Hi
You don’t have to get into the fancy versions to get a nice quiet supply.
One of the guys at Frequency Electronics (I forget who …) turned me
on to them back in the 1970’s. I have not seen any of them selling for the
sort of prices some other supplies seem to command …. Maybe I just
spend
Hi
In general the way you go from 1 to 10 to 100 seconds is to decimate
( = throw away) the data to get a phase record at the tau you are after.
Any averaging that you do will filter out some noise. Since ADEV is a
measure of noise, getting rid of it is not a real good idea. You can indeed
make
nce is worth
> taking the risk.
>
> Wes
>
> On 5/1/2020 7:29 PM, Bob kb8tq wrote:
>> Hi
>>
>> I would guess that the vast majority of folks on the list and an even
>> larger percentage doing the FMT are buying their GPSDO’s on eBay.
>> Which ones
Hi
A few possible complications:
I suspect you would run into bits and pieces of “stuff” that had
slowly been magnetized inside the C field ( think of things like
component leads). Just how they would impact things depends a
bit on how fast they respond to the change. ( = you have both external
Hi
Indeed, for anything designed as a mobile device, you want the 15V supply
rather than
the 12V. Set it to the low end of the range and you are fine. A lot of mobile
gear is only
happy with > 13V on the input. If it pulls noticeable current, cable drop will
get you on
a 12V supply.
For a
Hi
I would bet you are correct in saying the guys at Microsemi, Symmetricom likely
are the ones
responsible. Microchip has been slowly pushing the uniform “Microchip” brand
labeling onto
the various sub-organizations.
I wonder if Jackson Labs will still be selling them …..
Bob
> On May 4,
now reported as Microchip.
>
> VS
>
>
> A 2020-05-04 18:05, Bob kb8tq escreveu:
>> Hi
>> Marketing and sales, ok. How about manufacturing? Yes, this is getting
>> a bit deep into very subtle distinctions. I suspect I’ll be getting an email
>> at
>> some
Hi
Marketing and sales, ok. How about manufacturing? Yes, this is getting
a bit deep into very subtle distinctions. I suspect I’ll be getting an email at
some point explaining what’s what on the Jackson Labs labeled products.
Bob
> On May 4, 2020, at 12:58 PM, Vasco Soares wrote:
>
> Hi,
>
Hi
A GPSDO would be the “next step” if you want to continue on when GPS
is not present. They are a < $100 sort of thing from a number of sources.
Bob
> On Apr 24, 2020, at 4:38 PM, Andreas Kempe wrote:
>
> On Fri, Apr 24, 2020 at 04:22:46PM -0400, Bob kb8tq wrote:
>>
>&g
Hi
Here’s a few:
20, at 10:06 PM, Frank O'Donnell wrote:
>
> On 4/29/20 6:01 PM, Bob kb8tq wrote:
>> Here’s a few:
>
> Bob, thanks very much for the suggestions.
>
> Five of the seven splitters in your list appear to offer a total of two
> output ports. What I'm looking for is one
would fill my desk already by 50%, so
> no way to leave it there (and therefore I cannot keep it powered).
>
> Tobias
>
>
> On Tue, Apr 14, 2020 at 1:54 PM Bob kb8tq wrote:
>
>> Hi
>>
>>> On Apr 14, 2020, at 2:31 AM, Tobias Pluess wrote:
&
--
> (Mr.) Taka Kamiya
> KB4EMF / ex JF2DKG
>
>
> On Tuesday, April 14, 2020, 7:48:34 AM EDT, Bob kb8tq
> wrote:
>
> Hi
>
> If the phase slips are “well behaved” they can be handled. The problem
> with a dual channel setup is that they are
rary decisions
about how to “patch” them. With a time tagger, most of the problems are
actually dropouts in the data. How you fill those depends on what you
are doing ( you may re-do the run ). Simply putting in the phase data
from the previous point is an alternative.
Bob
>
> Tobias
>
Hi
A picture or two might help in this case …..
Bob
> On May 11, 2020, at 8:58 PM, paul swed wrote:
>
> Bruce not a lot of detail but microsemi seems to sell them at $ 7000
> each min order 3.
> It must be nice. Try reaching out to microsemi. Though these days hard to
> say they will respond.
