Rich, stand by. I've been doing a *lot* of testing with higher-speed
pulserates on the u-blox F9T/M8T/M9N (as high as 20+ MHz) and will be
ready to report some results in a week or two, I hope. There are some
interesting findings.
And that testing underlies a new TAPR project I'm working
On 4/26/22 17:37, Graham / KE9H wrote:
For John A., or anyone comfortable answering.
When using the TICC in the default time stamping mode, is there any minimum
required separation in time required between the channel A and channel B
input events?
Is the TICC capable of handling two events
On 4/16/22 15:53, Matthias Welwarsky wrote:
John, what constellations did you have enabled during the test? Just GPS, or
also others? I usually run with GPS and Galileo enabled (and I avoid GLONASS,
it messes everything up). Can this make a difference?
I'm afraid I'm not certain. Normally, I
On 4/16/22 09:52, Matthias Welwarsky wrote:
Dear list members,
in 2020 John Ackermann published an evaluative survey of current day GPS and
GNSS receivers (URL below). I have a question about figure 26, which shows,
among others, the ADEV of a NEO-M8T against a Cesium reference, with
On 4/7/22 18:46, Lux, Jim wrote:
Wenzel is not some giant WalMart of oscillators, with forklifts going
hither and yon full of palletized ULNs - there are probably 50-60 people
there total, so odds are, you'll be talking to someone who actually has
touched (with gloves) your oscillator.
This
The FatPPS should be pretty stable when you trigger off the leading edge
of the output, since the delays are in silicon. But the trailing
(usually falling) edge of the output is a different matter as the pulse
width is controlled by a simple RC circuit and is likely to wander all
over the
On 3/26/22 13:23, Joseph Gwinn wrote:
It's the ever-present ship-hull vibration (under full steam) that is
being compensated for operational vibration, which falls largely
between ~10 Hz and 200 Hz. Big gun shocks cause rare noise bursts.
Also, the shock from a naval gun quickly degrades
On 3/25/22 19:22, ed breya wrote:
I'm a firm believer in using signal isolation transformers where needed
and practical. I've had plenty of issues with ground loop interference -
usually from line frequency harmonics - especially between different
pieces of equipment, but it can show up
You can stream data out of the receiver via either TCP or serial port
without storing to disk, so that's probably the best bet to save CF wear
and tear. I'm not sure if it's more difficult to turn the
But for now I'm doing as you suggest -- I have one "T00" format session
logging to disk in
Several time-nuts subscribers have recently reported that they've
received malicious email messages claiming to be from the time-nuts list
or from known members of the list. At first glance, the messages might
appear legitimate because they include text taken from old time-nuts
postings. But
Hi Skip --
I have had no trouble FTPing into two NetRSs from a Linux command line
ftp program. A couple of config settings might be important if you
haven't checked them:
Under "Internet/FTP" make sure "Anonymous FTP" is enabled with
appropriate access rights.
Under "Security" make sure
I've been working on frequency/stability measurements using the Trimble
NetRS and newer Mosaic-T dual-frequency receivers. Very early data
indicates that the NetRS does just about as well as the Mosaic, assuming
you are only interested in GPS and not GLONASS or the other
constellations the
On 2/27/22 6:56 PM, Bob kb8tq wrote:
These are *all* compare to a reference measurements. The floor will always be
set by that, one way or another.
Bob just stated a great truth that explains why and how we become
time-nuts -- in order to characterize an oscillator, you need another
I recently fired up my old Z3801As and ran across a similar problem.
Art Sepin helpfully reminded me that the old Motorola receivers'
on-board oscillators drift with time and after a long power off the
oscillator may drift so far that it can't lock. The receiver stores
calibration data in
That's a very good question, Hal. If you're talking about stability
testing, GPSDOs are a challenge because they (can) work well over a wide
range of measurement intervals -- you can have the short term stability
of a good OXCO, the mid-term stability of a mid-range Rb, and the long
term
Hi Joe --
The TimeLab software that's used with the 53100A is available from John
Miles at http://www.miles.io/timelab/beta.htm. There is a pretty
comprehensive users guide as well as a couple of app notes there,
although I don't think any of them document the .TIM file format.
