I wonder if it's smart enough to have a sanity check to determine
whether the line frequency is 50 vs. 60 Hz?
BTW -- I have an Ecodrive watch, but it's radio controlled (as well as
solar charging), so haven't seen any reference to this setting method
before.
John
On 4/20/2011 10:13 AM,
is no NMEA mode...
HTH,
Regards,
Jean-Louis
- Original Message - From: "John Ackermann N8UR"
To: "Discussion of precise time and frequency measurement"
Sent: Thursday, April 14, 2011 3:35 PM
Subject: Re: [time-nuts] GPS position averaging software?
Thanks, all, for
Thanks, all, for the suggestions. I'm playing with WinOncore12 at the
moment -- for some reason I'm not able to get the M12+ receiver into
NMEA mode so VisualGPS isn't usable.
I'll fuss more with NMEA mode this weekend, but is there any magic for
the ioformat switch? I've used the command fr
Just got a pair of GPS antennas on the roof and I'm interested in both
getting as accurate a position survey as I can, and in comparing the
performance of the two antennas -- one is a choke ring, the other a
Motorola Timing2000. I'm using an M12+ receiver.
I have TAC32 but am interested in ot
A couple of years ago I picked up a surplus Aeroantenna choke-ring GPS
antenna that I think was intended for surveying use. I finally got it
installed today and noticed that it has an arrow on the bottom
indicating that the antenna should be oriented with the arrow facing north.
I'm trying to
Dave, I haven't seen an actual Manson standard, but I do recall that one
was listed in an ancient Tucker catalog (from the early 80s). I'm just
now unpacking my library after our move, and should soon uncover that
catalog if I still have it. Let me know if you'd like me to scan the
Manson inf
Here's a measurement we did a few years ago on the HP 58535A:
http://www.febo.com/pages/hp_gps_splitter/port_1_hp_58535a_two_port_amp.png
John
On 3/4/2011 1:31 PM, Bob Camp wrote:
Hi
Ok, now it's pretty obvious the RF world near your GPS will be changing a *lot*
in the near future. Lights
On 3/4/2011 12:22 PM, Dan Rae wrote:
Does anyone know if there is a planned or upcoming replacement for the
Tapr TADD-1?
We're working on a very high performance distribution amplifier that
will replace the TADD-1 and also be available in a single-channel
version for isolation/buffer amp purp
Bert, first of all I'm really happy you're digging into this -- it's
been on my list of "projects for someday" for a long time!
One thing working in your favor is that the actual BFO frequency is way
down at audio; the BFO crystals at around 2 MHz are divided by 1000
before hitting the mixer.
All --
I hesitate to make pre-announcements, but TAPR plans to produce a very
high performance replacement for the TADD-1, as well as a single-channel
version for buffer/isolation amp use.
I'm just on the verge of ordering alpha boards for the single channel
version. I really can't hazard a
On 2/14/2011 11:45 AM, Joe Leikhim wrote:
Hi;
I would like to change my settings to receive only one daily digest. The
website is not clear on how to make the change for existing subscribers.
Can the administrator adjust this for me? Thanks
Unfortunately, the digest can't be changed per-subscri
Now that I'm getting settled in the Atlanta area, I thought it would be
interesting to set up a way for local time-nuts to communicate, share
resources (calibration parties, anyone?), and perhaps work on some group
experiments (anyone interested in creating UTC(ATL)?).
So, I've set up time-nut
You'll probably get better (and more interesting!) answers on the NTP
group/mailing list, but a first thought is that NTP takes quite a long
time to stabilize after startup.
From the jitter value below being larger than the offset, I'm guessing
you took this ntpq snapshot after only a few poll
FWIW, I have an FTS militarized Cesium that has an accelerometer as part of the
OCXO assembly to reduce vibration sensitivity. I'm told -- but can't document
-- that it was for the Navy and the idea was to counteract the effects of the
ship's guns. FTS engineers had a couple of PTTI articles d
All, this has drifted way off track and should have stopped many
messages ago. I really hate having to jump in here but I've been
getting well-justified private complaints.