Hi
A couple other options:
1) Adapt something like a 3540 series part
2) Redo the circuit to use a 10K.
Bob
> On May 12, 2020, at 7:16 AM, tim...@timeok.it wrote:
>
>
> I made a mistake on the product nr.
>
> The correct value is 100k so the pn is 3700S-196-104
>
> As Matthias
Hi
There are a number of free ( = there is no license fee ) pcb layout programs
out there.
One of the many is KiCad. It’s not that hard to use. It is very popular. There
are a lot
of YouTube videos and blogs detailing how to do this or that with it. Laying
out a board
to mount an OCXO on is a
Hi
From the description, it sounds like a frequency translator. Put in a 5 MHz
standard and
get a group of frequencies out. It’s a fairly common solution to putting a
system into an
already equipped platform ( like a ship …).
Bob
> On May 5, 2020, at 6:00 PM, gandalfg8--- via time-nuts
>
Hi
Ok, so what you have is an FEI part that somebody else has messed with.
They mounted it on a box and wired this and that to here and there.
Best guess is that the switch on the top of the unit once did this:
comp = lock the internal standard to an external standard ( = where it is set
now)
Hi
You have a situation where you have only one standard. It has nothing
to compare to. It is very much like asking for the correct time from a single
watch. You can look at the various status outputs. You can look at how it
is set up. Past that, all you know is that it *thinks* it is doing ok.
Hi
A few generic Rb information points:
1) All the telecom Rb’s need an external heatsink. To just mount them on
a PC board, you need a lot of airflow (like fans …).
2) Heat sinking improves the lifespan of these devices. Without a heatsink,
a year or two is doing pretty well. With a heatsink
Hi
> On May 18, 2020, at 1:19 PM, Joseph Gwinn wrote:
>
> On Mon, 18 May 2020 12:00:02 -0400, time-nuts-requ...@lists.febo.com
> wrote:
> Re: time-nuts Digest, Vol 190, Issue 30
>
>> Message: 1
>> Date: Sun, 17 May 2020 12:53:42 -0600
>> From: Eric Scace
>> To: Time Nuts email list
>>
Hi
Without seeing the actual data (and setup) there is a lot of guessing in this.
1) Counter floor ADEV plots *should* all have the same slope. They are a
straight
line until the hit some sort of basic limit. Often this can be the temperature
in the
room impacting the front end delay or
Hi
Well, a full list of all the rules we ran against would run about 10 pages. I
think
that’s getting pretty far off topic for TimeNuts. I also, quite frankly never
bothered
to memorize them all.
A few examples of what one *might* do:
1) “Allow” a violation. Things like courtyard overlaps
Hi
I would toss in:
If you are starting from scratch, pick a program that allows you to easily
enter schematics as well as PCB layouts. Take the time to learn both sides
of the program. That will give you an automated check between the schematic
and the layout….. It also gives you a document to
tended). It
appears that when you go into the extended group, there may be some
minimum order gotchas ….
Bob
> On May 13, 2020, at 9:17 AM, jimlux wrote:
>
> On 5/13/20 5:56 AM, Bob kb8tq wrote:
>> Hi
>> There are a number of free ( = there is no license fee ) pcb layout pro
le EUROCIRCUITS) , which saves you from generating
> Gerbers and drill files.
>
> And Kicad just keeps getting better.
>
> -- mike
>
>
>
> On Thu, May 14, 2020 at 4:30 PM Bob kb8tq wrote:
>
>> Hi
>>
>> I would toss in:
>>
>> If
> On May 7, 2020, at 9:42 AM, jimlux wrote:
>
> On 5/6/20 7:07 PM, Sanjeev Gupta wrote:
>> On Wed, May 6, 2020 at 8:22 PM Bob kb8tq wrote:
>>> If all of that sounds like a lot of work (or not complete enough), buy a
>>> second ( or third
>>> o
Hi
In this era of $5 for 10 boards from China, a lot of folks have laid out various
boards. They aren’t “ready made” but they get past the dead bug stuff.
