For the real analog fans, how about a 1 Hz sinewave output and watch for
the zero-crossings! G Precise? No!
David
--
SatSignal software - quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
On 02/07/2012 02:16 AM, Bob Camp wrote:
Hi
When the customers started asking in the 1930's, generating a square wave at
high frequency was not so easy….
Which is my point, the power of tradition can sometimes be stronger than
logical reasoning for the application needs. Today many of the
Yes, I was thinking of trying a PICTIC II partial redesign with a Xilinx
CPLD, using other type of fast turn off diodes and so on.
On Tue, Feb 7, 2012 at 8:28 AM, Attila Kinali att...@kinali.ch wrote:
On Sun, 5 Feb 2012 19:55:36 -0900 (AKST)
Richard H McCorkle mccor...@ptialaska.net wrote:
On 02/07/2012 05:58 AM, Hal Murray wrote:
mag...@rubidium.dyndns.org said:
Oh... nothing really beats it's what customers traditionally asks for
Squarewave out provides high slew-rate which reduces the effect of
additional noise.
Right. But if you have a single frequency you can easily
On 02/07/2012 09:02 AM, David J Taylor wrote:
For the real analog fans, how about a 1 Hz sinewave output and watch for
the zero-crossings! G Precise? No!
11 uHz sine anyone, 24 hours period?
Cheers,
Magnus
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On 02/07/2012 03:12 AM, Hal Murray wrote:
mag...@rubidium.dyndns.org said:
Not quite right. If you lock up the clock, you do not lock to the birds,
but to GPS time or UTC as received over GPS. The observed time of the birds
would be a bad solution since you can't see a particular bird
Or 23h 56m 4.091s
/tvb
11 uHz sine anyone, 24 hours period?
Cheers,
Magnus
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att...@kinali.ch said:
BTW: does anyone know how these days low cost FPGAs perform in terms of
jitter? (the data sheets are kind of scarce in that regard). And how do they
compare to state of the art ECL logic?
Generally, not good.
The general problem is that they have a lot of logic and a
To enhance the PICTIC II performance can step recovery diodes be used?
Maybe the fast turn off can boost the switching capabilities of the
interpolator for best resolution...
On Tue, Feb 7, 2012 at 12:35 PM, Hal Murray hmur...@megapathdsl.net wrote:
att...@kinali.ch said:
BTW: does anyone
On Tue, 7 Feb 2012 08:28:14 +0100, Attila Kinali att...@kinali.ch
wrote:
On Sun, 5 Feb 2012 19:55:36 -0900 (AKST)
Richard H McCorkle mccor...@ptialaska.net wrote:
While using a faster timebase or higher interpolator gain increases
the resolution that doesn?t imply the accuracy will also
Step recovery diodes turn off fast but have a relatively long storage
time. The fastest switched current integrators use schottky diodes.
On Tue, 7 Feb 2012 14:06:55 +0100, Azelio Boriani
azelio.bori...@screen.it wrote:
To enhance the PICTIC II performance can step recovery diodes be used?
Hi
Thank goodness for that inertia. I can still cable up a 100Kcps sine wave
standard to run stuff from long ago. When I run into a box that uses a T1
signal for a clock reference - not so easy in the basement.
Bob
-Original Message-
From: time-nuts-boun...@febo.com
Hello,
As has been mentioned here before, the output of the non-tunable
FE-5680A's has been noted to have low-level spurs in it - no doubt due
to the way the various frequency loops are derived within, some using
DDS techniques. It is for this reason that when I packaged my FE-5680A
in its
Hi
The phase noise of the FE's is not great, even inside +/- 3 KHz. To do an
adequate job of cleaning them up, something like a 1 Hz loop bandwidth PLL
would be needed.
Bob
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of C. Turner
Use a MV89 or something like it and lock it to the 5680A with a 10 to 100
Hz analog filter. You will like the results at 10 GHz.
