Ignacio wrote:
I'm not very sure that the DAC is working, I suppose that the unit
doesn't measure the DAC output, it reports the DAC commands. My
voltage figures is what LH reports (so the NTGS50AA reports,
probably what it is trying to do), but the frequency control pin of
the oscillator is
Paul,
Large plots are ok. They just get flagged by the server for approval.
/tvb (i5s)
> On Nov 11, 2014, at 8:03 PM, paul swed wrote:
>
> I was thinking about snapping a pix. Though it has to be pretty small to
> get through time-nuts.
> Clearly my units still aging/adjusting a positive EFC
I was thinking about snapping a pix. Though it has to be pretty small to
get through time-nuts.
Clearly my units still aging/adjusting a positive EFC rate.
Regards
Paul
WB8TSL
On Tue, Nov 11, 2014 at 9:12 PM, Bob Stewart wrote:
> Hi Paul,
> I saw the phase of the 10MHz signal dip by about 60ns t
Ignacio wrote:
I'm not very sure that the DAC is working, I suppose that the unit
doesn't measure the DAC output, it reports the DAC commands. My
voltage figures is what LH reports (so the NTGS50AA reports,
probably what it is trying to do), but the frequency control pin of
the oscillator is
Hi,
I found in the top side a quad op amp, a LT 1014, surrounded by your
forest of resistors. The output of one of these op amps goes directly
to the control voltage input. I'm in the right track.
It is very late here, 03:15 AM so I must go to the bed. Working so late
is a call for disasters
Hi Paul,
I saw the phase of the 10MHz signal dip by about 60ns twice today as compared
to my homebrew GPSDO. Given what I know about the design of my unit, it's hard
to believe it could follow the path the phase difference took, but I suppose
anything's possible. Bob posted a graph showing the
Hi,
Removing the oscillator for testing and replacing it with other if it
was the culprit was my first option. I have a spare Trimble oscillator
that probably came from other NTGS50AA since it still have the foam band
attached, but this oscillator is really aged, it needs 7.91 V to bring
it
Bob
I will say that I am watching the noise of the pps ti in the z3811 program.
Granted its been running 30 some hours now. Virtually nothing in time. My
fingers are crossed it will clean up.
I do like the unit quite well. Have to thank Bert for even cluing me in.
So I do agree quite a nice unit.
R
Hi
A .. I misunderstood what you were saying. As I now understand, the inputs
to the DAC move around in the software, but the actual voltage out of the DAC
is always stuck at 5V.
The DAC (if it’s like a TBolt) is the sum of a set of signals into an op amp.
There is a forest of metal film r
Hi,
I meant 2 years, it is quite late here.
I'm not very sure that the DAC is working, I suppose that the unit
doesn't measure the DAC output, it reports the DAC commands. My voltage
figures is what LH reports (so the NTGS50AA reports, probably what it is
trying to do), but the frequency contr
I have seen this caused by the oscillator not responding to the EFC signal.
Fixed it by swapping in a MV-89 oscillator.
The oscillators used in these units don't output an oven temperature monitor
signal.
___
ti
Hi
The only gotcha is accuracy.
If that is part of the equation, then even a pretty dumpy OCXO properly GPSDO’d
will beat one that is a very good OCXO indeed.
A darn good OCXO will age down in the 1x10^-11 per day range. In a bit over 10
days you may be past +/- 1x10^-10.
An OCXO based GPSDO
Mark wrote:
I find the concept of occasionally adjusting a good OCXO which in
turn is used as a reference works well for me.I have some that
haven't needed adjustment for over 2 years (they are still well
within one part per billion of being on frequency.)
A few of us have advocated thi
Hi
Ok, the gizmo you have is pretty similar to a Thunderbolt in terms of what they
did for circuits. It’s by no means identical and I have not traced either one
out far enough to have a schematic.
At least from the TBolt - your DAC is working. The voltage is moving around and
it’s getting low
Hello,
After 2 yeses of continuous operation my NTGS50AA turned its red led on
and stopped working. A check with LH shows "OSC: BAD" and "OSC age
alarm" assuming that the oscillator had aged too much.
I didn't believe this because when working, the DAC control voltage was
around 2.9 V, in fact
Hi
Here’s another way to look at the second unit - What would you pay (on an
auction site) for the parts? Since there’s a warranty on the box, all would be
100% good working parts with a solid guarantee and paid shipping back:
Lucent low EMI DC-DC converter “power brick” - $35 + $5 ship
MTI 260
I am in Australia and the accuracy of the NITZ service can be slow by up to
15 SECONDS. I have no idea why it is so bad. You can try this for yourself.
Just get a GSM modem connected to your laptop, set it up to accept NITZ
updates and print the results on the serial port, and take a drive around
y
John Miles did the phase noise measurments, they are avaible here:
http://nt7s.com/2014/11/si5351a-investigations-part-7/
BR
Thomas.