Can we *please* try to keep things on topic???
John
J. Forster said the following on 01/01/2011 12:14 AM:
HNY,
I
I'm looking for rack mounting ears for Spectracom WWVB units, like the
8164 or 8170. If anyone has any they can spare, please contact me
off-list. (They're no longer available from Spectracom.)
Thanks!
John
j...@febo.com
___
time-nuts mailing list
On Dec 24, 2010, at 8:41 PM, "Tom Van Baak" wrote:
>> Lady Heather will display the date (but not fractional time) in MJD with /DM
>
> Anyone with a browser can try this one...
> http://www.leapsecond.com/java/nixie.htm
>
> Or the mobile phone version:
> http://leapsecond.com/m/mjd.htm
>
> /tv
Guys, I hate to do this but we're starting to get way off topic (as interesting
as I personally find radar history). Let's once again be considerate of the
1000 people who see each message posted here.
Thanks,
John
On Dec 20, 2010, at 6:54 PM, "Lee Reynolds" wrote:
> Hm, I suspect, Rob, muc
re the 3rd circuit down on the Wenzel page is
identical to the input circuit for the TAPR TADD-2 frequency divider. The
TADD-2 adds a transformer and load resistor. Schematic is in the manual
here:
http://www.tapr.org/~n8ur/TADD-2_Manual.pdf
-Bob
On Wed, Dec 8, 2010 at 8:46 AM, John Ackermann N
Wenzel has some discussion and circuits at:
http://www.wenzel.com/documents/waveform.html.
The Shera GPSDO made clever use of the input circuit of a 74HCT4046 PLL
chip for squaring.
John
On 12/8/2010 10:31 AM, jimlux wrote:
I'm looking for suggestions on a general circuit that can be us
is a function of the crystal
> physics. There is a specific impedance that you must use for
> a given bandwidth. Fortunately, it is easy to put transformers
> at the ports to convert to 50 ohms.
>
> Rick Karlquist
> N6RK
>
> On 11/15/2010 7:44 AM, John Ackermann N8UR wrot
I'd like to find a couple of 5.0 and/or 10.0 MHz crystal filters,
preferably configured for use in-line with 50 ohm coax.
I've done some googling but don't find anyone selling these as a stock
item. Do they exist? Any pointers would be appreciated. Used/surplus
is fine (even preferable).
Bert, I just approved your message, so it should show up soon. The reason for
the size increase is that the internet email format is 7-bit ASCII, so a binary
file has to be encoded down from 8 bits and grows as a result.
John
On Nov 13, 2010, at 3:32 PM, ewkeh...@aol.com wrote:
> Hi
> I give
All --
I am becoming very worried about the future of this list. TVB and I
have deliberately tried to maintain a light touch, trusting that the
positive value of the technical conversation here would outweigh the
inevitable noise.
However, it seems like self-restraint is a disappearing qual
t;
> Is there a source of crystals cut for temperature measurements?
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
>
>
> John Ackermann N8UR wrote:
>> Sounds like the way the HP 2804 quartz thermometer works. HP came up with a
>> special crysta
Sounds like the way the HP 2804 quartz thermometer works. HP came up with a
special crystal cut that was very linear with temp, and I suspect the hardest
part of your idea might be the linearity of the tempco of your crystal. But
you could characterize that and store in a correction table.
Jo
And for what it's worth, my digital scope is a TDS-1012 and I've been happy
with it.
John
On Oct 31, 2010, at 12:32 PM, "J. Forster" wrote:
> A couple of months ago, I bought a used Tek TDS 1002 for under $300. I've
> always been very skeptical about DSOs and just love 7xxx series analog
> un
Here's the page I wrote years ago on the split-shield antenna:
http://www.febo.com/time-freq/wwvb/antenna/index.html
Unfortunately, I never took any photos and the antenna is now in pieces
after a couple of moves.