Bob
> On May 12, 2020, at 1:52 PM, Wes wrote:
>
> Does anyone know of a ready made board that will allow me to mount and at the
> least,
Hi
As the price of these gizmos goes up, the likelihood of them only going into
something *necessary* also goes up. You simply can’t get the purchase
approved otherwise. If you have to do a ship and return, you take that
necessary chunk of the operation offline for (weeks / months?) while that
Hi
> On Mar 19, 2020, at 3:32 PM, Tobias Pluess wrote:
>
> Dear colleagues,
> as you may remember I am still working on my own GPSDO project.
> So far I have populated all the components on the PCBs I made, and I have
> written some very basic software to test everything. Currently, I am
>
Hi
I’m guessing that it is a dewar based OCXO. If so, the *big* question is: Can
the boys at UPS / Fed Ex / DHL / USPS (your pick) get it to you
without cracking the glass bottle? I’ve had reasonable success at shipping them
( = dewar based OCXO’s not HP106’s) in, but not 100%
success.
Hi
Sorry about dumping the text from the previous post !!! Obviously the mailer on
that
machine needs a bit of attention.
So here’s what it *should* have said:
When we are doing typical measurements on our time / frequency standards, much
of it involves measuring noise. In many ways it is
w they would compare directly. On the TimePod data run I could fairly
easily map the ripples to the changes in room temperature.
>
> On Tue, 24 Mar 2020 08:03:31 -0400
> Bob kb8tq wrote:
>
>> One of the nice things about devices that work like a DMTD is that measuring
>
Hi
That does not help you optimize the noise in a GPSDO. It’s targeted
at a completely different aspect of the control process.
Bob
> On Mar 7, 2020, at 6:04 PM, Hal Murray wrote:
>
>
> kb...@n1k.org said:
>> As far as I know there is no “closed form” solution to tuning a GPSDO. It is
>>
Hi
Backing up a bit …. the objective is not to minimize overshoot or
keep the loop from oscillating. The issue here is optimizing the noise
output of the combination of GPS + OCXO when combined via
the control loop. It’s a very different objective ….
Bob
> On Mar 7, 2020, at 8:01 PM, Bill
Hi
In this case the “phase” is phase correction of the output rather than PLL ….
Bob
> On Mar 9, 2020, at 10:58 AM, Matthias Welwarsky
> wrote:
>
> On Montag, 9. März 2020 15:04:40 CET Bob kb8tq wrote:
>> Hi
>>
>> If you go that way, just run a pure FLL for th
Hi
Since the unit is still in warranty, I’m a bit hesitant to crack it open and
start
poking around :).
While it’s not 100% obvious, the ADC clock comes out the back and then
returns to the unit via a SMA jumper. At least in theory you *could* supply
your own clock to the unit. How well that
Hi
> On Mar 24, 2020, at 7:31 PM, jimlux wrote:
>
> On 3/24/20 2:17 PM, John Miles wrote:
It would be interesting to know what ADC was used and if there's an
SDR-board out there that uses the same ADC.
>>>
>>> Uh.. I remember John telling me what ADC it was, but I forgot, sorry.
>>
Hi
With any GPSDO (not just the TBolt) you can do some basic checks:
(They are in no particular order)
1) Are there > 6 sats in view at all times, if not, move the antenna
2) Is the unit locked to at least 4 sats at all times, if not, move the antenna.
3) Has the unit completed its survey
OP, is he a phase-nut or a
> frequency-nut? :-)
>
> Tim N3QE
>
> On Wed, May 6, 2020 at 8:22 AM Bob kb8tq wrote:
>
>> Hi
>>
>> With any GPSDO (not just the TBolt) you can do some basic checks:
>> (They are in no particular order)
>>
>> 1) Are ther
Hi
> On May 8, 2020, at 5:12 PM, Hal Murray wrote:
>
>
> Is there any published data on what happens to the quality of time if the
> survey is off by xxx meters?
Speed of light plus distance off “correct” plus constellation geometry are what
are usually tossed into examples. Turning that
Hi
> On May 2, 2020, at 8:10 PM, Perry Sandeen via time-nuts
> wrote:
>
> Learned Gentlemen,
> I personally dislike equipment that uses *wall warts* due to quality concerns
> One inexpensive way I've powered my Lucent equipment is using used laptop
> power supplies. They're easily found at
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> or, via email, send a message with subject or body 'help' to
> time-nuts-requ...@lists.febo.com
>
> You can reach the person managing the list at
> time-nuts-ow...@lists.febo.com
>
> When replying, pl
le of
> 15V 7A ones that will adjust down to 14.1 and I’d like to get them down to
> the 12-13.8 range.