However, he
Ackermann N8UR wrote:
I think the problem with the Z3801 is that it expects to see specific
handshake things at startup, in Motorola binary protocol. Dropping in a
random GPS will result in a "No GPS" error.
John
On 2/5/22 12:44 PM, Keelan Lightfoot wrote:
Depending on whoG€™s G
I think the problem with the Z3801 is that it expects to see specific
handshake things at startup, in Motorola binary protocol. Dropping in a
random GPS will result in a "No GPS" error.
John
On 2/5/22 12:44 PM, Keelan Lightfoot wrote:
Depending on who’s GPS chipset is being used, a fix
One thing I've seen on several OCXO and small Rbs is that the EFC pin is
internally wired in the middle of a voltage divider using two fairly
high value (>10K) resistors between Vref and ground. That ties the
varactor to the middle of the EFC range when no external tuning is
required. For
I'm replacing a dead Z3801 with a less-dead Z3805 (the Samsung labeled,
2 each 10 MHz and PPS BNCs, two DB25s).
Has anyone looked into whether that version of the 3805 has a PPS signal
on the DB25, or a mod to put it there? I've done some Googling and most
of the discussion of the Z3805
Hi Erik --
Unfortunately, your attachment did not make it through the list. That
sometimes happens when you put images "in line" or as HTML content.
Best thing is to send them as a "real" attachment.
Your question breaks into two pieces: (1) what's the resolution or noise
floor of the
Check Startech (https://www.startech.com). They have a range of RS-232
and similar I/O cards and at least the last time I bought one several
years ago, the chip emulated a 16550 UART and didn't seem to have more
jitter than any other serial board I'd tried.
John
On 11/6/21 12:32 PM,
chitecture-review
At about the 18 minute point he goes into the regions of PSRR. I poked
around so I can't vouch more all of the talk,
.
On Sun, 26 Sep 2021 18:21:36 -0400
John Ackermann N8UR wrote:
I got some interesting and unintended data today. I was measuring low
phase noise oscillators u
On 9/18/21 10:50 AM, Lux, Jim wrote:
LT3042 and LT3045 are your friend here. Excellent PSRR well up past 10
MHz.
If you need more current, you can just parallel them.
$6 each for the 3045 from Digikey
For best performance, take a look at the layout suggestions in the
3042/3045 datasheet,
In 2020 I did an extensive evaluation of the timing ability of the
u-blox LEA-M8F, NEO-M8N, NEO-M8T, NEO-M9N, ZED-F9P, and ZED-F9T. The
work was made possible by support from the HamSci consortium
(https://hamsci.org) under NSF grants supporting HamSci activities.
I was sure I'd posted about
IIRC Lady Heather comes with a TCP/IP example configuration that
connects to a couple of remote Thunderbolts, one of which is in Seattle.
Are you sure that's not what you're seeing?
John
On 7/8/21 10:00 AM, Admin wrote:
Chris,
Thanks for your comments.
However, how do you explain
If anyone who has a 5110A system would like this unit as a spare or
replacement, drop me a note off list. It's yours for the cost of
shipping. (Only those who can use it as intended need not apply... if
it were to be dissected and played with, I'd be the one doing it :-) )
John
On
And (thanks to TVB) -- that's the answer. It's from the 5110A
synthesizer driver, circa 1965.
