Re: [time-nuts] LH and Leo Bodnar GPS

[Wes]

I'll second this request.

Wes  N7WS

On 2/16/2018 1:01 PM, Jerry wrote:

Any chance that Lady Heather can be modified to connect to a USB
(non-serial) device such as the Leo Bodnar GPS?

  


Jerry NY2KW

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Re: [time-nuts] eBay GPS antennas

[Wes]

On 2/16/2018 11:31 AM, Stewart Cobb wrote:

...

For example, any AeroAntenna whose part number starts with "AT2775" is a
dual-frequency L1/L2 GPS antenna. AT2775-42 is a near-survey-grade antenna,
and one of them is available right now (item 263500294711) at a starting
bid of $20, after expiring yesterday with no bids at $25.

...

Look out for the shipping charge.
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Re: [time-nuts] GPS Jamming

[Wes]

This has been going on a long time.

http://defense-update.com/products/g/gps-ajr.htm

I was involved with testing this in the field years earlier.

Wes

On 1/26/2018 7:57 AM, Gary Neilson wrote:
Don't know if this has be posted before or not. Also don't know if this will 
affect timing info.


GPS Jamming 
<http://www.thedrive.com/the-war-zone/17987/usaf-is-jamming-gps-in-the-western-u-s-for-largest-ever-red-flag-air-war-exercise>


I am on the very edge of their coverage map.

Gary

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Re: [time-nuts] HP 3048 question: how to export graphs?

[Wes]

I can't speak to the 3048 but for screen captures I used to use the snipping 
tool, but have recently started using Irfanview.  You can run it in the 
background and with a single command (I use Ctrl+F11) can copy the full screen 
or window and save it instantly in a format and location of your choice or to 
the clipboard.


Wes  N7WS


On 10/15/2017 12:46 PM, John Miles wrote:

I don't believe there's a way to save images from within HTBasic, although there 
certainly should be.  I use the "Snipping Tool" accessory in Windows 7 for that 
sort of thing.  It probably exists in all versions of WIndows including 10, but who knows 
what they call it these days.

  If you create a shortcut key for the tool, it's easy to invoke whenever 
needed.   Hit ctrl-shift-C (in my case), wait for the tool to come up, and drag 
a box around the graph or other content to be cropped and saved.  The image can 
then be saved as a .PNG, .GIF, or .JPG, or pasted directly into a document.

The RESU files saved by 3048A.BAS are similar to the .res files saved by PN3048, and 
PN3048 can load them directly if you select 'All files' in the file-open dialog.   You 
can then save the graph or the entire window as a .PNG file.  TimeLab ( 
http://www.miles.io/timelab/beta.htm ) can also import them (File->Import .RES or 
.PNP noise data) and save images (File->Save image or .TIM file or File->Copy 
image to clipboard).  But if all you want is a .PNG, the snipping tool is much easier 
than dealing with any of this stuff.

-- john, KE5FX



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Re: [time-nuts] GPS Antenna Feed Line Decision

[Wes]

I'm dating myself again but when I was employed at Hughes Aircraft we had an HP 
salesman dedicated to servicing just us.  So most everything came direct from 
them or Wiltron.  I liked traveling to HP events with him.  Hughes had a miserly 
expense reporting process.  His was, "I count the money in my wallet before I 
leave.  I count it again when I get back.  The difference is my expense."


Wes

.  On 9/4/2017 2:26 PM, Bob kb8tq wrote:

Hi

A lot depends on just which outfit you buy your attenuators from. There
certainly *are* outfits out there that supply you just over 20 db RL when
the spec is 20. They also don’t charge very much for their attenuators ….

Bob



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Re: [time-nuts] GPS Antenna Feed Line Decision

[Wes]

Not being as nutty as many on this list I only skimmed the papers you provided.  
Interesting and I will stand corrected regarding the use of 75 ohm cable in 50 
ohm systems in critical situations.  In situations like my own, I'm not going to 
fuss about it.


I realize this is NIST, the 1384 paper was probably peer-reviewed, and I 
shouldn't question, nevertheless fools rush in.


In the block diagram of Figure 3 and the accompanying text, is described 
installing attenuators to increase return loss (RL) to what is claimed to be 40 
dB.  Forty dB RL is in the realm of precision calibration standards. 
(https://www.maurymw.com/Precision/Precision_Fixed_Terminations.php) and it's 
not trivial to measure on a single device.  Here we have a cascaded of two 
attenuators, two bias tees and a length of cable.


If these are COTS attenuators, their own return loss is unlikely to be 40 dB.  
In fact grabbing an old HP catalog off my bookshelf (I'm dating myself) I see a 
typical type N attenuator specified as 1.2 VSWR (~21 dB RL).  I went on a quick 
"shopping" trip looking for an L-band, type N bias tee.  I'll spare you the 
links, but typically they are also rated at 1.2 VSWR.


Perhaps NIST, with an unlimited supply of tax money, splurged and manufactured 
bias tees with >40 dB RL.  Maybe they did the same with the attenuators.  We'll 
never know because they didn't provide an equipment list or a measurement 
procedure.  They said nothing about the cable either, other than they started 
with RG-58 and replaced it with "better" cable.