>
> Steve
> WB0DBS
>
>
>
>> On May 3, 2020, at 8:43 AM, Bob kb8tq wrote:
>>
>> Hi
>>
>>
>>> On May 2, 2020, at 8:10
t one of the 12V ones and open it up and do a comparison. I
> thought maybe someone had been down that path before.
>
> Steve
> WB0DBS
>
>
>
>> On May 3, 2020, at 9:15 AM, Bob kb8tq wrote:
>>
>> Hi
>>
>> If you want to do it and get full ou
Hi
The gotcha with all this is the temperature coefficient. If they all have
roughly the same +100 ppm / C tempco (which they might), then the typical
lab temperature swing of 2 to 4 C will have them out in the 200 to 400 ppm
range (and more or less tracking each other ….).
1 LSB on a 16 bit
Hi
A number of us have Trimble TBolt’s that have been running for over 10 years.
The early HP’s (Z3801 … ) seem to have a weakness in the power supply section.
So far mine have come back to life after simple repairs. That puts the into the
20+
year range. The “Nortel” GPSDO’s seem to just keep
Hi
OCXO aging is not “linear” in the fashion you are trying to interpret it. Put
another way,
daily aging does not equal yearly aging / 365. Hourly aging does not equal
daily aging / 24.
The drivers are not that simple or that well behaved. If you find a spec that
calls out a lot
of details,
s often
>> conducted to keep it hot inside. How do I reconciliate these opposing
>> conditions in actual use?
>>
>> -----------
>> (Mr.) Taka Kamiya
>> KB4EMF / ex JF2DKG
>>
>>
>>On Tuesday, September 1, 2020, 2:08:04 PM EDT, Bob kb8tq &
> (Mr.) Taka Kamiya
> KB4EMF / ex JF2DKG
>
>
> On Tuesday, September 1, 2020, 2:08:04 PM EDT, Bob kb8tq
> wrote:
>
> Hi
>
> In this case there may not be much that can be done. In the more general case
> ( = a unit with a surface that mates to a heatsink)
Hi
> On Sep 1, 2020, at 4:09 PM, Hal Murray wrote:
>
>
> kb...@n1k.org said:
>> I believe that they simply don’t have a body of long term data “in house” to
>> study.
>
> Interesting topic.
>
> How many units do you have to test to get useful data?
Likely a couple hundred spaced out over a
Hi
The one thing you don’t want to do is play with insulation. There are two ovens
in a
normal Rb. Their temperatures are close to each other. It will not work if the
temperatures
are equal ( = there are reasons for the delta).
Since the two ovens are right up against each other, there is
Hi
> On Sep 2, 2020, at 1:24 AM, Manfred Bartz wrote:
>
> Hi all,
>
> I bought 2 x 10811 OCXOs for a 10MHz GPSDO project I am working on.
> The OCXOs came with an interface board HP 05328-20027, see attached
> pictures.
>
> Questions:
> 1. Is it worth keeping the interface board?
They make
Hi
That interface board *may* use a biased transistor to convert sine to square.
It’s been a while since I looked at it …..
Bob
> On Sep 2, 2020, at 10:00 AM, Mike Feher wrote:
>
> I remember the days when we had to build our own discrete Schmitt trigger to
> do this. 73 - Mike
>
> Mike B.
Hi
Unless the pad is damaged, it makes a fine “gap filler” to attach the device
to a heatsink. You don’t get thermal compound all over everything when using
the pads ….
Given the (large) surface area and the amount of heat involved, the relative
performance of silver loaded (gray) thermal
Hi
So, *assuming* there is no other ADC on the board ….
DC performance of the STM8 ADC’s is somewhere in the 8 to 9 bit range as far
as ENOB with significant averaging. For the sake of simplicity, let’s say they
*do*
make it to 10 bits.
But … do we get the 10 bits?
The range on the meter is
Hi
You actually have at least three components to your setup:
1) You have the *source* impedance of your signal
2) You have the impedance / length / loss / stability of the cable connecting
the
source to the load
3) You have the load impedance.
