Hi
CMOS is what you want rather than TTL in this day and age. Propagation delay
and jitter are
both much better than any of the TTL families.
NC7SZ125:
Prop delay 2.6 ns
Output high 50 ma max 32 ma rated
Output low 50 ma max 32 ma rated
(rated = ~0.5V off rail at 4.5V supply)
74S140
Prop
Hi
There are a variety of GPS devices that put out a PPS. uBlox makes some, there
are a number of other companies that do so. The PPS comes out modulo the local
timebase. On a precision part, there is a “sawtooth correction” message that
also
comes out to further quantify the best guess time of
Tom,
Thanks for the explanation of clock ensembles. That answered a few
questions I've had for a while.
Regarding your comments on collecting raw time data from GPS and post
processing it. Can you provide any reference info, links, etc. with more
detail on that topic?
Clearly I'd need a GPS
I believe the FTS-4040 was originallly a Time and Frequency Solutions product
and the manual for their FTS-4060 can be found here.
www.to-way.com/tf/4060man.pdf
That shows the pre-regulator DC power requirements as a nominal 26 V, with a
range of 22 to 30 V.
I'm not sure how relevant this
30V seems to be the answer. I am going to attempt to repair the factory
switcher. I found one electrolytic gone and few other things suspect. So I
will know for sure. Model number (custom) suggests 30V as well. As to
manuals, I can go as old as 4040B, but not A. I do have an option of
Hi
….. and here I was wondering if it had ever gone out :) Glad it made it.
No, I did not run any single frequency units beside it. It is much better than
any similar plot
I’ve done in the past on an L1 only part.
Indeed, as long as you just look at the first ~ 100 seconds, the “reference
Hi
You can access an “NTRIP stream” from various free sites. There is some
mumbo jumbo on some of them to get an account. There are streams dedicated
to “clock and orbit correction”. CLK11 and CLK93 are two fairly common ones.
Since NTRIP is a real time product (as in < 30 seconds delay) it can
If you search for "GNSS time transfer" you will find a lot of papers etc.
For example these might get you started:
https://www.bipm.org/ws/CCTF/TAI_TRAINING/Allowed/Fundamentals/Training-2012-GNSS-Defraigne.pdf
https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7909843
I tried to collect some
On Mon, Mar 18, 2019 at 8:03 AM Rodger via time-nuts
wrote:
>
> Tom,
>
> Thanks for the explanation of clock ensembles. That answered a few
> questions I've had for a while.
> Regarding your comments on collecting raw time data from GPS and post
> processing it. Can you provide any reference
This project www.openttp.org provides software for post-processing of raw
data for time-transfer from some currently available single frequency
receivers. It provides CGGTTS and RINEX, the latter for use with the
various PPP services. There are some tools in there too for doing eg common
view and
Bob,
I recalled the plot you posted a few days ago. Nice plot on the F9P,
BTW. Thanks for posting that.
I don't supposed you happened to be recording a similar plot with a L1
only Ublox part at the same time by chance, did you? I think it would be
interesting to compare a 6T or M8 part to
Lady Heather can output RINEX (v2.xx and 3.xx files) for most receivers that
output pseudorange and/or carrier phase data. I have tested it with the Ublox
4T, 5T, 6T, 8T, F9P, and F9T receivers. Also the Venus RTK receivers, Trimble
NetRS, Ashtech Z12,, NVS08, Trimble timing receivers, and
The f9p is about 3 times better than the ublox m8t. Will post a plot
later..
Cheers
Michael
On Tue, 19 Mar 2019 at 9:00 am, Bob kb8tq wrote:
> Hi
>
> ….. and here I was wondering if it had ever gone out :) Glad it made it.
>
> No, I did not run any single frequency units beside it. It is much
The 74S140 (dual 4-input NAND) is the classic TI TTL 50-ohm driver.
They're still available in DIP & SOIC.
I'm currently waiting on some boards to arrive so I can try SN74LVC1G17
as a more modern replacement that's much cheaper and smaller.
Once I've proven it I'll do a separate thread to the
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