On 6/6/21 1:28 PM, Poul-Henning Kamp wrote:
Magne Mæhre writes:
On 6/6/21 4:22 PM, John Ackermann N8UR wrote:
Looking through the junk box I came upon a metal box labeled:
Frequency
On 6/6/21 11:39 AM, Magne Mæhre wrote:
On 6/6/21 4:22 PM, John Ackermann N8UR wrote:
Looking through the junk box I came upon a metal box labeled:
Frequency Standard
05110-6014
Series 330
This eBay listing lists it as a 1 MHz HP frequency standard
https://www.ebay.de/itm/133759143331
Sounds a lot like the sort of thing you would see in an R-1051 or similar
military
gear from the late 1950’s or 1960’s. The labeling does not sound right for an
assembly out of a piece of HP gear.
Bob
On Jun 6, 2021, at 10:22 AM, John Ackermann N8UR wrote:
Looking through the junk box I came upon
Looking through the junk box I came upon a metal box labeled:
Frequency Standard
05110-6014
Series 330
It's about 4 1/2 x 5 1/2 x 3 inches and has odd voltage inputs -- -16V,
+10V, -12.6V along with a terminal for "meter switch" and 2 BNC jacks.
There are several adjustment points accessible
The RCB-F9T is definitely something *not* to emulate -- it uses an SMB
connector for the antenna (which no one else does) and it only has a 10
pin header (on 2mm, not 2.54mm spacing) that provides only one TIMEPULSE
output and no EXTINT inputs. Why u-blox decided that was a good form
factor
I'm interested in one, John
John
On 4/26/21 8:32 AM, John Miller via time-nuts wrote:
Hello everyone,
I’ve seen a number of messages lately that reference the TimeHat boards I put
together a couple of months ago, with lots of positive feedback, which I really
appreciate. The first run
3/29/21 10:14 AM, John Ackermann N8UR wrote:
That's probably a really bad idea. The phase noise from the TIMEPULSE
output is pretty bad compared to a "real" RF source, and by the time
it's multiplied up to 10 GHz you'll have more noise than signal.
Attached are some phase noise plots a
m again.
Many Thanks
Best regards,
Christoph
Message: 4
Date: Sun, 14 Mar 2021 14:51:58 -0400
From: John Ackermann N8UR
Subject: [time-nuts] Re: TAPR TIC: TimeLab mode question
To: time-nuts@lists.febo.com
Message-ID:
Content-Type: text/plain; charset=utf-8; format=flowed
Hi Matthias --
Hi Matthias --
I just took a look at the source and the "Debug" is meaningless...
stupid program error (missing a "break" in a case statement) caused that
to be printed when it shouldn't be. Easy fix.
But why you're seeing the bogus chC results will take a little more
investigation. I
Sorry about the intrusion. New systems always bring new challenges, I
mean opportunities.
___
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by injecting a
signal into the circuit. To do it properly, you need a setup in a microwave
anechoic chamber with transmitting antenna etc. The practical difference
may be small though, 1 or 2 ns ( sample of one antenna!).
Cheers
Michael
On Sat, 27 Feb 2021 at 11:42 am, John Ackermann N8UR wrote
You have to be careful comparing the LEA-M8F with other GPS units. It
does have low jitter because the "TIMEPULSE" signal is derived from the
TCXO which is locked to the GPS time mark.
But their claim of "essentially jitter free" depends on your definition
of "essentially" -- attached is a
practical system trying to get close to 5 ns absolute accuracy.
5 ns *relative* accuracy between two F9’s? I probably could buy that if the
appropriate
one sigma / on a clear day / with the wind in the right direction sort of
qualifiers are
attached.
Bob
On Feb 26, 2021, at 4:27 PM, John Acker
It's interesting that they talk about the F9 receivers offering 5 ns
absolute time accuracy. Does anyone know of tests confirming that, and
what sort of care was required in the setup to get there?
John
On 2/26/21 9:34 AM, Robert LaJeunesse wrote:
FWIW. No detailed content, and a
You can get custom-made decent quality cables with double shielded coax
(either RG-316D or RG-142) from China (where else?) for pretty low
prices. I am sure the cable isn't mil-spec but I cut a piece open and
the shield coverage, which is the main thing I worry about at HF
frequencies, is
Hi Attila --
A really good place to start would be the docs for the HP 3048 phase
noise system and associated app notes --
https://www.hpmemoryproject.org/technics/bench/3048/bench_3048_home.htm
is a good place to start. There's a *lot* of description there of how
the system worked.