I've also had good luck using an active voltage probe antenna to receive
both
We've never had a hard-and-fast rule, but in general the community seems
OK with (a) non-dealers making occasional postings about T&F related
items (i.e., excess or "housecleaning" items), and (b) commercial
sellers making *very* occasional postings about unusual items.
Periodic ads, or genera
The archives are at http://www.febo.com/pipermail/time-nuts/
I'm not sure why you're getting site safety warnings going there because
that's not an HTTPS (SSL) page, though the primary list management pages
are.
And regarding those warnings -- they are because I use a home-made
security cert
eld.
>
> Very strange stuff.
>
> Bob
>
>
> On Oct 15, 2010, at 9:20 PM, John Ackermann N8UR wrote:
>
>> I've regenerated the SSL certificate for HTTPS at febo.com. The new
>> certificate should be good for ten years, as I intended (but failed to
I've regenerated the SSL certificate for HTTPS at febo.com. The new
certificate should be good for ten years, as I intended (but failed to
accomplish) when I created the old one. It's still a self-signed cert,
so will throw a warning with your browser, but you can trust me and tell
the browse
bJason Rabel said the following on 10/15/2010 03:00 PM:
Why bother buying a cert? Just create a self-signed one (and you can make it
for like 10+ years)... It's not like he's selling stuff
from his website...
And that's what the old cert was. I will create a new one as soon as I
get a chance
Every now and then I get a request asking that I remove a post from the
time-nuts list archive because it was either meant for to an individual
rather than the list, or it inadvertently included personal information.
There is no easy way for me to remove a message from the archives; doing
so s
Re PIC programming -- if the volume is sufficient, Digi-Key will program
PICs. The set-up fee is enough that you probably want to do at least
50-100 units to amortize the cost, but it's not too bad. That's how we
handled the PIC for the TADD-2.
John
Heathkid wrote:
Stanley,
I'm not g
Steve, I'm sure there are several folks here with web sites or download
areas that could host the files. If no one else raises their hand, I
could put them on febo.com.
John
Steve Rooke said the following on 08/15/2010 10:53 AM:
Stanley and Nigel,
I have received the go ahead to distri
Didier Juges wrote:
I like the 3586 a lot, it's amazing what you can do with it. However, if you
send the audio (beat note) to a computer or other instrument, keep in mind that
the BFOs are not phase locked to the reference, they are just free standing
crystal oscillators, and they may be off
Here's data showing Doppler (and other effects) on WWV as received in
Dayton, OH over several days. I took this by reading an HP 3586C
frequency counter output via GPIB -- which seems to be a good technique
for long-term HF frequency gathering. You need to figure out a way to
remove outliers
All -- I've had an overwhelming response to my plea for advice. Thanks,
but no more need.
John
----
John Ackermann N8UR said the following on 07/23/2010 07:25 PM:
I'm going to exercise the administrator's prerogative and ask if someone
here who knows about IP network design w
I'm going to exercise the administrator's prerogative and ask if someone
here who knows about IP network design would be willing to contact me
***off list*** at j...@febo.com and provide a bit of consultation --
possibly via a quick phone call.
We've now moved into our new house/lab and I want
Sorry for the broadcast, but I wanted to get an update out to the users
of febo.com email services (including the various mailing lists hosted
here).
The good news is that my upcoming move from Ohio to Georgia shouldn't
disturb mail handling through febo.com.
The other good news is that I've
Stop by the TAPR booth! I'll be there most of the time (when I'm not
out snooping around in the flea market).
John
normn3...@stny.rr.com said the following on 05/12/2010 06:08 PM:
Who is headed to Dayton??
Any vendors with junk?
cu there! 73 de Norm n3ykf
___
box that isn't quite as good as (as in 40 db worse than floor) an HP 3048. Of course I'd need to buy a cheap synthesizer to go with the 3048 if I wanted to do the "any frequency" stuff at the 5115 level.