A few words about cable, since that is what this discussion is all about.  
Cable, regardless of type and manufacturer, has its own RL, also known in that 
business as Structural Return Loss (SRL) See: 
https://www.belden.com/docs/upload/hdcarltp.pdf and 
http://www.keysight.com/upload/cmc_upload/All/E206COMPTEST_METHOD.pdf.


At least the authors admit, "Thus far we have seen little difference in the 
data."

Wes


On 9/3/2017 3:02 PM, Bill Byrom wrote:

For precision timing measurements, I would think that there would be
concern about the double reflections of a badly mismatched low loss
transmission line (such as using 75 ohm line in a 50 ohm environment).
The re-reflected signal will act similar to  multipath (as a delayed
aggressor) on all satellite signals equally. The impedance mismatch
delayed reflection aggressor could aggravate timing errors due to
changes in temperature or stress in the cable. Whether this is important
for you depends on how time-nutty you want to get.

See these papers:

Effects of Antenna Cables on GPS Timing Receivers:
http://tf.boulder.nist.gov/general/pdf/1384.pdf

Absolute Calibration of a Geodetic Time Transfer System:
http://xenon.colorado.edu/paperIrevise2.pdf
--
Bill Byrom N5BB



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Re: [time-nuts] GPS Antenna Feed Line Decision

[Wes]

On 9/2/2017 4:48 PM, Clay Autery wrote:

Thanks for the response...

Not sure why you and the other guy both recommended RG-6 75-Ohm cable
and F-connectors, when the nominal impedance of literally everything
else in the system is 50 Ohm, including the antenna and the HP GPS
Distribution Amp  And then adding N to F adapters?
As "the other guy" (I think) let me say that the impedance mismatch is 
immaterial and in my case I have one GPSDO with an SMA connector and another 
with a BNC and an antenna with an SMA.  So I "adapt" no matter what I do.  
Because I understand the cascaded noise figure equations, I know that I don't 
need an active distribution amplifier to feed just these two devices, so a $5.00 
"F" connector splitter is adequate. 
(https://www.markertek.com/product/201-232/2-way-2-4ghz-90db-satellite-splitter-dc-power-passing-to-one-port)

Doesn't make any sense unless one has $$ as a top priority, already has
a spool of RG-6 quad shield, etc...  but I specifically stated that $$
is not a top priority  Not really even in the top 5 or 10...

Then by all means you should use L-band waveguide. :-)

Wes

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Re: [time-nuts] GPS Antenna Feed Line Decision

[Wes]

This is just a cascaded noise figure situation.

The first stage is the antenna (preamp) which has 26 dB gain (assumed) and an 
unknown noise figure. Assume it's a dB or so. Let the second stage gain be a 
negative value equal to the cable loss and the second stage noise figure be 
equal to the cable loss in dB.  Assume a lousy 10 dB NF and 10 dB gain for the 
distribution amp.


If the cable loss is 5 dB then the cascaded noise figure and gain are: 1.26 dB, 
31 dB gain.


If the cable loss is 2 dB then the cascaded noise figure and gain are: 1.13 dB, 
33 dB gain.


I would use RG-6.

See: https://www.pasternack.com/t-calculator-noise-figure.aspx

The secret here is the 26 dB gain.


Wes  N7WS

On 9/2/2017 11:57 AM, Clay Autery wrote:

Having decision-making problems for the materials for my GPS main
feedline.  Going to use a TM LMR stock, just can't decide how big to go
with it...

26 dB 5vdc antenna on top of a 38 foot mast.  Feed will come down the
inside/center of mast and exit near the bottom, thence routed through a
window and to the GPS distro amp. Antenna will feed GPSDO, NTP Server,
Blitzortung System Blue station, and one other device TBD.

Just cannot decide how big to go with the antenna to distro amp feed...
Assuming 50 feet total (38' mast + 12 feet to amp in shack) @ 1800 MHz
(closest to 1725 MHz), here are the losses from just this piece
(ignoring the amp to device jumpers):

-240 = 5.45 dB XXX - too much loss?
-400 = 2.85 dB
-500 = 2.30 dB  XXX - too hard to find
-600 = 1.85 dB
-900 = 1.25 dB

Money not necessarily a consideration as this is a short run for a
permanent installation.  Don't anticipate ever moving the GPS antenna to
the tower.
For 900 and likely 600, likely would not be able to do it in one piece
as routing it out of the mast and into the shack would get complicated.
Would likely bring it out of the mast at the bottom with a right angle
connector, and then use a smaller diameter jumper for the last 12 feet.
500 is pretty uncommon stock wise and it and connectors are harder to find.

I already have the tooling for both 240 and 400... but I definitely
don't want to challenge ANY of the devices for signal gain.

So it mostly boils down to easy vs. more effort ($$ aside)  Is it
worth the additional trouble to move from -400 to -600 or -900?  To NOT
lose the 1-1.6 dB additional?

I'd appreciate your recommendation and reasoning. Thanks in advance!

73,



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[time-nuts] Latest Lady Heather

[Wes]

I asked about this before but got no response.

I know of John Miles' site where I downloaded v5 but I've seen a post by Mark 
Sims about further enhancements and wonder where I might get the latest.


Mark seems to have an "unlisted number."