Bert Kehrenn
In a message dated 2/7/2012 12:48:57 P.M. Eastern Standard Time,
tur...@ussc.com writes:
Hello,
As has been mentioned here before, the output of
I am just finishing my promised stability and phase noise measurements
on a batch of inexpensive Rb standards; I hope to publish the results
tomorrow evening.
In the meantime, I've looked at two of the FE-5680s and their phase
noise is significantly worse than either the Efratom FRS or the
li...@rtty.us said:
Thank goodness for that inertia. I can still cable up a 100Kcps sine wave
standard to run stuff from long ago. When I run into a box that uses a T1
signal for a clock reference - not so easy in the basement.
How much gear is there that uses T1 for a clock input?
Is there
On 02/07/2012 08:12 PM, Hal Murray wrote:
li...@rtty.us said:
Thank goodness for that inertia. I can still cable up a 100Kcps sine wave
standard to run stuff from long ago. When I run into a box that uses a T1
signal for a clock reference - not so easy in the basement.
How much gear is there
Related question: Assuming I'm using 10MHz sine wave. What's the
best physical cable to use? Is there any good reason to use 50 ohm
cable? What about 75 ohm? I looked at a schematic of my counter
and it looks like the 10MHz signal hits some high impedance chip
inside.RG6 seems like
On Tue, 7 Feb 2012 12:19:11 -0800
Chris Albertson albertson.ch...@gmail.com wrote:
Related question: Assuming I'm using 10MHz sine wave. What's the
best physical cable to use? Is there any good reason to use 50 ohm
cable? What about 75 ohm? I looked at a schematic of my counter
and
On Tue, 7 Feb 2012 21:59:18 +0100
Attila Kinali att...@kinali.ch wrote:
Related question: Assuming I'm using 10MHz sine wave. What's the
best physical cable to use? Is there any good reason to use 50 ohm
cable? What about 75 ohm? I looked at a schematic of my counter
and it looks
On Tue, 07 Feb 2012 16:15:44 -0500
Mike Naruta AA8K a...@comcast.net wrote:
On 02/07/2012 03:59 PM, Attila Kinali wrote:
while TV and radio uses 75R. (there was once a reason
for this, but i don't know it).
A 4:1 balun takes old 300 ohm twinlead to 75 ohms.
Thanks! This explains half it
Try this for a history about the 50 OHM impedance:
http://www.rfcafe.com/references/electrical/history-of-50-ohms.htm
On Tue, Feb 7, 2012 at 10:30 PM, Attila Kinali att...@kinali.ch wrote:
On Tue, 07 Feb 2012 16:15:44 -0500
Mike Naruta AA8K a...@comcast.net wrote:
On 02/07/2012 03:59 PM,
On Tue, Feb 7, 2012 at 1:30 PM, Attila Kinali att...@kinali.ch wrote:
On Tue, 07 Feb 2012 16:15:44 -0500
Mike Naruta AA8K a...@comcast.net wrote:
On 02/07/2012 03:59 PM, Attila Kinali wrote:
while TV and radio uses 75R. (there was once a reason
for this, but i don't know it).
A 4:1 balun
50 ohms is a compromise between maximum power transfer and minimum
attenuation, as mentioned in page 9 of Network Analyzer Basics
(http://cp.literature.agilent.com/litweb/pdf/5965-7917E.pdf)
Regards,
Roberto EB4EQA
-Original Message-
From: time-nuts-boun...@febo.com
On 2/7/2012 4:30 PM, Attila Kinali wrote:
On Tue, 07 Feb 2012 16:15:44 -0500
Mike Naruta AA8Ka...@comcast.net wrote:
On 02/07/2012 03:59 PM, Attila Kinali wrote:
while TV and radio uses 75R. (there was once a reason
for this, but i don't know it).
A 4:1 balun takes old 300 ohm twinlead to
Hi
As long as you are running a sine wave, and you don't change cables, you can
run just about anything. The phase errors / reflections will work themselves
out.
