Re: [time-nuts] Bodnar "Precision Frequency Reference (GPS Clock)" AND LeoNTP Networked Time NTP Server Questions

[Mark Goldberg]

Leo and I are already discussing it off list and he is trying to duplicate
my measurements.

Regards,

Mark

On Fri, May 18, 2018, 10:08 AM Denny Page  wrote:

> Have you considered asking Leo? In my experience, he is very helpful.
>
> Denny
>
>
> > On May 17, 2018, at 19:19, Clay Autery  wrote:
> >
> > Anyone who is using one (or both) of these, and/or folks who have a
> logical opinion:
> >
> > *"GPSDO"* - Once configured, unit can run on an external DC source
> (5-15VDC).  I am NOT using it to power the mast mounted timing antenna.  I
> don't anticipate leaving unit connected to a computer when not configuring
> UNLESS I can figure out how to grab data from the unit via the USB port for
> reporting/analysis.
> >
> > Questions:
> > 1)  What are the specs of the DC plug on the back?  If I use an external
> supply, I want to eliminate the addition of yet another SMPS/wall wart to
> the clutter.
> >
> > 2) IF you were choosing a voltage to run JUST this unit on
> big/short/twisted/ferited leads, what voltage would you choose (regulating
> down from 13.8VDC or so).  Anything above the required minimum will be
> converted to heat in either the unit or at the regulator.  Considering this
> uses a TXCO (I think) and not an OXCO or DOXCO, is running it hotter to try
> and achieve a more consistent internal temp worth the tradeoff in
> potentially shortened life of the unit.  (Bottom Line: What voltage will
> make it run most accurately/consistently?)
> >
> > *LeoNTP Networked Time NTP Server* -  Can be powered via USB or PoE
> according to website.  Detailed specs are seriously lacking.  Trying to
> wade through how to power it.  USB is obviously 5vdc or a bit less  But
> the PoE could be much higher with an internal regulator(s)
> >
> > -  I haven't bought my new switch yet, so I can buy one with PoE
> capability or otherwise inject PoE on the Ethernet cable from the NTP
> Server to the Gbit switch.
> > -  All Ethernet cables in my network are CAT-7 STP (shielded twisted
> pair) or better.  (Yeah, yeah, I know, wired Ethernet can be noisy, but you
> do the best you can.  IF wired Ethernet becomes an issue, I can back up to
> the wireless network.)
> > -  Not sure how much I plan to have the unit connected via USB. Beyond
> curiosity data gathering for a while, I'm thinking at some point I want it
> to be disco'd and forgotten.  One less potential USB cable radiating or
> needing ferrites.
> >
> > There's more...  but this is a good start.  Just want to try and get
> parts on the way.  Have to build a separate outboard regulator for the
> timing GPS antenna, too.
> >
> > Thanks!
> >
> > --
> > *Clay Autery
> > (318) 518-1389
> > MONTAC Enterprises*
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Bodnar "Precision Frequency Reference (GPS Clock)" AND LeoNTP Networked Time NTP Server Questions

[Mark Goldberg]

On Thu, May 17, 2018 at 7:19 PM, Clay Autery  wrote:

> Anyone who is using one (or both) of these, and/or folks who have a
> logical opinion:
> -  Not sure how much I plan to have the unit connected via USB. Beyond
> curiosity data gathering for a while, I'm thinking at some point I want it
> to be disco'd and forgotten.  One less potential USB cable radiating or
> needing ferrites.
>

I have the Bodnar Mini which only has a USB connection. You can connect it
to a USB power only source. I have found a large variation (20 dB) in close
in phase noise, depending on how clean the power source is. I am using a
power only wall wart with an added series ferrite core / shunt cap to get
acceptable results ( -103 dBc/Hz at 10 Hz offset). I don't know if there is
more internal filtering on the separate power input of the 2 output
version. So far peak ADEV at Tau = 20s is about 2e-10. It would be nice to
improve that.

You can also get widely varying spurs, phase noise and ADEV depending on
the register values chosen to provide a specific output frequency. Many
different sets of register values may be used to provide the same output
frequency. I have not determined a pattern. I just calculated different
values and tried them out.

Regards,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] TruePosition GPSDO Holdover Issues

[Mark Goldberg]

What antenna are you using and where is it located?  I have the
TruePosition with a Motorola PCTEL 8508851k66 antenna on a windowsill with
a ground plane under the antenna and it generally sees 4-7 sats. I have
seen some holdovers but it has been better after running for a while and
doing a survey. The TruePosition seems to switch between modes 0 and 1 as
new sats come into view. The 10 MHz out does not change that I can see when
this happens.

Regards,

Mark
W7MLG


On Fri, May 11, 2018 at 10:56 AM, gandalfg8--- via time-nuts <
time-nuts@febo.com> wrote:

> I've had one of the cheap TruePosition GPSDOs running here for the past
> week, this is the earlier version with the Bliley oscillator, and as Mark
> reported have been seeing what I consider to be excessive holdover reports
> from Lady Heather.
>
> At 55 degrees north the number of Sats visible can be a bit variable, and
> with this running on an indoor antenna probably even more so, but I've run
> plenty of other GPSDOs here in similar fashion and have not seen this
> before.
>
> I've not been running Lady H in logging mode, just running in the
> background when this PC is on so all a bit hit and miss, but I have been
> seeing holdover reports every day and with the time building up as the day
> goes by. The time never exceeds 5 or 6 minutes though so if it was just
> being used as a reference without monitoring the status this could easily
> go unnoticed.
>
> The LMU300 Location Measurement Unit that this comes from will need to
> track four Sats for positioning purposes, and the manual for that does
> state that the LMU300 will indicate a holdover alarm when "The LMU cannot
> lock on to the minimum number (4) of GPS satellites and the LMU GPS
> receiver board has been in holdover for over 15 minutes", and I had started
> to wonder if the firmware in the GPSDO might also be treating less than
> four Sats tracked as a holdover situation.
>
> Earlier this afternoon I happened to catch it with between three or four
> Sats being tracked and it did seem to be dropping in and out of holdover as
> the number varied, once the number of tracked Sats increased again and
> stayed there, it's been six for some time now, it settled down again and
> hasn't returned to holdover since.
>
> Hardly the stuff of scientific observation I know, and I need to start
> logging what's happening, but it does seem more likely now that these units
> could be reporting a holdover event when the number of tracked Sats drops
> below four.
>
> Nigel, GM8PZR
>
>
>
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] TruePosition GPSDO Holdover Issues

[Mark Goldberg]

It definitely works better on a windowsill than under the roof. It also did
not work at all with a patch antenna.

I can compare it to another GPSDO used as a reference and I see ADEV in the
range of 2.5E-10 for low Tau 10-1000s, heading down for larger Tau. I see
phase noise of -102 dBc/Hz at 10 Hz offset, getting better from there.

