Lucent base station. The voltages
would all make sense in that context. The unit swaps in for an LPRO and the 15V
would be easy enough to come up with. I'd bet they ran both pins off of +24
though.
Bob
On Mar 19, 2011, at 5:20 PM, Arthur Dent
Wrote: It seems like everybody is telling me go for the cheaper, add the OCXO
later on if you need it - but that's not what I'm after. What I'd really like
to do is to make up my mind based on educated opinions on this list whether the
built-in OXCO option offers any advantage at all compared
Hi
The 3801 is a pretty good box. In some cases I have seen them take months to
achieve full stability. The leave powered on at all times rule definitely
applies to them.
Bob
On Mar 19, 2011, at 6:22 PM, Perry Sandeen wrote:
Wrote: It seems like everybody is telling me go for the cheaper,
jimlux wrote:
A 10-12m diameter dish is probably close to the minimum feasible
aperture.
A 4m dish can be made to work in conjunction with a mauch larger dish
(eg 30m).
The original speculation was for measuring the small change in earth
rotation rate, for which some sort of
Bruce Griffiths wrote:
jimlux wrote:
A 10-12m diameter dish is probably close to the minimum feasible
aperture.
A 4m dish can be made to work in conjunction with a mauch larger dish
(eg 30m).
The original speculation was for measuring the small change in earth
rotation rate, for which
21 matches
Mail list logo