In a
Just a thought, Paul --
If the teensy can generate an output that is accurate but jittery, you
could use a simple PLL to lock a crystal to that with a time constant
that smooths out the jitter.
John
On 10/31/20 1:47 PM, paul swed wrote:
Hello to the group. Wanted to update the everyone
FWIW, I have done PN measurements at 144 MHz with the TimePod and a
Frankenstein's laboratory lashup of 80 MHz ULN, HP doubler to 160 MHz,
HP mixer, and several amp and filter blocks. As far as I can tell, it
worked pretty well; at least, I could discern the PN difference among
several
Hi Attila --
Just a couple of corrections -- the "coarse clock" in the TICC runs at
10 kHz (100 us), not 1 kHz, and therefore the TDC never sees a
measurement interval longer than 100 us, not 1 ms.
More importantly, the chart in Figure 17 of the datasheet is for
operation in "Mode 1" of the
That's very interesting, Matthias! The lower noise floor intuitively
and the sqrt(2) improvement comes to mind, except that would apply only
if the two measurements were uncorrelated. Here, you have a common 10
MHz reference, so there's correlation.
But... the high-speed ring counters
On 9/26/20 9:33 PM, John Miles wrote:
One consequence of charge retention is that when the input signal is in the
first Nyquist zone, meaning below fLO/2, no net frequency translation occurs in
a sampler. There is no mixing going on, hence no reciprocal mixing either.
The sampler's
We know that phase noise scales with frequency, so if you multiply
frequency by 10 you get a 20 dB increase in noise.
What I don't fully understand is how that relationship works with other
than simple multiplication/division.
For example (and my real life concern), if I have an analog to
I've had good luck with Iota brand chargers for 12 and 24 volt... I
think they are "DCL" series or something similar. They are available in
various amperage and include a smart-charger circuit. I know Amazon
sells several models and the prices are in the $100-200 range. One of
their selling
Seconded! I don't have that set up on all my oscillators, but plan to
get there. I *do* have things set up so I can remove the 24V battery
bank for maintenance and run directly on the AC power.
BTW, I've standardized on using orange-black PowerPoles for 24V
(red-black for 12/13.8V,
Hi Donald --
Over a 10 second interval, you're really looking at the short term
stability of the oscillator in the GPSDO, which could vary be several
orders of magnitude. The GPS component will set the nominal frequency,
but the noise around nominal will be that of the OCXO.
A quite good
The annual Digital Communications Conference that TAPR co-sponsors with
the ARRL is coming up on Sep. 11 and 12 and will be available on the
Interwebs.
I'm forwarding the announcement here in an act of shameless
self-promotion because I'll be doing a presentation on the timing
performance of
Some answers below.
John
On 7/3/20 10:54 AM, w8ycm--- via time-nuts wrote:
New guy here needs help using the TAPT TICC and Timelab software
The TICC documentation, I am sure, is sufficient to those in the community,
but to someone who has only lurked around the edges, there are a few
What, the names aren't self-explanatory? :-)
TADD-1 -- broadband (0.1 - >30 MHz) analog distribution amplifier
TADD-2 -- 5/10 MHz 6 channel divider (1k to 1 PPS)
TADD-2 Mini -- 1/2.5/5/10 MHz to PPS single channel divider; very tiny
TADD-3 -- 6 channel PPS distribution amplifier (no divider)
On 5/14/20 5:07 PM, Bob kb8tq wrote:
> No, the cheap board houses don’t check for this stuff. They just build and
> send it
> back. If there’s a gotcha, you get it on the board.