2014-11-11 21:49 GMT+01:00 Joseph Gray :
> Some of you have probably already heard of this new clock generator chip
> from Si. News of a board with this chip fro
Hi
When you look at the parts some people use in radios, this one is better than
some of them. No, it’s not what I would use.
Bob
> On Nov 11, 2014, at 3:49 PM, Joseph Gray wrote:
>
> Some of you have probably already heard of this new clock generator chip
> from Si. News of a board with this
Hi
This is one of several that come up when I do a search at Mouser:
http://www.mouser.com/ProductDetail/ABRACON/ASVTX11-14400MHZ-T/?qs=sGAEpiMZZMsBj6bBr9Q9aTQ72VsxIq1y8x3GpFIJ334%3d
That’s the link, to the full reel. At one piece they are $5.89 each.
Temperature spec is +/- 2.5 ppm over -30 t
On 11/11/2014 21:52, Tom Harris wrote:
How are you getting time from the GSM network? If you are using the NITZ
(look it up) service then you can use an unactivated SIM for free, but the
accuracy is woeful, it can be seconds out.
I'm not at the moment; mobile phones do set their clocks from the
The specs for period, cycle-to-cycle and phase jitter are on page 6 of the
data sheet, which is here:
http://www.adafruit.com/datasheets/Si5351.pdf
Wayne
On Tue, Nov 11, 2014 at 12:49 PM, Joseph Gray wrote:
> Some of you have probably already heard of this new clock generator chip
> from Si.
How are you getting time from the GSM network? If you are using the NITZ
(look it up) service then you can use an unactivated SIM for free, but the
accuracy is woeful, it can be seconds out.
Else you will have to have a live SIM and use NTP to a server. If you make
any progress please post to the
Connor-Winfield has a line of TCXO's with 0.1 ppm stability that can be
bought from Digi-Key in single unit quantities for about $25. Search for
M100F.
They don't have a 14.4 Mhz, but they do have 10.0 Mhz, which you
indicated could also work for you.
Regards,
John
AC0ZG
On 11/11/2014 11:
Hi I have not had much luck with ocxo's sourced from the usual auction site.
By far and away the best value for money for me has been found in some packaged
frequency standards containing OCXO's and a non auction site purchase of a
"BVA" OCXO.
I find the concept of occasionally adjusting a
How accurately can you set, and keep in sync a local clock (in the UK)
by getting timing from a cellular network using a very low cost GSM/GPRS
modem module such as a SIM900? Is it possible to get better than
hundreds of microseconds for example, perhaps even a few tens of us? How
frequently ca
Some of you have probably already heard of this new clock generator chip
from Si. News of a board with this chip from Adafruit just came up on a
local Amateur list today. A quick Google shows that some folks have used
this chip in homebrew SSB rigs.
My concern would be that when this chip generate
The Ta caps in old HP gear should last virtually forever, especially
if they have already lasted for decades. What you are referring to as
"wet slug" Ta caps are mostly dry solid ones in hermetically sealed
cans. There can be some actual wet slug types, but only in certain
spots where their uni
> If 0.2 ppm over a narrow range is the objective, that sounds like a TCXO
application.
Please point me to such a TCXO at 14.4 MHz that is affordable.
Joe Gray
W5JG
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Hi
Ok, let’s back off a bit.
If 0.2 ppm over a narrow range is the objective, that sounds like a TCXO
application. If you really are only after the 14.4 MHz, that’s the quick / easy
way to go. Everything running on 3.3V, total current may be below 10 ma. Far
fewer parts involved. A lot depends
Joe
It is not clear to me what your goal is. Simplicity, cost or performance. A
PLL based on 1 pps is not optimum.
I call this approach GPSPLL versus GPSDO. Thanks to work done by Karen in
Moscow I found out that you can program a $14 ublox M7 to frequencies above
1 KHz. If you use 200 KHz fo
> it would not be OK to design a daemon which handles the crypto stuff or the
> control packets in a root-process, those should go in a sandbox.
Absolutely agree, in my previous life in the data security arena (crypto, data
security, white hat tester etc..), doing that sort of thing in a privile
In message <54615794.3040...@rubidium.dyndns.org>, Magnus Danielson writes:
>I'm just saying that the NTP processing and the NTP monitoring may not
>need to run by the same daemon necessarily.
As the Varnish architecture shows, I'm fully in agreement with this.
I should also add that o
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