Hi Folks
I have finally got a machine ready to be my time server. I have OpenBSD
4.2 installed and am trying to fathom out how to configure it to use PPS.
I've been looking at this page:
http://www.david-taylor.myby.co.uk/ntp/FreeBSD-GPS-PPS.htm
...which actually deals with FreeBSD - don't
it's even easier than that. the PPS code is in and on by default, the
two things you need are to activate kernel timestamping with
nmeaattach (see /etc/rc.conf for an example) and then tell ntpd to use
the timedelta sensor (sensor * or sensor nmea0)
CK
On Mon, Mar 31, 2008 at 1:23 AM, Matthew
Quoth Chris Kuethe at 2008-03-31 19:06...
it's even easier than that. the PPS code is in and on by default, the
two things you need are to activate kernel timestamping with
nmeaattach (see /etc/rc.conf for an example) and then tell ntpd to use
the timedelta sensor (sensor * or sensor nmea0)
From: Richard (Rick) Karlquist [EMAIL PROTECTED]
Subject: Re: [time-nuts] Close-in phase noise measurements
Date: Sun, 30 Mar 2008 21:05:50 -0700
Message-ID: [EMAIL PROTECTED]
The relationship between phase noise and Allan variance is
a complex one and was described in papers at FCS in 1976
On Mon, Mar 31, 2008 at 1:54 AM, Matthew Smith [EMAIL PROTECTED] wrote:
Thanks! I know that you said it was easy, which is why I went the
OpenBSD route - didn't know it would be that easy though.
So, just to confirm, I need to change the rc.conf line to this, based on
the GPS being
The first problem that jumps immediately to my eye is
your power supply is backwards.
-Chuck Harris
Jenny Lee wrote:
Hi Everyone, I was hoping to get some words of wisdom on my oscillator that
only oscillates in simulation! I have a
MEMS device that resonates around 34 MHz at a given bias
Hello,
The transistor is NPN and are you applying possitive supply voltage to
the emitter and negative to the colector?
Regards,
Javier
Jenny Lee escribió:
Hi Everyone, I was hoping to get some words of wisdom on my oscillator that
only oscillates in simulation! I have a MEMS device that
Sorry for the previous noise... only zooming the image I saw that the
supply voltage is -10V :)
Regards,
Javier
--
Javier HerreroEMAIL: [EMAIL PROTECTED]
HV Sistemas S.L.
Jenny,
In your schematic I'm assuming the uppermost
transistor connection is the emitter.
Your bias scheme is unlikely to exhibit its paper
impedance at 34MHz. Any stray capacitance(s)
can easily result in AC paths to ground lower
than the L R impedances in your circuit.
The bias inductor
Message: 2
Date: Mon, 31 Mar 2008 21:20:43 +
From: Jenny Lee [EMAIL PROTECTED]
Subject: [time-nuts] Xtal-like Colpitts Oscillator
To: time-nuts@febo.com
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain; charset=iso-8859-1
Hi Everyone, I was hoping to get some words of wisdom
Jenny asked.
Hi Everyone, I was hoping to get some words of wisdom on my oscillator that
only oscillates in simulation! I have a MEMS device that resonates around
34 MHz at a given bias with Q of 100.
You have already received some very good advice. You might also try a
transistor with a
Pete wrote:
Jenny,
In your schematic I'm assuming the uppermost
transistor connection is the emitter.
Your bias scheme is unlikely to exhibit its paper
impedance at 34MHz. Any stray capacitance(s)
can easily result in AC paths to ground lower
than the L R impedances in your circuit.
Jenny Lee wrote:
Hi Everyone, I was hoping to get some words of wisdom on my oscillator that
only oscillates in simulation! I have a MEMS device that resonates around 34
MHz at a given bias with Q of 100. I fit the impedance into a six-element
equivalent model (similar to 4-element
Max Robinson wrote:
Jenny asked.
Hi Everyone, I was hoping to get some words of wisdom on my oscillator that
only oscillates in simulation! I have a MEMS device that resonates around
34 MHz at a given bias with Q of 100.
You have already received some very good advice. You might also
Having seen it discussed, I was wondering whether anyone has actually added
the Schottky diodes and prescaler chip to a 5334B to provide a C-channel
input. The matched Schottky quads (5082-2831) are no longer available, and
even the recommended replacements (5082-2303) seem scarce. Was thinking
Robert Berg wrote:
Having seen it discussed, I was wondering whether anyone has actually added
the Schottky diodes and prescaler chip to a 5334B to provide a C-channel
input. The matched Schottky quads (5082-2831) are no longer available, and
even the recommended replacements (5082-2303) seem
Bruce Griffiths wrote:
Robert Berg wrote:
Having seen it discussed, I was wondering whether anyone has actually added
the Schottky diodes and prescaler chip to a 5334B to provide a C-channel
input. The matched Schottky quads (5082-2831) are no longer available, and
even the recommended
I was thinking of buying a few dual shottkys (series configuration) in
SOT-23 package and I thought it would be a piece of cake finding those, but
interestingly, my usual part vendors (Digikey, Mouser, Newark, Allied) don't
carry any that I could use, at least if they do, I did not find them.
My usual choice for dual schottky in an SOT-23 is the BAT54. It comes in
four flavors:
BAT54 - single diode
BAT54A - Common Anode
BAT54C - Common Cathode
BAT54S - Series
It's rated at 30V/200mA.
Keith
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
I don't believe these are RF detectors, they look like switching diodes.
Even though they are Shottkys, the spec says they have a 5nS reverse
recovery time ???
That would be too slow for a 1 GHz counter.
I use a lot of BAV99, and while not being Shottkys, they have about the same
reverse
Didier Juges wrote:
I don't believe these are RF detectors, they look like switching diodes.
Even though they are Shottkys, the spec says they have a 5nS reverse
recovery time ???
That would be too slow for a 1 GHz counter.
I use a lot of BAV99, and while not being Shottkys, they have
Bruce Griffiths wrote:
Didier Juges wrote:
I don't believe these are RF detectors, they look like switching diodes.
Even though they are Shottkys, the spec says they have a 5nS reverse
recovery time ???
That would be too slow for a 1 GHz counter.
I use a lot of BAV99, and while not
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Bruce Griffiths
Sent: Monday, March 31, 2008 11:28 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Adding prescaler to HP 5334B
Didier Juges wrote:
I don't
Thanks so much for the feedbacks!
-Jenny Date: Tue, 1 Apr 2008 13:18:18 +1300 From: [EMAIL PROTECTED] To:
time-nuts@febo.com Subject: Re: [time-nuts] Xtal-like Colpitts Oscillator
Max Robinson wrote: Jenny asked. Hi Everyone, I was hoping to get some
words of wisdom on my oscillator
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