Thanks,

Wes

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Re: [time-nuts] Anderson PowerPole (was Charles Wenzel GPSDO)

[Wes]

Hi Tom,

I said I use PPs but I don't really like them.  If you use a pair as a cable 
splice then yes, you can tie them together, but in the specific case I referred 
to, the connection on Elecraft radios, the mate is sticking out the back of a 
panel and it's impossible to knot the cable or use a zip tie.  I am certainly 
not the only one who has had issues with this.  And lest I be called an idiot, 
this is with a factory assembled and supplied pigtail.


Regards,

Wes


On 6/22/2017 12:19 AM, Tom Van Baak wrote:

Wes, Don,

I am quite surprised at the negative reaction to Anderson Power Pole 
connectors. I have found them the best DC connector out there. I have used them 
for a decade or two for all my DC feeds and have never had a problem: in my 
home lab, my car, even for my laptop charger. They are inexpensive, reliable, 
genderless (hermaphroditic) and easy to crimp. I use them for my 5V, 12V, 24V, 
and 48V supplies as well as my DC backup systems.

What on earth are you doing with them that causes them to disconnect? I mean, 
they are not meant for towing or lifting or rappelling. For critical 
applications there is a plastic gizmo that keeps them mated; or just use a 
square or figure 8 knot on the cables.

/tvb


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Re: [time-nuts] Charles Wenzel GPSDO

[Wes]

Although I've reluctantly bought into the amateur radio "standardization" hype 
of Power Poles and have a distribution panel with a plethora of them, I 
basically dislike them.  The ones on my Elecraft K3 and K3S pull out frequently 
when I move the radios and installing them is a PITA.


I never had such problems with radios with Molex connectors.

Wes Stewart


On 6/21/2017 2:36 PM, Brooke Clarke wrote:

Hi Chuck:

I'd replace the push on DC power connector with a high force Power Pole.  I 
can't count how many times one of these push on connectors has worked itself 
loose.

http://www.prc68.com/I/PowerPole.shtml



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Re: [time-nuts] GPS Antenna on Tower.

[Wes]

Mark,

Excuse my ignorance but where do I find this version?

Wes

On 6/20/2017 9:34 AM, Mark Sims wrote:

I just added the ability to calculate solid earth tides and the vertical 
gravity offset due to the sun and moon to Lady Heather.   The lat/lon offset is 
typically around +/- 60 cm per day.Vertical offset is around  +/- 180mm.  
Depending upon the day and where you are, the swings are not symmetrical around 
0.0



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Re: [time-nuts] GPS Antenna on Tower.

[Wes]

It was bright sunshine and 46 degrees C here in the desert near Tucson, Arizona 
yesterday.  It would take a lot of cooling to keep that solar collector (radome) 
cool.


Wes Stewart

 On 6/19/2017 9:42 PM, Thorbjørn Pedersen wrote:

http://www.sp.se/en/index/resources/GNSS/Sidor/default.aspx
Have a look at the best receiving antenna I know about.

The tower must have cooling tubes coiled around it because of the sun heating 
one side will make it bend away from the sun, and turn this way all day.
The cable and doom is also temperature controlled.

Best Regards

Thorbjørn W. Pedersen


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Re: [time-nuts] Smart Phone time display accuracy...?

[Wes]

My iPhone seems to be accurate to 5 minutes or so.  There are two of them in my 
house and they never agree.  My computer is saying 1:15 PM local time, my iPhone 
says 1:20PM


On 3/15/2017 7:32 PM, Mike Baker wrote:

Hello, Time-nutters--

Any thoughts on what the likely accuracy of smart phone time
displays might be?   I am thinking that the stacking of delays
along the path to its receive antenna plus any internal processing
delays would accumulate to some unknown degree.  Any
thoughts on this?

Mike Baker
*
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Re: [time-nuts] Vintage Frequency Measurement

[Wes]

On 2/13/2017 12:56 PM, Brooke Clarke wrote:


Wes:  Is this the patent for the IMPATT diode power amplifier?
https://patents.google.com/patent/US3931587

No.  As I recall the designer (or at least a prime mover) was a guy named 
Eisenhart.  The Hughes organization at the time had engineering done at Conoga 
Park and production here in Tucson.  I was in an auxiliary wing of the Conoga 
Park division located in Tucson to support production.  Engineering didn't think 
we were smart enough to build the stuff here and thought it should be built at 
Hughes Electron Dynamics Division in Torrance.  We of course thought otherwise 
so I was tasked to live at Conoga Park for six months to learn the system.  When 
I came back we broke I don't know how many rules to build two prototype 
transmitters on the factory floor using hourly assembly workers.  Lotsa fun.


BTW, you and I have met.  It was 27 years ago almost to the day! (February 15, 
1990)  I know because I still have the trip report I wrote after visiting FEI to 
review your design for an automatic test position for testing detector diodes.  
In a serious amount of understatement, I described you as "a very capable 
individual" but one who is spread too thin.


Wes

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Re: [time-nuts] Vintage Frequency Measurement

[Wes]

This reminds me.