I was pleasantly surprised last week when Seeed Fusion contacted me to
point out a problem where two vias were too
Check out "Tuxedo Park" by Jennet Conant -- it's all about Loomis and
his very interesting life.
John
On 5/12/20 7:24 PM, Bob Martin wrote:
> Does anyone know about Alfred Loomis and his
> early precision time measurements?
>
> According to the article in the link below, he
> was also
So, being a heartless butcher I opened up one of the HP 8-port GPS
splitters (forget the number) and removed the sawtooth filters so the
unit would pass both L1 and L2.
I found that to bridge the filter pads even the smallest cap I had (I
think 7pf) caused problems. I ended up making "gimmick"
Hi Chris --
Two possibilities:
1. Make sure you have TimeLab set for the correct mode (timestamp vs
time interval), for two channels, and for the right scaling factor (for
timestamps, scale by 1). Any of those can cause 1e0-type results.
2. If the two channels have timestamps that are within
I know this is getting off topic, but one more comment from me.
Solder flux is really important. I use nothing but "no clean" type for
SMT work -- very thin 0.015 no-clean solder (63/37 PbSn while I still
can), and a bottle of liquid no-clean flux with a needle dispenser. I
make sure the work
Hi Perry --
The circuit in the FatPPS is really simple and would be easy to duplicate.
Frankly, the reason we had to significantly increase the cost is because
we provide the board fully assembled (it's all surface mount parts), and
with the low volume we've had in the last few years, the
The TICC hardware design has features that make it possible to
synchronize and run several units from a common clock, allowing creation
of 4, 6, 8 or even larger multi-channel timestamping counters. The TICC
firmware has sort-of supported this capability as well. I think a
couple of people may
It's a feature not a bug. :-)
I was going to address possible out-of-sequence output in this update,
but after lots and lots of thinking and experiments, and discussions
with a few bright folks on this list, I've come to the conclusion that
there is no 100% reliable way to do sample ordering
I've just released an update to the Arduino firmware for the TICC; the
new version is 20200412.1. It, along with all the TICC source code and
documentation, is available at:
https://github.com/TAPR/TICC.
In addition to a few bug fixes and cleanups, there are a couple of more
noticeable changes
Hi Tobias --
Several years ago, with a bunch of help from Bruce and John Miles, I did
a very high isolation, very low phase noise buffer amp design that TAPR
sold for a limited run. It's built with surface mount parts but they
are user-friendly sized.
Details and schematic are at
ork better?
> I totally see that the error is somehow multiplied, but if my GPSDO is good
> (which I hope it is :-)) the error will still be very small - perhaps in
> the 1e-9 or 1e-10 region, so too low for my 5335A. Not?
>
>
> Tobias
>
> On Fri, Apr 3, 2020 at 5:34 PM John
I think the difference is between *mixing* or *dividing* down to a low
frequency.
When you divide, you divide the noise along with the carrier frequency.
When you mix, you "translate" the noise. If the signal bounces around
0.1 Hz at 10 MHz (awful, I know), when you divide to 1 PPS the noise is
One of my Sulzers on an oddball frequency seems, from the phase noise
plot, to have a crystal filter about 1 kHz wide -- see attached.
John
On 3/26/20 8:04 PM, Richard (Rick) Karlquist wrote:
> On 3/26/2020 3:03 PM, Perry Sandeen via time-nuts wrote:
>> Learned Gentlemen,
>> Both the HP 106
To answer Achim's recent question (that's also been posed by others,
neither Tom nor I are fans of "list scraping" sites like gmane.org.
They offer convenience, but they also divert searches from the canonical
archive at lists.febo.com to their own archives, which may not be
complete. Their
On 2/29/20 7:40 AM, Matthias Welwarsk wrote:
> For example, there's the TDC7200 itself. When I tested my design first, the
> measurements had a distinct relation to temperature, in the order of maybe
> 300ps/°C, but there's other stuff as well, for example, the 74ALVC74 in
> yours,
> the
Hi All --
I just had a report from a member that they were getting strange DMARC
errors on messages they posted. DMARC is a spam prevention tool that
really and truly messes up mailing list operation; I'll spare you the
details but it makes things very complicated for list traffic.