Bob
On Apr 7, 2010, at 7:04 PM, John Ackermann N8UR wrote:
I just t
I just took a look at the datasheets for the 5115, 5120, and 5125. .
The 5115 is the "base" model covering through 30 MHz and without a
cross-correlation capability. At 10 MHz input frequency, its spec is
-133 dBc/Hz at 1 Hz offset, and -147 dBc/Hz at >100 Hz offset (not
spec'd at greater of
Tom Holmes, N8ZM wrote:
Luis...
My wife is a great bargain hunter, and loves to come home and tell me how
much money she has saved on something she just bought. I've been trying to
get her to express the savings in dB$, but she just isn't going for it. Any
mention of the word logarithm sends her
For what it's worth, Corby, I've only ever seen or heard about that
sticker on 10811s that were in HP Cs or RB standards -- I think that
both my newer 5061A and 5065A have them. I have wondered whether maybe
that upgrade was for compatibility with the div2 board used in the
standards to get ba
I'd love to see the results of some well designed and controlled jitter
measurements. I did a bunch on the TADD-2 and a single-channel
prototype, but they weren't as rigorous as this group deserves. (The
short version is that the tests pretty consistently show jitter standard
deviation of les
o be able to get the board
in, and screwed in.
I'm probably going to be operating "open lid" for a while just to see the
LED status.
Dave
On Sat, Mar 13, 2010 at 10:29 AM, John Ackermann N8UR wrote:
Dave, the standoffs are threaded for a 4-40 screw, but I'll tell you a
secr
Dave, the standoffs are threaded for a 4-40 screw, but I'll tell you a
secret -- if you use the nuts and washers on the BNC connectors, the
board is held very securely without any need for the mounting screws;
I've frankly never bothered with them.
John
Dave hartzell said the following o
I don't think I agree with that, Warren. I'd view a primary standard as
an intrinsic one -- that is accurate by definition and doesn't need
calibration against another, higher level, source.
A cesium beam standard is based on the same physical phenomenon that
defines the second, so if it's wo
Sorry to all for the delay, but the results from the December Frequency
Measuring Test are available at
http://www.febo.com/pages/mvus-fmt/Dec2009/results.html
We congratulate WA4FJC, K5CM, AA6LK, K1GGI, and K9AYA for their first
place finishes (there were ties on three of the four bands). Th
You could also consider whether Gnuradio (http://www.gnuradio.org) could
do what you need. It has interfaces to the Linux sound system.
John
Bob Camp said the following on 02/18/2010 08:10 PM:
Hi
Ok, A bit more info:
1) Quadrature PLL using an RPD-1 DBM and a home brew lock box.
2) Wi
For Linux (and I think some other *nixes) check out Baudline
(http://www.baudline.com). It's free but not open source. It's a
general purpose audio spectrum analyzer tool, not aimed at ham radio.
John
Bob Camp said the following on 02/18/2010 06:18 PM:
Hi
Assuming I have a decent soun
Sal, what sweep time are you using on the scope? I believe the TBolt
PPS is only microseconds wide, so you may need to speed up the sweep
time to around 100us/div or faster to see it accurately. And you may
need to mess with delaying the sweep to get the pulse on the screen.
John
SAL C
Hi Raj --
You've already gotten some good answers. If all you want to do is
measure the frequency offset rather than characterize the stability, a
simple approach is to first get as close as you can by adjust for
minimum march of the 10 MHz signals across the oscilloscope, then use
either th
All --
While I have enjoyed the recent threads about benchtops, CFLs, LEDs,
etc., they really aren't on topic for this list, and we all need to
exercise some restraint.
While I think the incredible knowledge and inquisitiveness of this group
lead naturally to digressions, and those digressio
DMTD = Dual Mixer Time Difference
It's a system for improving resolution of frequency stability
measurement. You use a common low noise oscillator to separately mix
both the device under test and the reference source down to a low
frequency (usually between 1 and 100 Hz), then use a time inte
Oh, and I also put up 4x8 sheets of white perfboard all around my
workspace instead of drywall, and have various metal hooks to hang
cables from. That's been *really* handy.