Many years ago the Titan Missile sites around here in Tucson were being 
decommissioned.  The people at Davis Monthan AFB who maintained them were going 
to be out of work but had an opportunity to bump into something else on base if 
they got some more training.  I and a coworker, who had quit a tenured position 
at the U of A, were both teaching part time at the local Jr college.  The AF 
approached the college to request a class be developed to help their people 
prepare for the new work.  The college in turn approached my PhD friend.  He was 
happy to do the lecture part of a course but wanted nothing to do with teaching 
lab work.  He asked me to share the job with him.


I don't remember all of the particulars but I do remember that after each lab 
session the AF folks removed all of the lab gear from the work benches and 
locked it away in storage cabinets before wiping down the benches and mopping 
the floors.  This included unplugging an HP-5245L and tucking it away.  I 
admonished them about this practice and actually taught them about crystal 
aging, etc and the need for time for stabilization. This was years before GPS.


I had one woman Sgt confess to me that when she went to a silo to check some 
frequency or the other, she was supposed to use a piece of equipment that took 
hours to stabilize.  From the sound of it it was some WWVB phase comparison 
equipment.  Instead of this process, she grabbed the frequency counter from the 
lab, threw it in the PU and hauled it 50 miles to the missile site, plugged it 
in and tweaked the widget using the counter.  I had visions of a Titan Missile 
targeted to hit Vladivostok landing on Tokyo instead.


Wes Stewart


2/12/2017 7:31 PM, Bob Camp wrote:

Hi

If you look at a typical BC-221 in use, it goes from “calibrated” in a nice 
warm hut to the back
of a jeep. It heads out to an ice cold flight line and the switch turns the 
batteries back on again.
It bumps in and out of a batch of B-17’s setting each one up for the day’s net 
frequencies. You
would be doing very well to hold 50 ppm under those circumstances. That was 
indeed adequate
for the purpose.

Bob



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Re: [time-nuts] New stuff in my Tindie store

[Wes]

Most of the citizens of the state of Arizona are smart enough to know that you 
can't actually save any daylight with daylight savings time.  Hence, we remain 
on Mountain Standard Time.


The Navajo Indian Nation, whose territory spans parts of three states, including 
northeast AZ, decided to use DST.  However, the Hopi Nation, whose territory is 
entirely within the Arizona portion of the Navajo Nation, stays on MST.


The polygamist Mormon town of Colorado City, Arizona and Hildale, Utah is 
literally bisected by the state line.  Utah observes MDT so part of the town is 
MDT and the other part is MST.  I reality, it's my understanding that the whole 
town uses MDT.


(For such a tiny place, Colorado City has made a lot of news.  It was once known 
as Short Creek.)


On 12/26/2016 10:22 PM, Mark Sims wrote:

Ahhh, the subtle wonders of time zones and DST changes...  Heather lets you set 
your time zone offset down to the second, and does not range limit the offset.  
If you want UTC +987:65:43 it's yours!   There are a surprising number of 
places on with weirdo time zones.

I tried to find a manageable, self contained way to automatically calculate the 
time zone from lat/lon, but that's a losing battle.  Even getting it off the 
net is rather problematic.  I've thought about implementing a last-ditch 
emergency back-up plan of basing it on (longitude/15) but decided that was too 
un-time-nutty.

Heather has standard DST rules for USA, Europe, Australia, and New Zealand 
(assuming it hasn't yet gone the way of Atlantis).  But since DST rules can 
change with the stroke a a politician's pen, you can specify a custom rule.  
The one current DST limitation is the time must change at an hour...  that 
would be easy enough to change.




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Re: [time-nuts] Man with too many clocks.

[Wes]

On 11/4/2016 12:34 PM, Hal Murray wrote:

kb...@n1k.org said:

The only practical way to set the 10811 or 10544 is with a >= 10 turn pot on
the EFC. I never have worked out just why there are so many instruments that
don’t have a pot on the EFC.

How would temperature effect that?  For that matter, how does temperature
effect the typical mechanical capacitor?  Does anybody play fancy tricks to
cancel out the mechanical motions?  (like the mercury pendulum - as the
pendulum rod expands the mercury expands in the other direction to keep the
CG the same)

The variable tuning capacitor in one of the military "frequency meters" (I 
forget which one, BC221 leaps to mind) had a small disk on an adjustment screw 
that worked against a bi-metallic strip "diving board" to make a temperature 
sensitive trimmer capacitor.  I suspect, however, that it functioned more to 
compensate the inductor than the variable capacitor that was very robust.


Before synthesizers, I built a VFO for a homemade receiver using one of these 
cannibalized from a freq meter.


Wes Stewart, N7WS
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Re: [time-nuts] Temp/Humidity control systems?

[Wes]

On 10/30/2016 10:18 PM, Bill Hawkins wrote:

Think of the fun you'll have determining the heat flow model constants
for the system. In particular, there's no air flow sensor because they
are expensive. You'll need to determine the relation between fan speed
and air flow.
You can buy an automotive mass airflow sensor on eBay for a few dollars.  The 
flow rates may or may not be appropriate, but they're out there.

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Re: [time-nuts] Temp/Humidity control systems?

[Wes]

On 10/27/2016 6:43 AM, Ron Bean wrote:

BTW some of us are more sensitive to humidity than others. I can't tell
you the RH of a room, but I can tell you when it's too dry for comfort.
I want it as close to 50% as I can get it without growing mold on the
walls. Some "experts" claim that 30% is good enough for anyone, but
they're wrong.