Regards,

Mark
W7MLG

On Fri, May 11, 2018 at 12:33 PM, <gandal...@aol.com> wrote:

> Hi Mark,
>
> The antenna is a Micropulse 1373FW/D, described on the label as an L/W
> Survey GPS Antenna, whatever that might mean, Land and Water perhaps?:-)
> I did try a small Motorola magnetic patch, I regularly use these with
> Thunderbolts etc with no problems, but as Mark Sims predicted the
> Trueposition reported an antenna error with that, although I'm not sure why.
> This antenna is on top of the metal case of some test gear, just below
> ceiling height in a single story building and at the moment the unit is
> tracking six sats.
> As commented earlier, we're at 55 degrees north so there's a big empty
> space between northwest and northeast and the number of sats is a bit
> variable.
> What I'm seeing though is about par for the course with this setup, this
> one is showing six sats at the moment and seven or eight, the max for this
> GPSDO, isn't unusual and this is generally much the same as I'd expect
> anyway, but this is the only one I've seen dropping in and out of holdover.
> I did run a survey when I first set it up and it's fine re position.
> I haven't got a counter on it at the moment but was monitoring it with a
> CNT91 earlier in the week and I couldn't see any change in the output
> either, but having said that if it was handling the holdover properly then
> there shouldn't be any obvious change in the short time scales we're
> talking about anyway.
>
> I'm happy with the setup, dropping down to just a few sats isn't unusual
> here, but again this is the only one I've seen behaving like this so I'm
> still inclined to think it's doing what it's supposed to.
> I'll try to set up some continuous logging over the weekend and see if I
> can get any more definite correlation between number of sats tracked and
> indicating holdover.
>
> Regards,
>
> Nigel, GM8PZR
>
>
>
> -Original Message-
> From: Mark Goldberg <marklgoldb...@gmail.com>
> To: gandalfg8 <gandal...@aol.com>; Discussion of precise time and
> frequency measurement <time-nuts@febo.com>
> Sent: Fri, 11 May 2018 19:59
> Subject: Re: [time-nuts] TruePosition GPSDO Holdover Issues
>
> What antenna are you using and where is it located?  I have the
> TruePosition with a Motorola PCTEL 8508851k66 antenna on a windowsill with
> a ground plane under the antenna and it generally sees 4-7 sats. I have
> seen some holdovers but it has been better after running for a while and
> doing a survey. The TruePosition seems to switch between modes 0 and 1 as
> new sats come into view. The 10 MHz out does not change that I can see when
> this happens.
>
> Regards,
>
> Mark
> W7MLG
>
>
> On Fri, May 11, 2018 at 10:56 AM, gandalfg8--- via time-nuts <
> time-nuts@febo.com> wrote:
>
> I've had one of the cheap TruePosition GPSDOs running here for the past
> week, this is the earlier version with the Bliley oscillator, and as Mark
> reported have been seeing what I consider to be excessive holdover reports
> from Lady Heather.
>
> At 55 degrees north the number of Sats visible can be a bit variable, and
> with this running on an indoor antenna probably even more so, but I've run
> plenty of other GPSDOs here in similar fashion and have not seen this
> before.
>
> I've not been running Lady H in logging mode, just running in the
> background when this PC is on so all a bit hit and miss, but I have been
> seeing holdover reports every day and with the time building up as the day
> goes by. The time never exceeds 5 or 6 minutes though so if it was just
> being used as a reference without monitoring the status this could easily
> go unnoticed.
>
> The LMU300 Location Measurement Unit that this comes from will need to
> track four Sats for positioning purposes, and the manual for that does
> state that the LMU300 will indicate a holdover alarm when "The LMU cannot
> lock on to the minimum number (4) of GPS satellites and the LMU GPS
> receiver board has been in holdover for over 15 minutes", and I had started
> to wonder if the firmware in the GPSDO might also be treating less than
> four Sats tracked as a holdover situation.
>
> Earlier this afternoon I happened to catch it with between three or four
> Sats being tracked and it did seem to be dropping in and out of holdover as
> the number varied, once the number of tracked Sat

Re: [time-nuts] suggestions on getting 24 Mhz ?

[Mark Goldberg]

On Wed, Apr 11, 2018 at 11:15 AM, Bob kb8tq  wrote:

> Hi
>
> > On Apr 11, 2018, at 12:11 PM, Graham / KE9H 
> wrote:
> >
> > Phase noise is (usually) more important than absolute frequency accuracy.
>
> It’s probably well worth looking into exactly what you are after in terms
> of phase noise,
> spurs, and stability *before* deciding on a solution. In some cases things
> like DDS spurs
> are a non-issue. In other cases phase noise at certain offsets is a really
> big deal, but at
> other offsets … it’s a non-issue.
>
>
I am using the single output Bodnar GPSDO driving a frequency locked Wenzel
low phase noise oscillator and using that for my SDR ADC clock. I am using
it to take phase noise measurements and it certainly is as good as the
references I have available, and matches pretty well with measurements on a
$90k phase noise meter.

The Wenzel eliminates far out spurs from the GPSDO. Note that different
register values may result in the same frequency output of the GPSDO, but
spurs can be very different. For some frequencies and with the right
register values, I expect the GPSDO alone may be good enough for an SDR
clock, but I have not tried.

This is the best I can measure with this setup. I think the ADC noise
limits the far out phase noise.

Offset   Phase Noise
(Hz)   (dBc/Hz)
10 -96.9
20   -103.0
50   -106.9
100 -109.7
200 -117.7
500 -128.4
1,000  -136.4
2,000  -140.1
5,000  -143.1
10,000-144.9
20,000-145.6
50,000-145.7
100,000  -146.2
1,000,000   -146.6

Regards,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Environmental sensor recommendations

[Mark Goldberg]

I will comment on a couple postings:

On Wed, Apr 4, 2018 at 8:00 PM, Tisha Hayes  wrote:
>
> I would suggest that if you are looking at taking temperature sensor data
> and attempting to control some type of heating/cooling device that you
> implement a PID loop for stability.

I have implemented a PID controller with PWM output for a Peltier Cooler
for what is basically an oven to test TCXO boards. Performance is pretty
good, holding the temperature to within tenths of a degree.
I tend to connect sensors or sensor boards to an Arduino and output data to
and take commands from the serial port. The Arduino does the "real time"
stuff and the fancier stuff is implemented on a PC.


On Thu, Apr 5, 2018 at 6:20 AM, Bob kb8tq  wrote:
>Hi
>
>If you want something that is pre-calibrated, then the IC based parts are
the way to go.

I have used thermocouples with MAX31855 thermocouple interface boards and
also have used DS18B20s, which are quite interesting "IC" parts. You can
connect several in parallel, and they use the "One Wire" protocol, easy to
implement, saving wires. The problem with them is there are lots of
counterfeits out there. I bought them from a random supplier and they did
not work correctly. I contacted the manufacturer and they confirmed they
never made any with the date code that was printed on them. I bought some
from Digikey and they looked different and worked fine. Luckily I was able
to return the bad ones.

Regards,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] LT1016 as a pulse shaper...

[Mark Goldberg]

Search for ultra fast comparator yields TL3016 and AD8611, claims to be
faster pin compatible replacements.  I have found low parasitic capacitance
on the outputs of these types of comparators is important, and I have used
balanced hysteresis (use positive feedback from both + and - outputs). I
haven't needed jitter lower than 10 ns or so, with awful inputs, so have
not optimized for lower jitter.

Search google for "ultra fast comparator" and several turn up that are in
the low ns or hundreds of ps range for prop delay. ADCMP566, TL3116,
LMH7322, LTC6752, MAX9691 turn up among others. I haven't investigated or
used any of them.