John
John Ackermann N8UR said the following on 01/24/2010 01:19 PM:
An idea I really like, but haven't h
If RF measurement is your bag, and you're able to spend a couple of $K
(actually, <$2K if what I've seen recently holds), consider a
communications service monitor like the HP
8920A/8920B/8921/8924/8935/E8285 (all pretty much the same thing).
You get an RF generator, RF power meter, RX frequen
help
I can get! (I'm not a natural programmer, and C has always been
challenging for me.)
John
Magnus Danielson wrote:
John Ackermann N8UR wrote:
I see the makings of a great project here... a standard set of
routines for time/frequency/stability statistics. My only request is
to
I see the makings of a great project here... a standard set of routines
for time/frequency/stability statistics. My only request is to code
unobfuscatedly (sp?) to make translation into other languages easier
(e.g., I'd love a perl module with these functions, but am a complete
schmoe at figur
IIRC, the 15 MHz was derived from a divide-by-2 to get a 5 MHz square
wave, then selecting the 3rd harmonic via the filter.
John
Bob Camp said the following on 01/16/2010 12:40 PM:
Hi
U3 looks like it's at the output of the filter. U4A seems to be the power stage
that then drives the o
The deadline for submitting measurements in the December 2009 Midwest
VHF/UHF Society Frequency Measuring Test has now past, so the measured
frequencies with some back-up material have been posted at
http://www.febo.com/pages/mvus-fmt/Dec2009/results.html
The page is a work in process, but all
Bob Camp wrote:
Hi
I have a pile of 5334's in the shed. I'm getting the itch to pull them out
and see what they can do. I've always looked down on them a bit, since
5335's were always available for what I needed to do.
I've always liked the 5334s for both general bench use, and as TICs
where
Tom Duckworth said the following on 01/05/2010 09:10 PM:
Warren- No, a 100% error would be 40 GHz. Where did you get 40.4 GHz?
That would be 101% and of course 80 GHz is 200%.
Bruce- Of course you are right about the + symbol for 40.000 000 003 GHz
(+7.5 parts in 1E-11) but what would you cons
Tom Van Baak said the following on 12/29/2009 04:24 PM:
But, depending on the equipment you use, a phase noise
measurement (e.g., script L of f) doesn't require the source
to be long-term stable; you get pretty much the same phase
noise results in the first minute as you would a day or week
late
We're all set for the FMT beginning at 1500 UTC tomorrow.
A couple of minor changes from the earlier announcement:
* The 80M frequency will be around 3583 kHz, not 3577.
* The 2M frequency (within 50 Hz) will be 144.2743 MHz.
* We'll have a little more power on HF than we thought -- about 15
wa
Lux, Jim (337C) said the following on 12/23/2009 03:17 PM:
Typical (Cassini, MGS, etc., data from Sami Asmar) UltraStableOscillator (USO)
specs as used in spaceflight do about 1E-13 at tau =10 to 1000 seconds, 3E-13
at 1 second. Today, you can probably do maybe an order of magnitude better.
Just a reminder about the Frequency Measuring Test my group is going to
hold on Dec. 28-30.
If you're in the vicinity of Dayton, Ohio, we'll also be putting out a
signal on the 2M VHF band as well as the three HF bands. The 2M signal
will be in the vicinity of 144.040 MHz. If you're interest
Even though I finally got the actual ribbon cable used to interconnect
the -XO and -RB boxes, I was never able to get mine to actually act as
though it was disciplined. I suspect that either the XO or the Rb
free-run frequency was far enough off that it never locked up, but I ran
out of time (
I did something similar to my HP 5065A Rb standard, which had a 10811A
and a small plug-in card that was a digital IC doing a divide by two
followed by a simple LC filter. I picked off the signal right at the
chip input with a small cap and a piece of RG-174 that went to a buffer
amplifier (I
I have the data sheet here:
http://www.febo.com/pages/oscillators/100_MHz_Data_Sheets/
John
Corby Dawson wrote:
I bought a couple Bliley 100Mhz oscillators about a year ago, part #
NV26R891.