In an ideal world, you would have cable that
Hi
A couple things to check:
1) Is your power supply doing odd things? It’s the first thing I’d suspect in
this case.
2) Does the OCXO “behave” if you turn off the GPS ( = disconnect the antenna )
and watch
it with a counter?
3) While the antenna is disconnected from the TBolt, hook it to
Hi
Well …. 4.19304 = 2^22
I’d bet they used a bunch of divide by 2 ( or 2^N ) parts. :)
At some point they went from electronic division to driving gears. Is that what
he’s looking for?
or is he after the brand / model of divider chip? It’s quite possible that they
used a custom part,
even
.microchip.com/downloads/en/DeviceDoc/22003e.pdf
>
>> Sent: Monday, September 07, 2020 at 1:15 PM
>> From: "Bob kb8tq"
>> To: "Discussion of precise time and frequency measurement"
>>
>> Subject: Re: [time-nuts] 5 Digit Panel meters
>>
Hi
Depending on your definition of “accuracy”, and the actual device, the answer
is likely
in the 1 ppb to 10 ppt range based on a 10 second measurement.
What’s going on?
First up you have the basic accuracy of GPS. Over many days of averaging (with
a fairly
fancy averaging device) that can
Hi
First off, 0.001 seconds per year is ~ 3x10^-11. If you are talking about
the 2G tip effect on a typical AT cut crystal that’s up around 2 ppb.
Next up, low frequency / small package crystals are (inevitably) relatively
low Q devices. Low Q degrades ADEV performance / increases noise. If
IB.
GPIB is great for setting up multiple runs on a counter or for doing odd things.
One of those is running 100 second long data with a 5335. There are cheap
USB dongles out there to do the GPIB if you decide to go that way.
Bob
>
> On Tue, Sep 8, 2020, 1:12 PM Bob kb8tq wrote:
>
>
> On Sat, Sep 12, 2020 at 2:17 PM Bob kb8tq wrote:
>
>> Hi
>>
>> One *might* consider reaching out to those winding down Spectrum and see
>> if they might be willing to “donate” the source code to IEEE ( or some
>> similar
>> institution ). That’s what was d
Hi
One *might* consider reaching out to those winding down Spectrum and see
if they might be willing to “donate” the source code to IEEE ( or some similar
institution ). That’s what was done with Stable-32.
Bob
> On Sep 12, 2020, at 1:04 AM, Lloyd Blythen wrote:
>
> Thanks Bob.
>
> About a
ampaign=sig-email_content=webmail>
> Virus-free.
> www.avast.com
> <https://www.avast.com/sig-email?utm_medium=email_source=link_campaign=sig-email_content=webmail>
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
>
> On Fri, Sep 11, 2020 at 1:15 AM Bob kb8tq wrote:
>
&g
Hi
The unit your link points to *is* the “classic” TBolt that showed up in volume
a bit
over a decade ago. That one is packaged with a (noisy) switching power supply.
There is no easy way to tell what era it is from. Indeed if it is from the
1990’s the
OCXO will not be quite as good as
Hi
As far as anybody knows (which *is* a big qualifier indeed ….), the TBolt
family only
does it’s “temperature compensation” stuff when it’s in holdover. While it’s
locked, there
*appears* to be no compensation being done. If it’s doing anything while
locked, it’s
learning what the TC is, so
oned part 48050-61 but as you say, that seems to be common to all of
> them.
>
>
> On Sat, Sep 12, 2020 at 10:14 PM Bob kb8tq wrote:
>
>> Hi
>>
>> The unit your link points to *is* the “classic” TBolt that showed up in
>> volume a bit
>> ov
Hi
> On Sep 14, 2020, at 3:59 AM, Matthias Welwarsky
> wrote:
>
> On Sonntag, 13. September 2020 15:05:36 CEST Bob kb8tq wrote:
>> Hi
>>
>> The point is that there is no need to compensate the part while it is
>> locked.
>
> It depends. For sho
*and* learn at the same time generates even
more issues to deal with. The temperature effect is not a simple linear / first
order sort of thing ….
