My approach in progress is LVPECL driver from the master clock to a low
cost clock cleaner PLL with a low phase noise VCXO (mine are crysteks and
abracon depending on what I felt like at the moment).
Does that sort of approach match your requirement? It isn't as low cost as
a dist amp but the
Interesting.
I have also been thinking that it might not be too difficult to
implement using Beaglebone Black, Raspberry PI, or even one or another
flavour of Arduino. Lots of possibilities from simple to not so simple.
cheers, Graham ve3gtc
On 2014-11-23 21:38, Neil Schroeder wrote:
If
Hello,
Since the questions has been asked I will reply also apologies for the “advert”
We make ultra low noise distribution amplifiers.
1 Hz noise is –135 dBc and we can achieve –172 dBc noise floor if we
carefully set all the gains.
www.ptsyst.com/DA1-100-10-B.pdf
But these are expensive
The current implementation used in WR was developed by Tomasz
Wlostowski in the frame of his MSc thesis, following the ideas of
Pablo Alvarez which Bruce pointed to earlier. As you can see in
Tomasz's dissertation [1], there was not a lot of investigation on
optimal strategies for DDTMD
Hi
Here’s the problem:
Spectrum analyzers, synthesizers, signal generatros, and the like all tend to
follow a common design approach. They take the 10 MHz reference in and run it
through a narrowband PLL. Not every one of them, but 99% of them. The same is
true of microwave multipliers and
On 24 November 2014 at 03:44, Said Jackson via time-nuts
time-nuts@febo.com wrote:
On the 20MHz units there is already a strong buffer that can drive 50 Ohms
terminations so adding a buffer in front of the coax connector on that
version would have just added unnecessary phase and AM noise,
On 11/24/14, 2:20 AM, Graham wrote:
Interesting.
I have also been thinking that it might not be too difficult to
implement using Beaglebone Black, Raspberry PI, or even one or another
flavour of Arduino. Lots of possibilities from simple to not so simple.
The challenge is always trying to
Both units are sold.
Craig McCartney
Palomar Park, CA
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
For those who are interested, a relevant dissertation can be found here:
http://dspace.mit.edu/bitstream/handle/1721.1/71453/795174737.pdf
Unfortunately, you can't print it, but you can read it. A rather complete
discussion of the construction of the experimental apparatus is included.
On
That is a good paper. I can't understand much of it.
There you go thats the measure. :-)
Thanks
Paul
WB8TSL
On Mon, Nov 24, 2014 at 9:05 AM, Mark Kahrs mark.ka...@gmail.com wrote:
For those who are interested, a relevant dissertation can be found here:
On 11/24/14, 6:05 AM, Mark Kahrs wrote:
For those who are interested, a relevant dissertation can be found here:
http://dspace.mit.edu/bitstream/handle/1721.1/71453/795174737.pdf
Unfortunately, you can't print it, but you can read it. A rather complete
discussion of the construction of the
Started plotting some sampled data from my experimental system, and
interestingly, it seems to have a 1/f^2 slope, rather than a 1/f slope.
I had expected the amplifier noise to dominate, but perhaps one of the
myriad other noise sources is contributing as well (e.g. sample clock
jitter, ADC
Hi,
This is a good and reasonable description of what we normally need. I agree.
Some amateur like me want some more than the normal, and If you want, more than
the necessary. This happen only for testing ours ability to improve the
performance of our instruments we use as hobbist.
For this
I use an older XP based drag and drop freeware PDF unlocker that strips many
PDF restrictions. It made the file below quite printable.
Bob L.
Sent: Monday, November 24, 2014 at 9:05 AM
From: Mark Kahrs mark.ka...@gmail.com
To: Discussion of precise time and frequency measurement
I you are really really dead set on building your own there are lots of
chips available with varying levels of external parts needed.
An economical and versatile solution is to use one of the digi TS-One or
portserver TS terminal servers. They are a little pricey new, but, last time
I needed
Thanks Pablo.
I've been finding that my implementation is a very good noise detector
(in all kinds of fun ways) and my most recent effort has been at the
hardware level in better layout, shielding and in reducing the number of
noise sources.
The impact of non-random noise is that
Correct, and thats why its all a bad trade off if you have to use 50 Ohms
termination. Either more heat or more PN, and more circuitry.
So driving 50 Ohms inputs is not optimal here, 1M inputs are much better for
this purpose.
I had discussed the advantages of CMOS open-ended termination some
We should not forget that the LTE is not a free standing frequency source:
it is steered to GPS signals and, in the long term, will reflect the
accuracy of GPS and the stability of the as-received signal.
From the ADEV plot in the user manual, it looks like the time constant for
steering of the
The Linux program Okular has no trouble printing this file.
-Chuck Harris
Robert LaJeunesse wrote:
I use an older XP based drag and drop freeware PDF unlocker that strips many
PDF
restrictions. It made the file below quite printable.
Bob L.
Sent: Monday, November 24, 2014 at 9:05 AM From:
Hi Martyn,
I looked at the specifications. Very nice indeed!!