Now that I want to use them I can't find the pinout to identify which
pins are the EFC and power
Hi Corby --
Here's what the documentation for Option 120 on the FTS 4XXX series
cesiums says:
"Option 120 adds an accelerometer control to reduce the sensitivity of
the cesium standard against external vibrations in the range of about
0.1 Hz to several hundred Hz. The reduction achieved is more
For those interested in HF radio frequency and propagation measurement,
here is an announcement about a test transmission my local group in
Dayton, Ohio is going to run over the holidays.
More details below, but in short we're going to put out a low power
(about 5 watts) signal on three HF ham
Since Jim opened the door, I should mention that one of the projects
underway for the High Performance SDR group (http://www.openhpsdr.org)
is "Cyclops" which works with the existing HPSDR Mercury receiver board
to provide a DC - 1 GHz spectrum analyzer and tracking generator. Not
sure when it
The HP8569 is a good moderate-price choice that goes up to 18GHz. It's
new enough to have digital display, so you can do trace math like
normalization, and dump plots via GPIB. However, you cannot set
commands via GPIB.
The LO is stabilized (not synthesized) so frequency accuracy isn't too b
Check out the TADD-2 which does just that --
http://www.tapr.org/kits_tadd-2.html
John
Marco IK1ODO said the following on 10/27/2009 03:40 PM:
Anyone knows of a commercially available 10 MHz -> 1pps divider chain,
built or in kit form?
I know that it may be very simple or not, depending f
I'd be (happily) surprised if the NI libraries recognized Agilent
devices. I think they only support their own cards though.
There could also be a problem if you have both Agilent and NI support
libraries installed. I ran into this on Linux when I tried to install
the NI-provided drivers and
If you're not tied to Windows, I've written scripts in Perl under Linux
to get time and frequency data out of several HP counters (though not
the 5382). There is an open-source set of drivers and interface
libraries called "linux-gpib" that support virtually all GPIB cards and
USB dongles, and
Here's a reason why you might "want" (as opposed to "need"!) another
standard beyond the GPSDO.
An Rb or Cs is self-contained. The GPSDO relies on an external factor,
the presence of GPS. Holdover mode may be good to keep thing close for
a while, but over the long term the GPSDO without GPS
I'm leaving this response on the list since others might be interested.
The TADD-1 is back in stock at the TAPR office and I'm sure John is
working on catching up with back orders. However, he is currently en
route to Chicago for the upcoming TAPR/ARRL Digital Communications
Conference, so th
There hasn't been much discussion on the list about this idea. I know
that Timing Solutions (now Symmetricom) used to make -- or at least
advertise -- a "clean-up oscillator" that was a very low noise, very
high short-term stability BVA oscillator that would lock to your Cesium
reference. Wit
Marc Bury wrote:
Hi Matt,
A Hewlet Packard 3421A (Data acquisition unit) with option 20 (10 channel
multiplexer) and GPIB would fit your need withour emptying your wallet.
I can vouch for the 3421A -- nice, inexpensive box that is low power and
fairly painless to program. There are other HP
I got some from Digi-key a year or so ago. Unfortunately, I don't
recall the DK part number, but I recall I had to do a cross-reference
from the Cannon part number to another manufacturer (I think AMP) and
that's what DK had.
John
J. L. Trantham said the following on 07/18/2009 11:58 PM
I'm getting another flurry of messages from folks questioning why they
can't post to the list. An example of the error message is below.
When you get this message, it is almost invariably for one reason: you
are posting from an address that is not subscribed to the list. This
often results
I think several of us have an HP document on-line that explains at least
a bunch of the various models. My copy is at
http://www.febo.com/pages/hp10811/HP10811-Specs.pdf
John
Dave M said the following on 07/08/2009 08:02 PM:
On Wed, Jul 8, 2009 at 10:27 AM, iov...@inwind.it
wrote:
> D
We have had several lengthy discussions lately that have ended up
totally removed from precision time and frequency measurement (plumbing,
anyone?).