Regards,

Mark Goldberg




On Sat, Mar 3, 2018 at 10:08 AM, Ulf Kylenfall via time-nuts <
time-nuts@febo.com> wrote:

>
> Gentlemen,
> I have so far been using LT1016 as a pulse shaper and also whenever I
> needed toconvert a sine wave into TTL Logic levels. Some hysteresis and all
> the decouplingand layout precautions as recommended by LT.
> Are there any similar or better alternatives out there that could be
> usedthat would provide lower jitter and that are less expenceive?
> Ulf Kylenfall
> SM6GXV
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP 5065A super

[Mark Goldberg]

My reading of IPC J-STD-001F Paragraph 4.5 says that the gold embrittlement
issue does not apply to ENIG or ENEPIG. Paragraph 4.5.1 does say other gold
shall be removed so there won't be solder embrittlement.

Is that still correct?

The issue with ENIG and RF is interesting. I have not heard that before but
I can find lots of info on the subject. I do not remember seeing ENIG on
microstrip boards.

Regards,

Mark


On Thu, Feb 22, 2018 at 2:33 PM, Tom McDermott  wrote:

> In general it's bad practice to gold plate SMT solder pads.  The reason is
> that proper SMT soldering utilizes a very small amount of solder and the
> gold plating
> will partially dissolve into the molten solder. Because of the small amount
> of
> solder, the percentage of gold will be high enough to embrittle the solder
> joint,
> and it will have a high probability of failure.
>
> Hand soldering can apply a large enough amount of solder that the
> percentage
> of gold in the joint is relatively small and the problem is avoided.
>
> -- Tom, N5EG
>
>
>
>
> On Thu, Feb 22, 2018 at 12:29 PM, Leo Bodnar  wrote:
>
> > Here is ENIG fact that is not widely known at the moment but which some
> > might find useful.
> >
> > I could not understand why I get better TDR and insertion loss results
> > from solder-mask covered microstrip transmission lines than from
> otherwise
> > identical microstrips on the same substrate with soldermask removed and,
> > therefore, covered with ENIG.
> >
> > Gold can't be bad, right? As it turns out, even gold coin has two sides
> to
> > it.
> >
> > I have found that Shlepnev and McMorrow conducted extensive research and
> > published data, some of which is presented here
> http://www.simberian.com/
> > Presentations/NickelCharacterizationPresentation_emc2011.pdf
> >
> > In essence, it's not the "G" that is the problem - it is the "N".
> > Immersion Gold layer is not thick enough to contain whole of the skin
> > effect layer (even towards 100GHz) and as signal frequency increases most
> > of the signal ends up travelling through Nickel.
> > As Shlepnev commented "Nickel is the most mysterious metal in
> > electronics."  It has significant effect on insertion loss and risetime
> > degradation.  "Significant effect" is posh for "bad."
> >
> > Some mass PCB manufacturers have been known to apply ENIG before
> > soldermasking.  This causes even more high speed/frequency problems
> because
> > all of the copper on the outside layers will have Nickel over it -
> exposed
> > or not.
> >
> > Probably not a problem for majority of ENIG users but could cause a
> > headache or two for unsuspecting.
> >
> > Leo
> >
> > > Date: Thu, 22 Feb 2018 19:02:25 +
> > > From: Mark Sims 
> > >
> > > Yes, have the board done with ENIG gold.  It typically adds around $15
> > per run of boards.  I do all my boards with ENIG gold... if for no other
> > reason than the gold color makes it very easy to determine when your
> solder
> > paste properly covers the pads.
> > >
> > > And, as Charles mentioned,  the quality and thickness of the gold can
> > vary depending upon the board house.  I have used gojgo.com for a lot of
> > boards.  They do very good, quick work,  are well priced, and they seem
> to
> > have the best gold finish.
> > >
> > > Hard gold finish is VERY expensive these days.  I've been quoted $250+
> > for setup charges and per-board costs of over $25.
> >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> > mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] The "NAKED" 5065A optical unit

[Mark Goldberg]

On Tue, Feb 20, 2018 at 2:30 AM, Poul-Henning Kamp 
wrote:

> If that is the case, I think it will make sense to give the lamp
> its own adjustable voltage regulator (LM317), so the power can be
> reduced to what is optimal/necessary without having to take the
> lamp apart and change a resistor.
>

I don't know anything about these devices, but for TCXOs, the power supply
noise significantly affects the phase noise of the output. An LM317 is not
well specified for noise and I expect is is orders of magnitude worse than
something like an LT3042 low noise regulator.

Regards,

Mark
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Vanguard TCXO

[Mark Goldberg]

On Thu, Feb 8, 2018 at 10:51 AM, jimlux <jim...@earthlink.net> wrote:

> On 2/8/18 5:34 AM, Mark Goldberg wrote:
>
>> What is the phase noise like on the cheap TCXO?Vectron
>>
>
>
> VT-702 (the first one in the list online)
> -99 at 10Hz
> -123 at 100Hz
> -143 at 1kHz
>
> going to Mouser and looking for the cheapest 10MHz TCXO
> FOX924 (about $2) - no data
> SiT5000 (about ) - -140 dBc@1kHz, -150 dBcfrom 10k to 100k, -160 @ 1M (no
> price)
> ECS -TXO-3225-100-TR ($2.71 each) - -135dBc @ 1 kHz
> ASTX-H11 ($3.16) -130dBc @ 1 kHz, -158dBc @100k
>
> FOX922CE at 16.369 MHz, -145 @ 10kHz
>
>
>
Can you provide a link to the "list online"? I went to eBay and searched
for "Vanguard TCXO" and got a list of them with various frequencies. They
all specify -125 dBc/Hz at 1 khz, which is concerning of itself, as phase
noise generally is higher with higher frequency. They are golden however,
so there's that!

Vectron and others make decent TCXOs, better than -135 dBc/Hz at 1 kHz,
which is what I have measured. I believe none of them are what the original
poster is talking about. For a comparison, a Wenzel OCXO I am using for a
reference is in the range of -155 dBc/Hz at 1 kHz.

I am always wary when no or few specifications are provided. If you look at
manufacturer;s like Vectron, they provide lots of data, phase noise at many
frequencies, aging, etc.

73,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Vanguard TCXO

[Mark Goldberg]

What is the phase noise like on the cheap TCXO? Being on frequency is far
from the only characteristic that matters. I did some research on cheap
TCXOs for Kenwood radios and found truly awful phase noise and lots of
spurs above and below the oscillator frequency. I don't know if these
characteristics are important for your unit.

One eBay source says -125 dBc/1kHz. (Should be stated as -125 dBc/Hz @ 1
kHz). That is not very good. I found the cheap TCXOs I tested actually had
worse phase noise at 15 - 20 kHz offset.