I will contact you off list for more info...Bill
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Martyn Smith
Sent: Monday, November 24, 2014 2:31 AM
To: time-nuts@febo.com
Subject:
sorry, Bob, I spaced this one. The dac is indeed a trimpot, and if the
external source is enabled, the 1:1 pll controls the ocxo through, as you
thought, a fast loop, about 2 sec t/c and the trimpot dac is not connected. The
pll is an ecl phase detector and a pump, very simple. So the “zero
Hi Rick,
Thanks for your response and comments.
Although the term additive and residual phase noise have been used
interchangeably in the literature to this day, I agree with you that they
shouldn't, but with my following interpretation.
To me residual phase noise applies to the measurement
Hi Luciano,
Thanks for sharing that data. Do you have a link to the NIST distribution
amplifier?
When you're ready I hope you'll share more data on your MDT123 design.
Regards...Bill
-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of
tim...@timeok.it
So to verify the initial results we saw we tested another 10MHz DIP-14 unit
on a different ADEV test-set, and the results are similar.
See the attached ADEV plot of a random unit.
This was actually the synthesized output from the board set to 20MHz from
the 10MHz TCXO, then fed through a
Although my current project doesn't have the strict requirements that
many of you have, I thought I would mention part of it, due to the
recent talk of distribution amps.
I am putting one of the FE5680A's that I bought a while back into a
permanent home. I have a nice box from a gutted HP
Hi
On Nov 24, 2014, at 1:47 PM, Don Latham d...@montana.com wrote:
sorry, Bob, I spaced this one. The dac is indeed a trimpot, and if the
external source is enabled, the 1:1 pll controls the ocxo through, as you
thought, a fast loop, about 2 sec t/c and the trimpot dac is not
I have done a bit of searching and found that what I want to do is
nothing really new and their are several off the shelf applications
which will work just fine - linux and Windows based hence the mention of
the Raspberry PI and Beaglebone Black. Some of the higher end Arduinos
(i.e. Yu) are
Said:
Several times you've mentioned a low noise LDO regulator. I've not seen
a device specified -- can you share?
Also, yesterday, in response to my question about using an existing
antenna, you basically said, Try it. Well, I did -- working great for
over 24 hours. At this moment, I
Hi
The Linear LT1764 is a pretty good part. It’s nice and rugged / tough to kill.
Bypass the output with a few hundred uF of tantalum caps. Keep at least a volt
between input and output.
Bob
On Nov 24, 2014, at 7:12 PM, Jim Sanford wb4...@wb4gcs.org wrote:
Said:
Several times you've
Hey, that's what the 'tute website said, I'm just reporting.
The aforementioned dissertation features the same octagonal cell as
described in the paper.
For those of you with access to knowledge of ultracold quartz chambers, go
right on ahead.
On Mon, Nov 24, 2014 at 12:13 PM, Chuck Harris
Jim,
Bobs suggestion is good; look at for example the LT3060 for something that
needs less than 100mA.
Glad your antenna is working well. What C/No numbers is uBlox indicating?
Bye,
Said
Sent from my iPad
On Nov 24, 2014, at 16:28, Bob Camp kb...@n1k.org wrote:
Hi
The Linear LT1764 is
Said:
I'm seeing C/No numbers between 50.0 and 41.0 for the green birds.
I'm seeing 27.0 to 42 on the blue birds. Not quite sure what the
difference between green and blue is. UBlox is acting kind of funny --
it ignores any attempt to click on an icon or any of the menu bar
items. Yet it
It won't respond the LTE LITE is send only.
I found another program from the Chip manufacturer and it behaves teh same
as expected and mentioned by Said.
So putty works as well as anything.
OK my first external fun with the LTE.
Since I had no 74AS74 I used a 74HC74 chip running at 4.5V. This
There is a protocol for ending serial commands over telnet (tcp): RFC2217
See http://tools.ietf.org/html/rfc2217
A number of command line tools, like ser2net and netcat use the protocol.
Some of the small serial servers support it and it can make using serial
remotely tunneled over tcp seamless.
Jim,
41 to 50dB is great.
The height difference may be MSL to GPS height?
Bye,
Said
Sent From iPhone
On Nov 24, 2014, at 18:39, Jim Sanford wb4...@wb4gcs.org wrote:
Said:
I'm seeing C/No numbers between 50.0 and 41.0 for the green birds. I'm
seeing 27.0 to 42 on the blue birds. Not
Said Jackson said:
Correct, and thats why its all a bad trade off if you have to use 50 Ohms
termination. Either more heat or more PN, and more circuitry.
So driving 50 Ohms inputs is not optimal here, 1M inputs are much better for
this purpose.
That only works if you have a (very) short
kb...@n1k.org said:
Maybe Tom needs a Microsoft Windows Update on his GPSDO firmware :) For some
reason the very thought of Microsoft getting involved in something like that
makes me shudderâ¦
For good reason. A friend's scope picked up a virus.
--
These are my opinions. I hate spam.
I once bought an HP16700 series logic analyzer off of Ebay that had a directory
filled with porn on it... but that is a Unix machine.
for good reason. A friend's scope picked up a virus.
___
38 matches
Mail list logo