I just
If you've been missing the time-nuts list archives for the last week or
so, they have been turned back on.
The archives were hit with a denial-of-service attack and our hosting
company had to disable them because the traffic was crashing their
servers. Things have settled back down, so the
This is a long shot, but...
A long while ago TAPR obtained and then sold some printed circuit boards
that were intended to go into HP GPS antenna splitters.
The boards were about 1.5 by 3.5 inches and had all the parts mounted
for a 4 port splitter, but with no connectors attached. The part
On 11/22/19 12:21 PM, Tim Lister wrote:
> You probably don't need to wait that many days for the Final GPS
> satellite orbits; the IGS products page
> (https://www.igs.org/products)shows that even the real-time
> ultra-rapid products are a factor of 20x better in the orbit (but
> interestingly
ed there are some receivers that have an AGC built in. *IF* your
>>> receiver has one
>>> and *IF* you can get at it, that would be a great way to work this
>out.
>>> Indeed anybody
>>> who makes it past both of those constraints has a pretty unique
>device
Bob, this is a great summary, thanks!
One related question, especially with mixed systems -- how do you tell
if you have optimum signal level at the receiver?
Most show some sort of SNR or Cn value. What should we look for? What
are the indication of *too much* signal? One issue in particular
The limited knowledge I've obtained about survey antenna is that almost all use
a straight 5/8-11 thread. There are various 5/8 adapters available. I use one
to 1/4-20 to mount the antenna on a camera tripod.
On Oct 30, 2019, 3:17 AM, at 3:17 AM, Hal Murray
wrote:
>
>> I have two of these.
IIRC, there's a description in the 5065A manual about how to restore
the lamp if this happens, but I think the mechanism tends to occur
during long periods of storage, not during operation.
The small telco Rb's certainly have the flooding problem and there the
restoral methods are a bit more ad
Hi Greg --
The 5065A is a Rubidium standard and unlike Cesium units it doesn't have a
"wear out" mechanism. With a little TLC they can run indefinitely. While they
drift (very slowly), they have much better short term stability than a Cs and
so in some ways are more useful.
John
On Oct 23,
303-554-0307
>>
>> act...@hotmail.com
>>
>> "Peace is not the absence of violence, but the presence of Justice" Both MLK
>> and Albert Einstein
>>
>>
>> From: time-nuts on behalf of John
>> Ackermann.
Hi Corby --
I normally keep the 5065A running all the time -- it's usually set up as
the "house standard" and I tweak the frequency against Cs every few
months. You know more about its service history than I do. :-)
When it was working, I usually kept the 5061A running full time as local
time
FWIW, I designed the TADD-1 to have equal length signal paths for all six
channels.
73,
John
On Oct 23, 2019, 1:01 PM, at 1:01 PM, "Bill Dailey, MD, MSEng, MSMI"
wrote:
>I am working in a project that requires me to have very similarly
>phased
>10mhz references (beamforming).
>
>Previously I
branded by themselves rather than Anderson, but I can't tell if it's
> generic or made to their specs.
>
> On Sat, Oct 5, 2019 at 2:00 AM John Ackermann N8UR wrote:
>
>> Not a perfect solution, but for semi-permanent connections you can run a
>> small tie-wrap le
Not a perfect solution, but for semi-permanent connections you can run a small
tie-wrap lengthwise so the ends pass through the space between where the wires
on each end split and the body. Cinch it tight and the connectors won't come
apart without cutting the tie wrap.
On Oct 4, 2019, 7:04
ong with the signal wire/cable, so it's crimped between them. I don't
> know if that is the best way of handling that, but it's worked for me.