Mark
W7MLG

On Feb 8, 2018 4:24 AM, "Thomas Allgeier"  wrote:

> Hello All,
>
> This is for the medium-precision nuts amongst us. I have invested £14.50
> in one of these Vanguard 0.1ppm TCXO's to pimp my Siglent FG which has a
> footprint for it. It is its internal ref at 25 MHz. The swapping-in was
> simple to do and the FG works fine with it. Since it has a counter mode I
> did a quick check to show whether it was worthwile: I made it count the 10
> MHz from my Proteus GPSDO. The Siglent reads to 1 Hz and straight after
> turn-on it went straight to 10.00 MHz. Over about 1 day I never saw it
> more than +/-1 Hz off, and this involved a deliberate temperature change of
> just over 5 deg C, basically by having the heating in the room off and on.
> For most of the time the display sat solidly at 10.00.
>
> So, to summarise, in a rough sort of way the thing lives up to its 0.1ppm
> spec, at least around the 20C temperature mark. I bought it from a Hong
> Kong seller on Ebay - naturally there is always a chance that other devices
> sold with the same description/label might not perform as well.
>
> I'm quite aware that the generator (DDS) suffers from other sources of
> error, which won't be improved by the clock being better, but at least the
> nominal frequencies it outputs are now going to be very close to the mark
> without the need for an external ref.
>
> Kind regards,
>
> Thomas.
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] More on SiLabs 5340

[Mark Goldberg]

Reference my earlier postings titled "SI532X Chips Close In Spurs (Somewhat
Long)". There are many sets of register values that will get you the same
output frequency and the clock builder may not give you an optimal set for
phase noise and spurs. I created a spreadsheet to calculate other sets of
values and chose one that worked the best. I just did it through trial and
error of the different sets of values I came up with until I found one with
low spurs.

73,

Mark
W7MLG

On Mon, Jan 29, 2018 at 4:16 PM, John Ackermann N8UR  wrote:

> On 01/29/2018 04:54 PM, Chris Caudle wrote:
>
>> On Mon, January 29, 2018 2:38 pm, John Ackermann N8UR wrote:
>>
>>> The close-in phase noise is quite amazing, but the floor is much worse
>>> than in free-run mode.
>>>
>>
>> That phase noise plot doesn't look quite right, what PLL bandwidth did you
>> set?
>>
>
> Sorry for the earlier null reply.  I just used the settings that the
> ClockBuilder software came up with (which IIRC don't offer any choices
> about loop bandwidth in the "wizard").  I haven't yet dug into the register
> options, but I'm sure that there are ways to optimize.
>
> John
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] power supply design Re: Slightly OT: interest in a four-output, > ultra-low jitter, synthesizer block?

[Mark Goldberg]

On Thu, Jan 25, 2018 at 8:51 PM, jimlux  wrote:

> What we've done is switcher from wide range bus (9-24V) to 8V, 60 dB
> ultimate attenuation low pass, switcher 8V to 5V(e.g.), 60 db low pass,
> linear with great HF rejection (i.e. the LT3042) to 3V
>

If it is any help to someone, I did some research on low noise regulators
to drive a low phase noise oscillator. You will have to look at this in a
fixed width font. LT3042 is indeed a spectacular part with way less noise
than the baseline LT3009. Hopefully no mistakes below. Pricing is about 2
years old.


Part Manufacturer  Price  Packages   mA  Added  Added  RMS
NoiseRMS Noise Spot Noise   Noise at 100 Hz  Noise at 1000
Hz  100 Hz Noise  1000 Hz Noise
 Caps   Resistors  10 Hz -
100 kHz  100 Hz - 100 kHz  10 kHz   nV/Sqrt(Hz)  nV/Sqrt(Hz)
Ratio dB  Ratio dB

uVrmsuVrms nV/Sqrt(Hz)

LT3009   Linear Tech  SC70-8 20
150 6000
2500  0.0   0.0
LT3042   Linear Tech   $4.90  10MSOP 3x3DFN  200 2 5
0.8210
1.5   -55.6 -64.4
ADM7154  Analog Dev$5.95  8LFCSP 8SOIC   600 4
1.6  0.9   1.5  10
1.8   -55.6 -62.9
TPS7A47  TI$4.69  UQFN20 10002
4   100
20-35.6 -41.9
LP38798  TI$3.19  WSON12  4X4800 2 2
5   100
40-35.6 -35.9
LP5907   TI$0.57  SOT23-5250 1
6.5 180
50-30.5 -34.0
LP5900   TI$0.70  WSON6  150 1
6.5 300
40-26.0 -35.9
MAX8510  Maxim $1.22  SC70-5 TDFN120
2  11
300  60-26.0 -32.4
LT1962   Linear Tech   $2.39  8MSOP  300 2
20  300
80-26.0 -29.9


Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

[Mark Goldberg]

I have had very good luck with a converted toaster oven, GC-10 solder
paste, and OSH Stencils metal stencils. Basically, if the temperature
profile is good and you have good solder paste application, decent
placement, good solder mask and correct pad sizes, everything solders
itself. I have built 70 of my boards with zero solder defects. I use a 4
pin castellated part.

https://sites.google.com/site/markstcxo/
https://sites.google.com/site/markscontroleo2build/
https://drive.google.com/open?id=0B2gd5QRdoS7BVTRSNzZFTTB6RlU

In this case though, I would probably opt for the eval board at $150. I
have spent way too much time on my small board project and there are lots
of little details to getting a clean oscillator.

73,

Mark
W7MLG


On Thu, Jan 25, 2018 at 2:41 PM, Hal Murray  wrote:

>
> j...@febo.com said:
> > The challenge is that the chip is a 7x7 mm 44-QFN package and really
> wants
> > to be put on a six-layer circuit board.  That's doable, but  challenging,
> > for home assembly.
>
> Can anybody comment on the toaster oven approach?
>
> Is it practical for things like this?  How much does a solder mask cost?
> How
> much other stuff do I need?  Does the solder paste need to be refrigerated
> and other quirks like that?
>
> What are the chances of a newbie getting a 44-QFN right on the first try?
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Slightly OT: interest in a four-output, ultra-low jitter, synthesizer block?

[Mark Goldberg]

On Thu, Jan 25, 2018 at 7:32 AM, John Ackermann N8UR  wrote:
>
> After the recent discussion about Silicon Labs clock generators, I looked
at their Si5340A part and think it will be useful for a ham radio project
I'm working on.

Have you considered the Si5340-EVB development board?

https://octopart.com/search?q=si5340-evb=0

It is about $150, relatively cheap for a development board, and there is
software to program it already.

73,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP 8642 line

[Mark Goldberg]

I do not have great equipment to do the measurement but it is at least this
good at 10 MHz as measured on one of my 8642As. I can't measure phase noise
at 30 or 100 MHz.

Offset (Hz) 10 20 50 100 200 500 1,000 2,000 5,000 10,000 20,000 50,000
100,000 1,000,000
Phase Noise (dBc/Hz) -96.9 -103.0 -106.9 -109.7 -117.7 -128.4 -136.4 -140.1
-143.1 -144.9 -145.6 -145.7 -146.2 -146.6
73,

Mark
W7MLG

On Tue, Jan 23, 2018 at 4:21 PM, Ulrich Rohde via time-nuts <
time-nuts@febo.com> wrote:

>
> Who has a 10 and 30 and 100 MHz phase noise plot from 1 Hz to 1 MHz ?
> Thanks, Ulrich N1UL
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] SI5328

[Mark Goldberg]

On Mon, Jan 22, 2018 at 4:34 AM, ew via time-nuts 
wrote:

> In my opinion the SI 5328 is worth looking at for time nut application,
> like offset frequency. My problem is solder ability. Does any one know a
> source for an evaluation board or as an alternative a source that would do
> a small volume assembly?
>
> Bert Kehren
>


There is a development board. It is about $200. Search for SI5328-EVB from
the usual places.

https://octopart.com/search?q=si5328-evb=0

You can download the support software and try it out ahead of time from
here:

https://www.silabs.com/products/development-tools/timing/clock/si5328-evb-development-kit

There have been several discussions about it as part of Leo Bodanar's
GPSDOs. Search the recent archives of this list:

https://www.mail-archive.com/search?l=time-nuts%40febo.com=si5328

Mark
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] trimble Thunderbolt, how to get 25 or 27 mHz from it??