While a lot of us may find these threads interesting, please keep in
mind that the list has over 800 subscribers now, and that time-nuts is
adve
A bit further to Ulrich's point... one area where I had some problems
using serial/gpib converters in the old days, and I think that at least
early versions of the Prologix USB unit suffered from, is talking to
multiple instruments off the same GPIB controller. I never found a
satisfactory way
For really good adapters, I've had good luck with S.M. Electronics
(http://www.smelectronicsllc.com). They are pricey -- like $24-$36 each
for 18 GHz stainless N-to-something adapters, but I think on the whole
cheaper than Pasternack, and they often stock several grades (with
specified frequen
I took a look at the phase noise of a 3325B and as Jim said, the phase
noise is not great -- about -60 dBc at 1 Hz offset. An external
reference cleans up the close in (<10 Hz) signal, but beyond about 10 Hz
the synthesizer noice drowns out the reference; from the noise from 10
Hz to about 3 k
Yeah, I guess they really are 2U, but they're still thinner than the
other HP counters.
John
Hal Murray wrote:
Also, don't underestimate the 5334 counters. They are very capable,
though they don't have all the math and statistics functions of the
'35, they are only 1U in height *and have
Ed Palmer wrote:
By the way, I had a message disappear a week or so ago. I wonder what's
going on?
I'm not aware of any issues with the mail list system, but incoming
messages do go through a spam and antivirus filter, so it's possible
that some messages get caught in that. The filtering s
I picked up a really nice one with 10811A at the Dayton Hamvention for
$125, which was probably too good to be repeatable. Last year a friend
picked up three non-working but repairable for <$100 each. Probably
anything under $250 for a working unit isn't a bad deal.
Also, don't underestimate
Tom Van Baak said the following on 05/30/2009 03:44 PM:
... as long as you remember to use TI+/- mode.
For stuff like this I use plain old TI mode and just set the
UUT 1pps to lag the reference 1pps by a fraction of a
second, or maybe even just a couple of microseconds.
That way you get a sma
www works here, but we've had some other similar reports so there may be
some DNS strangeness. Thanks for letting me know, and I'll look into it.
John
Didier said the following on 05/23/2009 02:14 PM:
Actually, www.tapr.org is not there, tapr.org is...
Didier KO4BB
-Original Mes
Ackermann N8UR
Sent: Saturday, May 23, 2009 6:12 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] TAPR TADD-2 PIC frequency divider
The code is available at http://www.tapr.org/~n8ur/PIC_Code
in both source and object form. The "03-2009" version i
Magnus Danielson said the following on 05/23/2009 07:45 AM:
Since the TADD enclosure has two DB-9 cutouts, one nice option (which
I haven't tried yet) would be to wire the LED, the 5/10 MHz jumper,
and the ARM switch connections to a DB-9 and mount that in the
enclosure, then mount the LEDs an
The code is available at http://www.tapr.org/~n8ur/PIC_Code in both
source and object form. The "03-2009" version is what is shipping on
the current TADD-2s.
The "04-2009" version is a slight update from Richard McCorkle that
changes the way the ARM and SYNC LEDs work, and also allows selecti
Magnus, thanks for the nice comments!
Regarding the case, yes, the form factor generally matches the TADD
enclosure, but since that's a generic box we couldn't do much about the
LEDs or the ARM switch. My thinking was that the LEDs could be mounted
off-board if necessary, and I'll update the
The TADD-2 divider is now available for purchase from TAPR.
The TADD-2 accepts a 5 or 10 MHz input signal and generates 1 PPS
outputs (as well as other pulse rates). It has six low-impedance output
channels, each of which can be individually configured, and has a sync
circuit that allows the
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