Bob
> On Sep 13, 2020, at 1:41 AM, Matthias Welwarsky
> wrote:
>
> On Samstag, 12. September 2020 23:53:39 CEST Bob kb8tq wrote:
>>
Hi
As mentioned in PHK’s post, FPGA’s are quite noisy. They also tend to have
crosstalk issues if you put a whole bunch of nearly identical inputs into them.
So backing off a bit:
What are you trying to measure? Are you after parts in 10^-13 or parts in
10^-8?
That will make a *big*
Hi
Best guess is that the oven circuit has “issues”. If that’s the case, it will
go on pretty much forever and ever. Without a plot, it’s sort of hard to
guess ….
Bob
> On Sep 4, 2020, at 2:50 AM, Matthias Welwarsky wrote:
>
> Hi,
>
> I mentioned in a previous email that I seem to have
Hi
> On Sep 4, 2020, at 3:37 PM, Matthias Welwarsky wrote:
>
> Dan,
>
> I've attached the last 25000 seconds of data. The drift was about 15 DAC
> units
> during this time. It's a 16 bit DAC, the pulling range is about 10Hz, so LSB
> is worth 1.5e-4 Hz. 15 DAC units are 2.3e-3 Hz over
Hi
….. ummm …. e …..
> On Sep 4, 2020, at 2:04 PM, rfnuts wrote:
>
> Hi,
>
> given it is a 10MHz OCXO, your drift is just 4E-11/hour or 9.6E-10/day, which
> isn't terribly bad, is it?
>
> A good modern OCXO is specified at +/- 0.2ppb/day (2E-10) after 30 days of
> continuous operation.
Hi
In this case there may not be much that can be done. In the more general case
( = a unit with a surface that mates to a heatsink) , it’s well worth doing
something.
I have an unfortunate lot of empirical evidence (on FRK’s and LPRO’s ) showing
that
a “no heatsink” setup is one with a
Hi
Since you don’t know all the parameters of the design of the 53310, it’s going
to be
tough to define “best” in terms of an OCXO. None of the parts on your list are
better
than a 10811 in all respects.
Best to simply get a couple of 10811’s for $40 or so and spend some time
sorting them
Hi
Measurement accuracy as stated in the listing is 0.3% or 3,000 ppm. Some
listings call it out
as 0.3% +/- 2 LSD. Since they removed the markings from some of the chips,
figuring out exactly
what’s in there could be a bit exciting.
Full scale is 33V so the full range display would be
rm I was way off). I do hope to move up to a
>>>> basic
>>>> home lab running off CSAC and Rb standards in the next few years once
>>>> I've
>>>> seen all there is to see in wristwatches, but it looks like I have a
>>>> lot to
>>>>
Hi
Ok so you have a step change in temperature of say 2C over 5 seconds. What
(might) happen:
(Yes this is all a bit contrived, but it *is* the sort of thing that’s going on
in the TBolt). The units
shown are “Bob Units” :). They have no particular relation to LSB’s or to
PPT’s.
At 18
playing with
compensation. It met the
spec so why spend the money …..
Bob
> On Sep 13, 2020, at 10:28 AM, Adrian Godwin wrote:
>
> But doesn't the compensation help generate a feed-forward term, a way to
> make the integrator better managed ?
>
> On Sun, Sep 13, 2020 at 2:31 P
Hi
Maybe a good idea to “back up” a bit here:
The most commonly plotted data for the performance of a GPSDO is ADEV.
Very simply put, to do ADEV you take a series of readings at a specific time
spacing ( called tau ). The delta frequency from one reading to the next is then
computed. You take
Hi
If it was a custom chip, then the motor driver “stuff” would be integrated into
the
IC. That was indeed the case back in the 1970’s when I was designing this sort
of thing. Those chips were pretty hard to dig up, even back then. Unless you
wanted
to buy >10K pcs a month, they really didn’t
ng in. The same for the synthesiser. I could
> swear someone on time-nuts already has. The phase detection circuit is
> audio and it would take some experimentation. I think Corby supplied an
> alternative approach on the A7 opamp so a lot of good work.
> But the charcoal problem ment
parts. $$$ Whats a dead 5065 go for chuckle?