>
> On 04/10/2019 11:41 AM, John Ackermann. N8UR wrote:
>> West Mountain is a good source for all things PowerPole, but there are
>&g
I use lots and lots of Anderson PowerPoles and (mostly) West Mountain Radio
distribution units. I have different color codes for different voltages --
red/black for 12v, orange/black for 24v, green/black for 5v, etc. Primary 12
and 24 volt sources are big AGM batteries across float chargers.
On 9/17/19 3:33 AM, Dr. David Kirkby wrote:
> On Tue, 17 Sep 2019 at 04:00, Dana Whitlow wrote:
>
>> The nice thing about a Rb is that its short term stability (seconds to
>> minutes and perhaps
>> even longer) is much better than that of a GPS timing receiver. The bad
>> news is that Rb
>>
In theory, making a new TICC that ran on an RPi could provide
significantly more measurements per second, and more convenient I/O, but
wouldn't affect the quality of the results.
I've thought a bit about an RPi-based TICC, but it's a significant
redesign effort for limited gains.
John
On
The TICC uses an Arduino, not a Raspberry Pi. It would require both
major hardware and software changes to utilize an RPi.
On 8/14/19 1:28 PM, Perry Sandeen via time-nuts wrote:
> Yo Bubba Dudes!,
> I've just purchased a TAPR TIC module. Now the new Raspberry Pi Model B has
> just been
Having just been through the endian issue with a similar parser, I'll mention
that in Python the struct.unpack() function can handle endian swaps at tne same
time as it pulls binary data out of the message. It makes it pretty painless.
On Jul 13, 2019, 11:08 PM, at 11:08 PM, Mark Sims wrote:
I have several pages of schematics at:
https://www.febo.com/pages/hardware/AN_URQ_10/
but unfortunately not the full manual.
John
On 7/10/19 12:43 PM, Walter Shawlee 2 wrote:
> Does anybody have the manual for this old standard? mine works, but is
> a bit high, and needs internal
I just finished reading Einstein's Shadow by Seth Fletcher
(https://www.amazon.com/dp/B075WSLWFX/ref=dp-kindle-redirect?_encoding=UTF8=1).
It's a pop-science story about the development of the Event Horizon
Telescope and the quest to image a black hole. It was published just
before the recent
Just a note about possible spurious pulses with the TICC. The input circuit is
a 3.3v logic gate that's 5v-safe. Some PPS signals have much greater peak
amplitude than that (e.g., the HP atomic clocks).
Experience has shown that these pulses don't know have enough energy to damage
the input,
Star Case (https:www.starcase.com) is U.S. company (in Indiana) that sells
similar open-frame rack kits for very reasonable prices. I have several and
have been very pleased. They are available whatever height you want, with
depths of 20 to 30 inches. They have lots of accessories to trick
Other than the fact that his description of how the bombe worked is totally
wrong...
On May 21, 2019, 5:00 PM, at 5:00 PM, Mark Sims wrote:
>Everbody needs one of these...
>
>https://www.ebay.co.uk/itm/The-Covert-Bombe-Clock-from-Bad-Dog-Designs-Codebreaking-in-Secret/123775434764
>
I've decided it's time to make a bit of room in the basement, so am
selling some stuff. The list includes signal generators, spectrum
analyzers, power meter and sensors, and some "antiques."
There are a few things of particular interest to time-nuts and fmt-nuts:
several PTS synthesizers,
I have a large box of 8140 pods (well, I call them "taps"). They are
quite handy for stringing distribution points around a large room,
provided ultimate phase noise performance isn't required.
You *don't* need an 8140 main box to use these. All the 8140 does is
put 12V DC bias on its
I was running my newly-acquired Z12 (with 1999 firmware) overnight,
capturing RINEX data via Lady Heather, using Cesium reference.
This morning Lady Heather showed the receiver still tracking satellites
and giving time, but the lat/long/elevation were frozen -- lat and long
were correct, but
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