Clearly, you don't live in Arizona :-)
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Re: [time-nuts] Has anybody checked this? GPSDO in kit

[Wes]

On 10/22/2016 9:22 AM, Chris Albertson wrote:


You have to remember what this thing replaces.   In ham radio, some people
are using vacuum tube oscillators with mechanical variable capacitor
tuning.  Maybe some advanced rigs use gear drive on the capacitor shaft to
allow more exact tuning  This Si chip is considerably better then 1940's
technology.
I guess my WW-II vintage BC342 receiver (that I started with and still own) was 
"advanced".  It has an extensive gear train for tuning.


On the other hand my two Elecraft K3s are full of DDS and microprocessors but no 
variable capacitors.


Flex radios, are direct sampling SDR and newer ones offer GPS stabilization.
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Re: [time-nuts] Need Time Help

[Wes]

On 10/5/2016 7:40 PM, Chris Albertson wrote:

There was a time when HAMs where the ones pushing radio technology
forward.  Maybe these guys are doing that and building a digital EME
network on VHF?  We don't know.
Actually, we do know.  Regarding my earlier comments, I believe at the time 
(mid-1970) those of us pursuing EME _were_ pushing the technology forward.

We can guess but typically when you start wanting precise time
synchronization it is because of something like TDMA (time division
multiple access) to a shared resource.
Not so.  What is now common is the use of "JT" modes.  JT modes have a number of 
variations but what they have in common is they were developed by Nobel Prize 
winner, Dr. Joe Taylor, who has freely given the software to the ham radio 
community.  See: http://physics.princeton.edu/pulsar/K1JT/JT65.pdf


Although I personally ceased pursuing this activity many years ago, there remain 
some of us, who are not Luddites, but still believe that "Deep Search Decoding" 
is a questionable practice, no matter how it is rationalized.


Nevertheless, the referenced paper should explain the need for precise 
timekeeping.

On Wed, Oct 5, 2016 at 9:47 AM, Wes <w...@triconet.org> wrote:


If you are working "real" EME where you, and not a computer plus lookup
table, are coping the signals, none of these precise timing issues exist.

Wes  N7WS



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Re: [time-nuts] Need Time Help

[Wes]

If you are working "real" EME where you, and not a computer plus lookup table, 
are coping the signals, none of these precise timing issues exist.


Wes  N7WS

On 10/5/2016 6:18 AM, Peter Torry via time-nuts wrote:
I must admit to being rather puzzled at the sub microsecond timing requirement 
as I use ntp to set the W7 clock in my computer and have not had any issues. 
In fact less than one second is OK for the usual two minute periods that are 
required to allow for the Faraday rotation. Although I use a GPSDO for a 
frequency reference I find JT software reasonably tolerant of frequency.  As I 
may be missing something I would welcome observations on how important the 
period timing requirement is, you never know I might get more contacts.


Regards

Peter


On 05/10/2016 12:50, Graham / KE9H wrote:

For the group. This ham is trying to work EME. Earth-Moon-Earth propagation
path. Aka, "moonbounce."

He is trying to time synchronize a system, where the other station he is
communicating
with can be any other place on the Earth that can also see the Moon.

So the system time sync is for a little bit tougher case than a local area
network.

--- Graham 


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Re: [time-nuts] Measuring phase with an HP 3456A?

[Wes]

On 10/1/2016 6:54 PM, Bob Stewart wrote:

OK, I give up.  My participation in this thread is over.
Bob
  -

Why?

You asked some questions and several people have tried to help you. I think one 
issue is that you mention measuring phase angle with a voltmeter and people 
naturally think "phase detector."  An example is Slide 20 on page 213 in this 
reference: http://hpmemoryproject.org/an/pdf/HP-3048A_cal_man.pdf  (I happened 
to have worked with Terry Decker, one of he coauthors, at Hughes Aircraft a long 
time ago)


As Bob Camp said earlier, both sources are not on nearly the same frequency but 
exactly the same frequency.  If you are thinking of measuring something other 
than this, then we have a semantics issue and need clarification of what it is 
you want to know.


Regards, Wes Stewart
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Re: [time-nuts] Measuring phase with an HP 3456A?

[Wes]

On 10/1/2016 5:13 PM, Bob Stewart wrote:

Hi Bob Albert,

  Completely eliminate the use of the term "DMTD".  I didn't post that.

Actually you did in your first post.

   "I've been spending a small amount of my time looking into making a sort of
   hybrid DMTD with a pair of DBMs"

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Re: [time-nuts] Clean 10 MHz ref

[Wes]

On 9/14/2016 2:59 AM, David J Taylor wrote:

It is non-trivial to set other than a few embedded frequencies with the existing
software.  There has been a veiled promise of improved software that remains
unfulfilled.  It is a GPSDO, although the internal oscillator is a TCXO, not an
OCXO.  Mine runs on even a laptop USB port.

Wes
==

Folks,

Mine's running of a standard PC USB port, and the power consumption measures 
between 220 and 240 mA.