> Regards
> Paul
> WB8TSL
>
> On Tue, Oct 6, 2020 at 6:27 PM Bob kb8tq wrote:
>
>> Hi
>>
>> Replacing the synthesizer with something more modern is certainly
>> possible. I have
>> a project (slowly mov
Hi
A lot depends on your antenna setup. You can also swamp out the incoming
WWVB signal…….
Bob
> On Oct 8, 2020, at 2:07 PM,
> wrote:
>
> I have read several different articles where the WWVB phase shift is
> eliminated by doubling the signal to 120 kHz. Several members of the
> list have
Hi
It would be far easier to just use a (stock) 48 bit chip than to try to
get something like that up and running ….. Keeping all the transitions
“just right” would be tough. If you don’t do that, you have a major added
source of spurs.
Bob
> On Oct 8, 2020, at 10:14 AM, Lester Veenstra via
S
> 89 Arnold Blvd.
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> -Original Message-
> From: time-nuts On Behalf Of Bob kb8tq
> Sent: Wednesday, October 7, 2020 11:11 AM
> To: Discussion of precise time and frequency measurement
>
> Subject: Re: [time-nuts] Aging 5065A
> On Oct 8, 2020, at 4:50 PM, rcb...@atcelectronics.com wrote:
>
> Bob,
>
> I am using a ferrite rod antenna for the receiver. No outside antenna.
>
> Ray
>
> Original Message
> Subject: Re: [time-nuts] WWVB Dephaser Question
> From: Bob kb8tq
&g
48-245-9115
>
> -Original Message-
> From: time-nuts On Behalf Of Bob kb8tq
> Sent: Wednesday, October 7, 2020 7:34 PM
> To: Discussion of precise time and frequency measurement
>
> Cc: hmur...@megapathdsl.net
> Subject: Re: [time-nuts] Aging 5065A ?
>
Hi
There are a *lot* of ways 60 Hz (and other power related) signals can get into
an
RF chain. Pretty much anything that modulates the ground can modulate the (net)
supply to various stages. Modulate the supply and you get AM and PM noise…..
Taking care of ground loops is a significant part of
Hi
On an oscillator that is 50 years old, there likely has been some aging of the
crystal
and other components. As you tune the crystal back onto frequency, you can
easily
impact the EFC sensitivity. On *any* older device, “measure” is very much the
right
way to do it.
Bob
> On Oct 2, 2020,
Hi
You *are* talking about a 60 KHz sine wave when playing with WWVB. The
typical receiver had a fairly narrow passband. This generally was accomplished
with both high Q tuned circuits and a crystal filter. The typical antenna loop
antenna
also had a fairly high Q tune on it. Even if the signal
Hi
This is another of the many devices out there that pre-date the
“modern” 180 degree phase modulation approach on WWVB. Getting
one of these to run properly with the new modulation approach would take
some major mods …..
Bob
> On Oct 4, 2020, at 10:23 AM, Magnus Danielson wrote:
>
> Hi,
>
> .ılılı..ılılı.
> notfaded1
>
> On Sun, Oct 4, 2020, 2:54 PM paul swed wrote:
>
>> Agree with Bobs comment. The 180 degree phase flip killed all of the gear
>> unless significant mods are done or the d-psk-r is used. Great old boxes
>> though.
>> Regards
>
k is that there has never been sort of
>> a open development platform. Anyone who has played with the ES100 will run
>> into some issues that are annoying for a time nut to tinker with.
>> Regards
>> Paul
>>
>> On Sun, Oct 11, 2020 at 10:39 AM Bob kb8tq wrote:
&
Hi
I’m not quite sure I understand the "2 DIL 80 MHz-oscillators” part.
If you have the power divider, isn’t one oscillator going to do the job?
=
Isolation between the two channels can turn into a bit of a nightmare …..
Bob
> On Oct 17, 2020, at 8:59 AM, Gerhard Hoffmann
> wrote:
>
with increasing ambient, which should
> make the DAC volts trend increase at the same time, but it is trending more
> negative - I wonder if this is not an issue of crystal aging...
>
> The attached screenshot is around 48 hours long, but a 2 week long capture
> at 10second rate has
Hi
The TimePod is a measurement device designed by John Miles. It will accept
an input up to just above 30 MHz. If you want to look at something above
that frequency, you need a downconverter. The TimePod will handle inputs
up into the 15 to 20 dbm range. If one wished to preserve this
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