[Mark Goldberg]

I am using Leo Bodnar's GPSDO that is based on the 5328 and what looks to
be a good TCXO as an external reference clock for a Perseus SDR. Using
that, I measured phase noise and Allan Deviation of the best sources I have
available and found the phase noise and Allan Deviation to be close to what
has been measured on more expensive equipment. From a quick look at the
5351's data sheet it's jitter appears to be on the order of 100 times more
than the 5328, and would result in unacceptable phase noise for my
application.

I would expect that the 5328 with the Thunderbolt as an input source would
be even better than Leo's GPSDO. Note that the two outputs from the 5328
can't be two arbitrary frequencies, and I have found that different values
of the various dividers can produce the same output frequency by varying
levels of close in spurs.

See my sites listed below for all the details:

https://sites.google.com/site/perseusmods/
https://sites.google.com/site/perseusmods/home/performance
https://sites.google.com/site/spectrumlabtesting/

73,

Mark
W7MLG

On Sat, Jan 20, 2018 at 6:59 AM, John Ackermann N8UR <j...@febo.com> wrote:

> Hi Mark --
>
> Thanks!  To clarify, when you say you've found "it" acceptable, you're
> referring to the 5328?
>
> What caught my eye about the 5351 was the three (or eight) outputs.  My
> idea was to build a board that would provide independent LO oscillators for
> multiple VHF/UHF transverters.  It looks like the 5328 has two outputs,
> which is still useful but would require putting two or three of them on the
> board.  Which isn't the end of the world.
>
> Thanks,
> John
> 
>
>
> On 1/19/2018 8:56 AM, Mark Goldberg wrote:
>
>> On Jan 19, 2018 6:01 AM, "John Ackermann N8UR" <j...@febo.com> wrote:
>>
>> Sorry to hijack the thread, but the Si5351 looks interesting for another
>>> project I'm working on.  I know it specifies "low jitter" but has anyone
>>> looked at the phase noise?  Is it usable for RF applications?
>>>
>>>
>>
>> Datasheet states jitter in the 40-70 ps range. That is not very good. If
>> you want something suitable for RF applications, look at the Si5328. It
>> has
>> jitter on the order of 300fs.
>>
>> I believe Leo Bodnar uses it in his GPSDOs and I can confirm the phase
>> noise and Allan Deviation others have found and it is suitable for me for
>> RF applications. It is not nearly as good as the Thunderbolt though. It
>> will generate almost any frequency you want.
>>
>> Mark
>>
>>
>>
>>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] trimble Thunderbolt, how to get 25 or 27 mHz from it??

[Mark Goldberg]

On Jan 19, 2018 6:01 AM, "John Ackermann N8UR"  wrote:

> Sorry to hijack the thread, but the Si5351 looks interesting for another
> project I'm working on.  I know it specifies "low jitter" but has anyone
> looked at the phase noise?  Is it usable for RF applications?
>


Datasheet states jitter in the 40-70 ps range. That is not very good. If
you want something suitable for RF applications, look at the Si5328. It has
jitter on the order of 300fs.

I believe Leo Bodnar uses it in his GPSDOs and I can confirm the phase
noise and Allan Deviation others have found and it is suitable for me for
RF applications. It is not nearly as good as the Thunderbolt though. It
will generate almost any frequency you want.

Mark


>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] SI532X Chips Close In Spurs (Somewhat Long)

[Mark Goldberg]

On Mon, Jan 8, 2018 at 11:37 PM, Hal Murray  wrote:

> If you look at the binary of the word that goes into a DDS adder, the ones
> with more low order bits have closer in spurs.


Which of the setting is the binary word going into the DDS adder? I think
this uses a SI5328, and it is not described as a DDS chip in the data
sheet, but I am far from knowledgeable about this device.

I don't know what the output of the GPS is that goes into the SI5328.

Thanks,

Mark
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] SI532X Chips Close In Spurs (Somewhat Long)

[Mark Goldberg]

I am using the Leo Bodnar Single output Mini GPSDO to generate 38.4 MHz as
an input to a Wenzel Oscillator that locks to it and produces a low phase
noise 80 MHz to drive my Perseus SDR. The Wenzel has a low loop bandwidth
so the phase noise from the Bodnar above the 10-100 Hz range does not seem
to get through.

The issue is that there are sometimes some close in spurs from the Bodnar
that do get through, about 31 and 62 Hz on either side of the 38.4 MHz
output. I believe the GPSDO is based on a SI532X chip, as reported for the
two output version. The spurs are only about 70 dB down, maybe 15-20 dB
above the phase noise in the area.

I tried several frequency plans as the SI532X can generate the same output
with several different sets of dividers. I did find one that worked very
well, with phase noise results and Allan Deviation that appear better than
the reported phase noise for the two output version. I basically used the
Bodnar software, SI's DSPLLSIM, some spreadsheet calculations and trial and
error to determine the working frequency plan.

I was hoping someone who knows these devices might have some insight into
what the issue is and how to determine which plans will not provide close
in spurs, without requiring testing. Any suggestions are appreciated.

Below is the long part. I have listed the frequency plans I tried and the
results below. Maybe someone can see a pattern.

Thanks

Mark


*My First Try Plan *


GPS 2,560,000
N31 1
N2_HS 7
N2_LS 300
N1_HS 7
NC1_LS 20
BW 15


F3 2,560,000
Fosc 5,376,000,000


Fout 38,400,000
Fout/F3 15


*No Spurs, F3 above data sheet spec*






*My Plan with in spec F3*


GPS 2,560,000
N31 2
N2_HS 7
N2_LS 600
N1_HS 7
NC1_LS 20
BW 15


F3 1,280,000
Fosc 5,376,000,000


Fout 38,400,000
Fout/F3 30


*Spurs*






*Another Plan*


GPS 2,560,000
N31 1
N2_HS 11
N2_LS 150
N1_HS 11
NC1_LS 10
BW 15


F3 2,560,000
Fosc 4,224,000,000


Fout 38,400,000
Fout/F3 15


*No Spurs, F3 above data sheet spec*






*DSPLLSIMs Plan*


GPS 2,560,000
N31 2
N2_HS 10
N2_LS 396
N1_HS 11
NC1_LS 12
BW 15


F3 1,280,000
Fosc 5,068,800,000


Fout 38,400,000
Fout/F3 30


*Spurs*






*DSPLLSIMs Plan 2*


GPS 1,920,000
N31 1
N2_HS 5
N2_LS 576
N1_HS 8
NC1_LS 18
BW 15


F3 1,920,000
Fosc 5,529,600,000


Fout 38,400,000
Fout/F3 20


*Bad Spurs*






*DSPLLSIMs Plan 3 Using This One*


GPS 176
N31 1
N2_HS 9
N2_LS 320
N1_HS 6
NC1_LS 22
BW 15


F3 1,760,000
Fosc 5,068,800,000


Fout 38,400,000
Fout/F3 21.8181818181818


*No Spurs*
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] TAPR "PulsePuppy" Pot Selection

[Mark Goldberg]

Absolutely I see what you describe below. Bournes actually has an old paper
that describes all of these issues, but they do not seem to address them in
selection guides these days. I have no way to find out which are good until
I try 50 of them. I get a few that are just awful, basically a random
connection between the screw and the pot position.

www.bourns.com/docs/default-document-library/bourns_trimmer_primer.pdf

I have tried all kinds of tricks, going back and forth, sneaking up on it,
yes, tapping it, sweeping the wiper back and forth around the desired
setting to hopefully clean off crud from the element in that area, etc.
Some just don't want to be adjusted to a specific setting that just happens
to be on frequency. Most are fine. Some are a real pain to set where you
want.