With the supplied software (mine dated 2016-May-10, but that may have been the 
install date) setting the frequency is simply typing in the frequency in Hz, 
clicking "Find" and clicking "Update". I've tried a whole variety of random 
frequencies (e.g. 123.456789 MHz) and the device locks within a few seconds.


One limit is that the second output frequency needs to be related to the 
first, as far as I can tell.


Cheers,
David


True for the first frequency.  The second statement may or may not be true, it 
was not clear in the original description of the device.  When I wrote Leo and 
asked about a specific second frequency he did a manual calculation and sent me 
the parameters. From another email reply:


   "Sorry, did not catch your email first time.  Thank you for your custom!

   The numbers are internal settings of PLL chip Si5328 and you can find more
   details here:
   
https://www.silabs.com/Support%20Documents/TechnicalDocs/Si53xxReferenceManual.pdf

   You can set other frequencies just by typing them into Output 1 box and
   clicking "Find"  This will find and program the new frequency.

   If you want two separate frequencies at the same time it gets a bit tricky
   and often need manual setup.  In such case let me know what combination you
   would like and i will try to find the correct settings."

While this is process is helpful, it is hardly convenient and frankly me 
deciphering the doc without a Rosetta Stone isn't going to happen.


Wes, N7WS

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Re: [time-nuts] Clean 10 MHz ref

[Wes]

On 9/13/2016 12:42 PM, Nick Wagner wrote:

Hi to time nuts.. This source has been mentioned before. I purchased a unit
several months after seeing it recommended. It is made by Leo Bodnar
Electronics in England. It is

The simplest way to get a very clean 10 MHz sq wave. I have only observed
the 10 MHz on a scope .. have no other reference to check it. Either phase
noise or adev, but data sheet

Promised very good phase noise. Mine cost $224.98 USD. Including postage It
comes with an ant you can just hang out the window and is powered by USB.
You need to use a USB Charger, because the PC USB port may be too weak

Other frequencies may also be produced(not a trivial task) .. It has two
outputs which may have different frequencies.. It is not a GPSDO in the
normal sense .. I think it is phase locked to the L1 carrier.

Nick Wagner ..  KB6PL
It is non-trivial to set other than a few embedded frequencies with the existing 
software.  There has been a veiled promise of improved software that remains 
unfulfilled.  It is a GPSDO, although the internal oscillator is a TCXO, not an 
OCXO.  Mine runs on even a laptop USB port.


Wes




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Re: [time-nuts] DIY VNA design [VNA-Nuts?]

[Wes]

I agree.

On 8/22/2016 2:44 PM, Attila Kinali wrote:

On Mon, 22 Aug 2016 14:20:59 -0400
Bob Bownes  wrote:


Just finished creating it at groups.io

*https://groups.io/g/svna *
and sign up. :)

Is there any advantage of using groups.io compared to a traditional
mailinglist? If not, I would prefer a traditional mailinglist.
But maybe I am just oldfashioned :-)

Attila Kinali



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Re: [time-nuts] DIY VNA design

[Wes]

I built an original N2PK, that interfaced via a parallel port.  I did a minor 
upgrade that changed to an improved DAC.  I still have a Win XP laptop with a 
parallel port so can still use it.  Later it was refined to USB but I never 
upgraded, although I still have the unpopulated circuit boards for the later 
configuration.


The reason for not finishing the project, other than time, is the fact that I 
bought the other ANA under discussion, the VNWA-3.


As someone who started using a grease pencil on the CRT for "calibration" of a 
waveguide reflectometer, graduated to an HP8410 then an HP8510, I never cease to 
be amazed that I can hold something with similar accuracy (albeit less frequency 
range) in the palm of my hand.


Wes

On 8/20/2016 11:37 PM, Bob Albert via time-nuts wrote:

Well that's a start.  Thanks for the link!  I would need more information, as 
this project goes into areas that are new to me.  And there is no clue as to 
the cost of construction.
But I'll study what's there and if nothing else, learn something.
Bob
  


 On Saturday, August 20, 2016 10:46 PM, Orin Eman <orin.e...@gmail.com> 
wrote:
  


  To 60MHz: http://n2pk.com; PCBs available here: http://www.makarov.ca/vna.htm
To 500MHz, lower dynamic range to 1.3GHz: 
http://sdr-kits.net/VNWA3_Description.html
OK, so the latter isn't build it yourself anymore.
I have version 2.6 of the latter and it works really well to about 575MHz.  
Traces can get noisy after about 575MHz.
Remember these VNAs are only as good as the calibration kit you use with them!
Orin.

On Sat, Aug 20, 2016 at 9:46 PM, Bob Albert via time-nuts <time-nuts@febo.com> 
wrote:

I was interested in this, but my needs are mostly below 100 MHz.  I wonder what 
could be done similarly for this lower range...
Bob


 On Saturday, August 20, 2016 8:54 PM, Richard (Rick) Karlquist 
<rich...@karlquist.com> wrote:


  Another great posting, Attila.