50 ohm plastic dielectric cable turns out to be the best for power handling
at reasonable loss. 75 ohm cable turns out to be the best
On Tue, Feb 7, 2012 at 1:03 PM, Attila Kinali att...@kinali.ch wrote:
Addendum: Your counter input is mostlikely 50R. Even if it just enters
a chip, as the chip itself should be matched to 50R. The input impedance
should be noted in the manual of the counter.
The counter specs say that any
On 2/7/12 1:30 PM, Attila Kinali wrote:
On Tue, 07 Feb 2012 16:15:44 -0500
Mike Naruta AA8Ka...@comcast.net wrote:
On 02/07/2012 03:59 PM, Attila Kinali wrote:
while TV and radio uses 75R. (there was once a reason
for this, but i don't know it).
A 4:1 balun takes old 300 ohm twinlead to 75
There is no particular advantage in one or the other, at least not
for most applications. It's tradition that measurement and (most) RF
gear uses 50R, while TV and radio uses 75R. (there was once a reason
for this, but i don't know it).
FYI,
The reason there are two primary impedance's in
Hi
Modern gear often has high input standard plugs. People tend to daisy chain
gear with T connectors. That makes for issues if they are all low impedance.
Bob
On Feb 7, 2012, at 5:31 PM, Chris Albertson albertson.ch...@gmail.com wrote:
On Tue, Feb 7, 2012 at 1:03 PM, Attila Kinali
Just a FYI, the standard connectors for 75 and 50 ohms are a little
different. I will leave it at that, but there is plenty of info on the net
regarding the differences.
--Original Message--
From: Tom Miller
Sender: time-nuts-boun...@febo.com
To: time-nuts@febo.com
ReplyTo: Tom Miller
Azelio Boriani wrote:
Try this for a history about the 50 OHM impedance:
http://www.rfcafe.com/references/electrical/history-of-50-ohms.htm
The reference is full of errors. The lowest loss in coax
occurs when the ratio of the diameters is 3.6 to 1, regardless
of dielectric. For air
A 10Mhz to T1 clock generator would be a cool project but in the event I were
to need a standalone T1 clock source at home I'd probably just grab a CSU / DSU
from ebay (or ask one of my former employers if they would let me acquire one
from their junk pile) that could serve as clock generator.
GPS requires a good view of the sky, Hard to do in say the 7th floor
of a 40 story building if you have no windows. I'm wondering about
using the new digital TV signals for timing.
I'm pretty sure there is time code in the signal and I'm pretty sure
the bits are clocked at a very accurate
I think the real relation is 50 ohm coax is just
75 ohm air line with polyethylene dielectric added.
-Chuck Harris
Rick Karlquist wrote:
Azelio Boriani wrote:
Try this for a history about the 50 OHM impedance:
http://www.rfcafe.com/references/electrical/history-of-50-ohms.htm
The reference
You might be able to find the PCR clock at 90kHz, but.. PCR clocks are usually
just decent oscillators, nothing special.
GPS requires a good view of the sky, Hard to do in say the 7th floor
of a 40 story building if you have no windows. I'm wondering about
using the new digital TV
The DTV signal coding has a major problem in that it is not
deterministic - they can't even synchronize the audio and
video. There have been many workshops on this at the Audio
Engineering Society conventions. I doubt there is any useable timing in it.
David McGaw
At 09:01 PM 2/7/2012,
On 2/7/12 6:01 PM, Chris Albertson wrote:
GPS requires a good view of the sky, Hard to do in say the 7th floor
of a 40 story building if you have no windows. I'm wondering about
using the new digital TV signals for timing.
I'm pretty sure there is time code in the signal and I'm pretty sure
albertson.ch...@gmail.com said:
The plan is to try and phase lock a local oscillator and use a very long
time constant on the loop filter. I bet the TV transmitters are locked to
GPS and over a long enough time are as good as GPS. Also in many cities
there are many TV transmitters, should
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