Mark


On Sun, Dec 24, 2017 at 3:26 PM, Dana Whitlow  wrote:

> I think I need to clarify what I mean by "backlash".  It is not simple free
> play in
> the adjustment mechanism- it is something much more irritating, as follows:
>
> I sneak up on the desired result, but manage to overshoot slightly.  So I
> back
> off on the screw, and find that at first the result continues to change in
> the
> *original* direction (making the overshoot even worse) for a bit before
> finally
> reversing as I wanted it to.  This behavior is not conducive to having a
> good
> time making critical adjustments, nor does it lend any confidence in the
> stability
> of the adjustment in the face of handling.
>
> Dana
>
>
> On Sun, Dec 24, 2017 at 4:06 PM, Charles Steinmetz 
> wrote:
>
> > John wrote:
> >
> > I didn't really notice much backlash, though when setting oscillators I
> >> try to approach (slowly) from one direction until it's "good enough" and
> >> then stop, to avoid that problem.
> >>
> >
> > The hot tip is not to just "sneak[] up on the sweet spot and then walk[]
> > away," as Dana put it.
> >
> > Anytime you have an adjustment with some hysteresis (classic example is
> > setting a d'Arsonville movement to zero), you want to sneak up to the
> > perfect setting and then run the adjuster *back* the way you came just a
> > touch, to leave the adjusted part on its own without any mechanical
> > connection to the adjustor mechanism.  Such contact is almost always the
> > culprit if the adjustment drifts after you set it.
> >
> > This takes some "feel" for the motion of the adjuster mechanism, but it
> is
> > well worth investing the time to learn it by repeated trials of the
> > adjuster before you leave it alone.
> >
> > Dana is spot on with his advice to tap the board (or whatever
> mechanically
> > supports the adjusted part) to make sure it doesn't drift.  If it does,
> you
> > either failed to pull the adjuster out of contact with the moving
> adjusting
> > part, or the adjusted part just can't hold its setting.  In either case,
> > better to know that now than after you button the instrument back up.
> >
> > Best regards,
> >
> > Charles
> >
> >
> >
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/m
> > ailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] TAPR "PulsePuppy" Pot Selection

[Mark Goldberg]

I am using a Bournes 3224 and I do see backlash issues. I do come from one
direction to set it and if I overshoot, I go way past and come back from
the other direction. I also see non-monotonic sections. If one of those is
where you want to set the frequency, it is pretty hard to do. I chose one
with significantly lower impedance than the input impedance of the TCXO
control port. The 3296 datasheet has Adjustability specs and the 3224 does
not. The 3269 is only 12 turns but does have an Adjustability spec on the
datasheet. Maybe I will consider that. I would have to change my board to
use a throughole part.

Thanks for the info.

Mark


On Sun, Dec 24, 2017 at 8:58 AM, John Ackermann N8UR <j...@febo.com> wrote:

> I'm glad that the PulsePuppy post spawned some good discussion!
>
> The pot I'm using is a Bournes 3296W-1-103LF which is a 25-turn, 10K,
> cermet pot, spec'd at 100ppm/degree, so it's not anything super fancy. The
> number of turns provides decent setability, and it seems to be a good match
> for the class of oscillator the PulsePuppy is designed for -- I found that
> I could trim the Isotemp oscillator without problems.
>
> I'll admit up front that the PulsePuppy wasn't designed as a host for
> ultra-stable oscillators.  I tried to keep the circuit board size and cost
> down, as well as the number of components that users would have to
> install.  And since the EFC trimmer is one of those user-installed parts,
> it's possible to substitute as nice a pot as you'd like.  I have one unit
> that's hooked up to an external precision pot with a turn-counter dial
> (just because it was there).
>
> John
> 
>
> On 12/24/2017 03:57 AM, Mark Goldberg wrote:
>
>> Can you specify what pot you have used? I am using some for my TCXO boards
>> and am not quite happy with the settability or mechanical stability.
>> resulting in noise and higher Allan Deviation.
>>
>> A low noise regulator driving it also helped.
>>
>> I subscribe to the opinion to not use any extra resistors. When the pot is
>> used as a voltage divider, theoretically it should have the same TC
>> throughout, so temperature effects should not affect the divide ratio or
>> the output. Only the input impedance of the control voltage input to the
>> oscillator relative to the effective resistance of the pot will provide
>> some effect with temperature.
>>
>> Mark
>>
>>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] TAPR "PulsePuppy" Pot Selection

[Mark Goldberg]

Can you specify what pot you have used? I am using some for my TCXO boards
and am not quite happy with the settability or mechanical stability.
resulting in noise and higher Allan Deviation.

A low noise regulator driving it also helped.

I subscribe to the opinion to not use any extra resistors. When the pot is
used as a voltage divider, theoretically it should have the same TC
throughout, so temperature effects should not affect the divide ratio or
the output. Only the input impedance of the control voltage input to the
oscillator relative to the effective resistance of the pot will provide
some effect with temperature.

Mark
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Determining Allan Deviation From Interpolated Peak Frequency Readings

[Mark Goldberg]

On Sat, Dec 16, 2017 at 7:36 AM, Gerhard Hoffmann  wrote:

I'm about to buy a RedPitaya Stemlab 125-14. Cost is just €310 in .de,
> seems to have respectable performance, can emulate the
> GnuRadio hardware boards more or less right out of the box,
> Win  & Linux.
>
> And it is a nice stepping stone to what I really want: a bigger ZYNC
> with JESD204B support, AD9680/ADC32RF45 ADCs & AD9142 or
> similar DACs for direct L-band digitizing. No more
> phase-shifting preselector or IF filters.
> There seem to appear better ADC/DAC chips every month for Gen5.
>
> That could be a Timepod++  :-)
>
>
You know you guys are going to wind up costing me more money! The RedPitya
looks like an amazing product for the price, dual ADCs and DACs and a Zync
for that price! And, they are available at Digikey in the US for pretty
good prices. Again, a project for the future possibly.

Thanks,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Determining Allan Deviation From Interpolated Peak Frequency Readings

[Mark Goldberg]

On Sat, Dec 16, 2017 at 3:57 AM, Attila Kinali  wrote:

>
>
> Apparently the Perseus is supported by GnuRadio[1]. Which means you can
> just click your control system together (similar to LabView). According
> to [2] the driver uses libusb and works on windows as well.
>
> If you want to use GnuRadio, I suggest you go to one of the many
> Hackfests[3]
> they have and let them jump-start you (I started this way years ago).
>

There are issues with the Perseus, Windows 10 and USB3. It is hit and miss
with various software. I am not sure it would actually work with GnuRadio
on the computer I use in my Ham Radio / Electronics lab. I do have three
computers running Linux but they are elsewhere. Simon Brown has posted some
positive messages about the cause of this being found on the Perseus Forum.
Hopefully it can be fixed. The creator of the Perseus has had to move on to
other things and can only provide limited help.