When I was with Agilent, we looked at all kinds of
simplified network analyzer architectures, and I
would have to say the author is really well informed.
One issue he doesn't seem to be aware of is that the
ADL5801, when driven single ended, has some quirks
below 100 MHz that I discovered experimentally.
(The data sheet is silent on this).  IMHO, it
would be worth 7 Euro's to use a balun, however,
I would like to know the part number of this
supposed component.  I am not so sure about MCL
actually covering 30 MHz to 6 GHz in the same
balun.  Sometimes their advertising is confusing,
and when they say .03-6 GHz baluns, they mean
that the range can be covered in several bands
by several model numbers.

Still, quite impressive work by an individual
practitioner.

Rick

On 8/20/2016 7:19 PM, Attila Kinali wrote:

Moin,

I stumbled over a new open hardware/source VNA design:
http://hforsten.com/cheap- homemade-30-mhz-6-ghz-vector- network-analyzer.html

Unlike other designs out there, this one is very well done and has very
little room for improvement, without increasing the price considerably.

About the only things i would do different is to use two receiver
channels, one fix connected at the TX source to be able to do a
difference measurement between TX and the RX channels and thus
improving precision. And the other would be to use a dual ADC
with an FPGA for the data processing, again in order to increase
performance.

But as I wrote, both changes would increase complexity and price.

Other than being a well thought through design, the website also
explains all the big design choices and why this or that has been
done instead of one of the many alternatives. That alone makes it
worth reading, IMHO.

 Attila Kinali




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Re: [time-nuts] Low cost SDR suitable for phase noise measurement?

[Wes]

Where can I find this mod?

On 8/11/2016 11:36 AM, Brooke Clarke wrote:

Hi Bob:

The SDR-IQ has a lower frequency limit of 500 Hz.
http://www.prc68.com/I/Bats.shtml#SDRIQ

There is a mod that replaces the on board 66 MHz oscillator with one locked to 
10 MHz.




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Re: [time-nuts] OXCO Spurious Output at Line Frequencies

[Wes]

I retired in 1999 so it's been a long time since I used one, but I don't recall 
ever seeing a device measured using an HP 3048 system that didn't exhibit line 
frequency (and harmonic) spurs.


See the "live" plots at the end of this page: 
http://hpmemoryproject.org/news/3048/hp3048_01.htm


Wes

On 7/12/2016 3:44 AM, Martyn Smith wrote:

Hello,

I have a customer who is measuring the phase noise of my 10 MHz ultra-low phase 
noise frequency standard.

He is seeing spurious signals at line frequencies (50 and 100 Hz as we are in 
Europe) at a level around -130 dBc.

My opinion is that it's impossible to get much better than that.  Even running 
on batteries make little difference, since the equipment is in a test rack with 
AC signals everywhere.

Even the £50k R test set he is using only quotes a spurious spec of -90 dBc.

What experience does anyone have here?

Best Regards

Martyn


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Re: [time-nuts] The home time-lab

[Wes]

I have for years powered much of my ham station with a 90AH SLA maintained with 
a homemade "smart" charger. I used an analog Astron 35A power supply (RS-35M) 
for its raw DC and series pass transistors with its regulator board replaced 
with a (now obsolete) AA Engineering smart charger board.  This used a uC3906 IC 
for control.  Capacity wise this was actually overkill for my application as the 
charger could supply the total load.


Although many years ago I worked for the founders of Iota Engineering I have no 
interest in the company other than as a satisfied customer.  That said, if 
someone wants to pursue something similar I can recommend their power supplies 
with their "smart charger" modules.  (http://iotaengineering.com/power.htm)



On 7/8/2016 12:08 AM, Hal Murray wrote:

i...@blackmountainforge.com said:

There is a company in the USA that manufactures a product called
BatteryTender - excellent float charger and maintainer. Costco sells them
for $40

How do those types of chargers work when there is a load?

It's not the typical "float" there is also significant current going to the
thunderbolt.



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Re: [time-nuts] I thought GPS repeated every 12 hours (-2 minutes)

[Wes]

On 5/24/2016 7:26 PM, David wrote

   The 2 meter
directional antenna I ultimately designed was good enough to not only
track airlines by their reflected RF, but it could see reflections and
shadows from nearby objects like street lights and trees which
ultimately limited outside performance testing.
As someone who operated amateur radio moonbounce on 2-meters back in the day 
when you actually had to hear the signals, I find this really hard to believe.


Wes  N7WS
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Re: [time-nuts] Simple solution for disciplining OCXO with 1 PPS

[Wes]

A cleaver design, but the OP wanted 1pps.  I have the Leo Bodnar GPSDO.  It too 
is a nice frequency standard, but it doesn't know what time it is.


On 5/24/2016 9:53 AM, Graham / KE9H wrote:

If you want an "existence proof" for a simple, mostly analog, a few digital
counters, no software or microprocessor GPSDO, look at the "Miller" GPSDO.
He designed it for his own use, then put it into production because of
demand for a simple, cheap GPSDO.  It has been characterized, and works
well for the simple circuit.

The schematics are published, since it started as a hobby project.

http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm

http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm

You can buy his, or build your own with his design as a starting point.

He does use a GPS with 10 kHz output to simplify some of the timing and
integration issues Bob referred to.

--- Graham

==



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Re: [time-nuts] GENIUS by Stephen Hawking (PBS TV), with 5071A cesium clocks

[Wes]

Congratulations Tom,

I'm a lurker here and learn something every day.  I'm also in Tucson and have 
spent a lot of time on Mt. Lemmon so that hook is really cool.


My recorder is all set.  Locally on PBS at 9PM.

Wes  N7WS

On 5/17/2016 7:50 PM, Tom Van Baak wrote:

The TV show is tomorrow, Wednesday evening. 8/9 PM, or something like that.

Here are fresh web pages with background information, photos, and plots:

http://leapsecond.com/great2016a/

http://leapsecond.com/great2016a/photos.htm

I have no idea how minor my role is in the actual TV episode, but if nothing 
else, the above two pages will share some time nuts sort of details of the 
clock experiment itself. If you have any questions let me know.

/tvb

- Original Message -
From: "Tom Van Baak" <t...@leapsecond.com>
To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com>
Sent: Friday, May 13, 2016 12:00 PM
Subject: [time-nuts] GENIUS by Stephen Hawking (PBS TV),with 5071A cesium clocks


Fellow time nuts,

Here in the US, a new six-part TV series on National Geographic / PBS starts next 
Wednesday, May 18th, 2016. The title is "Genius by Stephen Hawking" and episode 
1 is: Can We Time Travel?

Having not seen it yet, I can't make a promise of its "SNR" (Science to 
Nonsense Ratio). It might be quite educational, or at least, very entertaining. And I'm 
definitely going to watch it with my family.

So why do I mention this?

Well, I spent most of December 2015 and January 2016 working with the UK-based 
producers of the show -- in order to pull off another Einstein 100th 
anniversary, general relativity, cesium atomic clock, gravitational time 
dilation experiment. The location chosen was 9000+ foot Mt Lemmon, near Tucson, 
Arizona.

The Hawking series covers a wide variety of topics, and this atomic clock bit 
is just one very small part. They were inspired by the DIY experiment I did ( 
http://leapsecond.com/great2005/tour/ ) and they wanted to create and film 
something similar. So I offered to help. Scenes with (me? and) my 5071A cesium 
clocks and hp 53132A / SR620 time interval counters are in episode 1.

The PR link to the episode is:

http://www.pbs.org/genius-by-stephen-hawking/episodes/episode-1/

Attached is a photo. I will post lots of technical info, plots, photos and FAQ 
here next week:

http://leapsecond.com/great2016a/

/tvb
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Re: [time-nuts] GPS position

[Wes]

Nothing to do with time but...

Technically speaking, in surveying a bench mark is a vertical control point.  In 
playing with Geocaching I've located bench marks that were placed in the 1930's 
and never found again (until I did).  There were often a hundred feet or more 
from where the description had them.  (Great fun BTW)


See: https://www.geocaching.com/mark/


On 5/2/2016 9:13 AM, Chris Albertson wrote:

A man with a GPS knows where he is.  A man with two GPS' not not sure.

I've always wanted to walk my self-survey GPS over to a brass USGS
benchmark and see it the GPS matches to benchmark location.  OK, I've done
this with a hand held GPS and gotten readings within about 10 meters.

But before spending a lot of time removing the lat 10cm of error I'd do a
test at the nearest BM that is not in the middle of a street.

What has stopped me from doing this is that a few years ago I had to have
my lot lines surveyed.  They got to better then 1/10 of a foot at each
corner and shot  some brass markers into the concrete.Google can see my
house's roof ridge lines and the concrete so I can work out the exact
location of the roof mount antenna to within maybe 18 inches.  It seems to
agree with the survey as long as everyone uses WGS84.




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Re: [time-nuts] HP Reliability

[Wes (N7WS)]

I was never with HP but I bought (using Hughes Aircraft and US government money) 
megabucks worth of HP Instruments.  The whole facility bought millions more.  
The local Tucson HP sales office had a salesman assigned just to Hughes. They 
showered us with catalogs, app notes, training programs, seminars and I even 
traveled a few times to attend programs elsewhere.  We paid for our own airfare 
and hotel, but breakfasts, lunches, dinners, girly shows, etc were on HP.  In 
discussing travel expense reporting with the rep, unlike Hughes where every 
penny had to be accounted for, he said his reporting consisted of counting the 
money in his wallet when he left and counting it again when he got back.  The 
difference was his expense.


Wes  N7WS


On 2/14/2016 4:05 PM, Jeremy Nichols wrote:
I was with HP 1972-79, when it was still a great company. The vertical 
integration was such that there was a joke about HP plant site landscaping, 
which always seemed to feature ferns. The reply was , "We're making our own 
coal!" We not only had packaging engineers but made our own cabinets. We made 
our own integrated circuits; I made the photomasks for those ICs in the Santa 
Clara Division (02, the old Frequency Division) in building 51-Lower, 
next to the line where the counters were wired. Good times, free coffee.


Jeremy
N6WFO



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[time-nuts] HPZ3801 Failure

[Wes Atchison]

My HPZ3801 has died.  It appears the internal DC to DC converters have died.
The fuses (4) I have found on the boards check good with an ohmmeter.  I
have checked voltage on test points where labeled as a supply.  No voltages
present.  Is there a schematic available somewhere?  Has anyone repaired a
Z3801 with similar problems?

Thanks for any help.

 

73,

Wes

WA5TKU

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