It would be a big project fro me though. I have lots of projects, but will
consider it. I do have a friend that is much more of an expert with
GnuRadio.

Thanks,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Determining Allan Deviation From Interpolated Peak Frequency Readings

[Mark Goldberg]

Thanks for the detailed response.

On Fri, Dec 15, 2017 at 5:42 AM, Attila Kinali <att...@kinali.ch> wrote:

> Hey Mark
>
> On Wed, 6 Dec 2017 15:43:49 -0700
> Mark Goldberg <marklgoldb...@gmail.com> wrote:
>
> > https://sites.google.com/site/perseusmods/
> > and
> > https://sites.google.com/site/spectrumlabtesting/
> >
> > using wide FFT bins and Spectrum Lab's peak frequency interpolation
> > function. I would appreciate comments as to the effectiveness of this
> > approach. I have a thick skin, so any criticism is welcome if it improves
> > the process.
>
> The approach using FFT works, but just using the peak frequency, you throw
> away half of the data (the phase) and also limit yourself in precision
> to the bin width. It's not 100% clear that estimating the frequency
> using an FFT is unbiased in this case, thus you might get worse (or better)
> results than what the oscillator actually does.
>

Since I do not know the exact algorithm used to interpolate peak frequency,
I don't know the effect on precision. They do claim that the peak frequency
determination precision is much smaller than the bin width, which seems to
be shown by the data.

The results are good enough to discern between "bad" and "good" units under
test, but I have no way to compare my results to any other method of
measurement. This is all I have access to.


>
> What you are trying to do is spectral estimation from a limited number of
> samples. You want to have some kind of continuity, that might allow you to
> track minute changes from block you are processing to the next block.
> The easiest way to do this would be to downconvert the signal on the PC
> to zero Hz and take the phase information (simplest way: use a NCO as a
> reference, then pass the reference and signal into a CORDIC to get the
> phase
> difference). Recording this phase difference should give you a lower floor
> for *DEV than your FFT method. It will also alow you to track small phase
> changes (aka small frequency fluctuations) that happen over long periods.
> Sherman and Jördens[1] describe the approach in more detail.
>
> Other than that, the general approach looks ok.
>
>
> Attila Kinali
>
>
> [1] "Oscillator metrology with software defined radio",
> by Sherman and Jördens, 2016
> https://arxiv.org/abs/1605.03505
>

I have seen this paper before. Unfortunately, it is a lot more work to
implement than what I have already done. I am really a hardware engineer,
with decades old education in control systems that has not been used in a
long time. It would take getting my brain back in gear and re-studying, not
a bad thing actually!

The other issue is the Perseus drivers have issues under Windows 10 that
may or may not be solved. I was able to get it to work with Spectrum Lab,
but it does not work with many other tools that would be able to implement
this algorithm.

That said, I may look into it further in the future.

Mark
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Test WWV timecube against Cesium, Rubidium, MASER or other precision time (UT-1) metrology

[Mark Goldberg]

I have done some frequency measurement testing of WWV transmissions against
a not that great reference. Results are shown on

https://sites.google.com/site/perseusmods/home/performance

They are pretty awful even compared to a not that great reference. The
Ionosphere is not friendly.

Mark
W7MLG



On Thu, Dec 7, 2017 at 6:48 AM, Patrick Barthelow 
wrote:

Hello Friends,
>
>>
> I am picking up locally a couple of vintage analog Radio Shack SW time cube
>
>> radios, 70s vintage, 3 switchable SW frequencies.  Two types, the one
>
>> pictured and a Radio Shack model also that has WWV and Weather channel VHF
>
>> frequencies.
>
>> I am interested in an accurate bench test to compare the analog shortwave
>
>> radios time reporting
>
>> hopefully UT-1 against other available references.
>
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Determining Allan Deviation From Interpolated Peak Frequency Readings

[Mark Goldberg]

I am making frequency measurements as described on the following pages:

https://sites.google.com/site/perseusmods/
and
https://sites.google.com/site/spectrumlabtesting/

using wide FFT bins and Spectrum Lab's peak frequency interpolation
function. I would appreciate comments as to the effectiveness of this
approach. I have a thick skin, so any criticism is welcome if it improves
the process.

73,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[Mark Goldberg]

With help from an number of people who responded, I have gotten the Wenzel
oscillators to work and provide a frequency locked external clock to a
Perseus SDR radio. I had to add an external clock input to the Perseus and
describe it at:

https://sites.google.com/site/perseusmods/

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Regarding Wenzel PLO's

[Mark Goldberg]

On Mon, Nov 13, 2017 at 12:57 PM, Ulf Kylenfall via time-nuts <
time-nuts@febo.com> wrote:

>
> Know then that the Wenzel PLO's are sensitive to the input Power levelof
> the external reference. The datasheet says one thingbut  the phase noise
> of the locked output signal won't look very good at allif the Reference
> Power is approaching the maximum specified input level...
>

Thanks for the info. I am driving it with 38.4 MHz from an 8642A signal
generator, locked to it's 10 MHz OCXO, not perfect but it has aged pretty
well and it is within 0.1 Hz of 10 MHz. The Wenzel datasheet says nothing
about the phase noise when locked. I will adjust the input level to get the
best phase noise. Can you tell me how far off 100 MHz it is when unlocked?
I am trying to determine if mine is typical or partially broken.

Thanks again,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[Mark Goldberg]

On Sun, Nov 12, 2017 at 7:02 PM, Mark Goldberg <marklgoldb...@gmail.com>
wrote:

>
> On Sun, Nov 12, 2017 at 6:38 PM, John Miles <j...@miles.io> wrote:
>
>>
>> Most of the 100 and 200 MHz bricks I've seen work with either 5 or 10 MHz
>> .  I don't know if I've seen any 80 MHz units that do.  All of the ones
>> I've bought on eBay have been from the customer-proprietary 500- series
>> with unusual input frequencies.
>>
>>
> I swept the input from 1 to 100 MHz. They lock at 38.4 MHz in. Yes they
> are 4-5 kHz off when free running. Locked they are right on frequency.
>
> Mark
>
>
I have one more question.  Does anyone know if when unlocked it is possible
to apply a tuning voltage to the Phase Lock Voltage monitor pin? What good
is it to have an OCXO that needs to lock to a external frequency and is 4
kHz off when unlocked? When locked, it comes up on frequency from first
power on, so why would an oven be needed at all?

If interested, take a look at my qrz.com page for links as to why I am
doing this. I have fallen down the rabbit hole of more accurate frequency!

Thanks,

Mark
W7MLG
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[Mark Goldberg]

On Sun, Nov 12, 2017 at 6:38 PM, John Miles  wrote:

>
> Most of the 100 and 200 MHz bricks I've seen work with either 5 or 10 MHz
> .  I don't know if I've seen any 80 MHz units that do.  All of the ones
> I've bought on eBay have been from the customer-proprietary 500- series
> with unusual input frequencies.
>
>
I swept the input from 1 to 100 MHz. They lock at 38.4 MHz in. Yes they are
4-5 kHz off when free running. Locked they are right on frequency.

They don't spec the phase noise when locked. I hope it is decent. The phase
noise when unlocked is pretty good. I can only measure the phase noise
indirectly by driving my Perseus clock with this and comparing phase noise
measurements when using the internal clock. I may wind up using the
internal clock when measuring phase noise and this when measuring Allan
Deviation.

Thanks for the suggestions.

Mark
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[Mark Goldberg]

Yes, exactly those. With no input, would they be expected to be 4 kHz off?
The spec for the standard part wants the input to be within 1e-7. I would
not expect them to be so far off free running.

I saw 13 MHz on the 500-14273 and stayed away from those.

Do you know of any part numbers that use 10 MHz in? Wenzel would not tell
me the exact specs of the 500 series parts available on ebay and only sent
me the specs for the standard 501-14057 that takes 10 MHz.

I have a couple 8642As and can generate any frequency I want with decent
phase noise, locked to my 10 MHz reference. I could try these frequencies
above.

Do you know what the pll lock output does when the input frequency is off?
These toggle high for any frequencies I have put in.

Any other ideas are appreciated.

Thanks,

Mark


On Sun, Nov 12, 2017 at 5:19 PM, John Miles <j...@miles.io> wrote:

> Sounds like he's talking about the small 'bricks' that Wenzel sells with
> internal PLL-disciplined OCXOs.  Some of these expect oddball input
> frequencies.  Just looking at the 80 MHz parts on the shelf around here,
> 500-14273 wants a 13 MHz input, 500-25010 uses 24.576 MHz, and 500-25009
> uses 19.2 MHz.   So that's probably the issue, if two of them seem to be
> failing the same way.
>
> -- john, KE5FX
> Miles Design LLC
>
>
> > -Original Message-
> > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
> > Camp
> > Sent: Sunday, November 12, 2017 2:03 PM
> > To: Discussion of precise time and frequency measurement
> > Subject: Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency
> >
> > Hi
> >
> > I guess my point was more that there is not a VCO / PLL combo in an OCXO.
> >
> > If dropping the supply gets you on frequency, then you have moved things
> a
> > lot
> > with that voltage change. 50 PPM is a lot of delta T on any normal OCXO
> > crystal.
> > That strongly suggests there is something wrong in the control circuit.
> >
> > Bob
> >
> > > On Nov 12, 2017, at 2:52 PM, Mark Goldberg <marklgoldb...@gmail.com>
> > wrote:
> > >
> > > The standard oscillator, 501-14057 (
> > > www.wenzel.com/wp-content/parts/501-14057.pdf) will lock to an
> > external 10
> > > MHz reference and this one is marked "80 MHz" and "15V on the label.
> > Maybe
> > > someone swapped the labels. I did try lowering the supply voltage. It
> got
> > > to 80 MHz at about 11V and still did not lock to the reference. This
> > > oscillator is specified at 1e-6/year aging. That is way less than it
> is off
> > > now.
> > >
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[Mark Goldberg]

The standard oscillator, 501-14057 (
www.wenzel.com/wp-content/parts/501-14057.pdf) will lock to an external 10
MHz reference and this one is marked "80 MHz" and "15V on the label. Maybe
someone swapped the labels. I did try lowering the supply voltage. It got
to 80 MHz at about 11V and still did not lock to the reference. This
oscillator is specified at 1e-6/year aging. That is way less than it is off
now.

Mark

On Sun, Nov 12, 2017 at 12:34 PM, Bob Camp <kb...@n1k.org> wrote:

> Hi
>
> It’s pretty certain that there is no PLL inside an 80 MHz low phase noise
> OCXO.
> If it is 4 KHz off frequency at 80 MHz, that gets you into the 50 ppm
> range. Either
> it is running on a really odd crystal spur or it’s not at the right
> temperature. Drifting
> around by 100’s of Hz ( = ppm’s at 80 MHz) is also a good indication that
> the oven
> is not doing it’s job correctly.
>
> If multiple units do the same thing, either they all got busted being
> puled from gear
> (unfortunately that’s common) or you are running it at the wrong supply
> voltage.
>
> Bob
>
>
>
> > On Nov 12, 2017, at 1:19 PM, Mark Goldberg <marklgoldb...@gmail.com>
> wrote:
> >
> > The seller has replaced it with one that does the exact same thing, which
> > is weird to have two fail in the same way. They are getting hot and the
> > frequency varies with the input voltage, so I tended to guess not the
> > heater as I don't think it could pull that far over temp, and it always
> is
> > high. If it has an unlocked PLL on the output, with no control, would it
> go
> > to the max frequency? Since the seller seems to be reasonable, I was
> trying
> > to figure out best not to waste both of our's time, and me get a good
> unit
> > and them getting a sale.
> >
> > Mark
> >
> >
> > On Sun, Nov 12, 2017 at 9:22 AM, Bob Camp <kb...@n1k.org> wrote:
> >
> >> Hi
> >>
> >> As a guess - the oven circuit has stopped working. Next step
> >> would be to tear it open and trace out the schematic. After that
> >> make reasonable guesses for any parts that are poorly labeled.
> >>
> >> Much of what shows up on eBay has been through the ringer in
> >> China. A high percentage the OCXO's I get on eBay show up with
> >> issues as a result. There is no way to be sure this or that part was
> >> ok before it came out of the gear it was in. It’s always a gamble.
> >>
> >> Bob
> >>
> >>> On Nov 12, 2017, at 10:41 AM, Mark Goldberg <marklgoldb...@gmail.com>
> >> wrote:
> >>>
> >>> I have obtained a couple 80 MHz Wenzel Oscillators P/N 500-16423A. They
> >> are
> >>> proprietary but similar to the VHF PLO and 501-14057 Oscillators. I
> want
> >> to
> >>> use this to replace the internal oscillator in my Perseus SDR, for
> better
> >>> accuracy and maybe better phase noise. Both of these are way off in
> >>> frequency, about 4-5 kHz high from the ideal 80 MHz, and drift around
> >>> hundreds of Hz. I believe they are broken in some way. The PLL lock
> >> signal
> >>> toggles when I put an input into the 10 MHz reference, but the output
> >>> frequency is not affected.
> >>>
> >>> Wenzel has answered some of my questions, but can't get specific as
> these
> >>> are proprietary to a customer.
> >>>
> >>> Any experts on these oscillators out there?
> >>>
> >>> Thanks,
> >>>
> >>> Mark
> >>> ___
> >>> time-nuts mailing list -- time-nuts@febo.com
> >>> To unsubscribe, go to https://www.febo.com/cgi-bin/
> >> mailman/listinfo/time-nuts
> >>> and follow the instructions there.
> >>
> >> ___
> >> time-nuts mailing list -- time-nuts@febo.com
> >> To unsubscribe, go to https://www.febo.com/cgi-bin/
> >> mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[Mark Goldberg]

The seller has replaced it with one that does the exact same thing, which
is weird to have two fail in the same way. They are getting hot and the
frequency varies with the input voltage, so I tended to guess not the
heater as I don't think it could pull that far over temp, and it always is
high. If it has an unlocked PLL on the output, with no control, would it go
to the max frequency? Since the seller seems to be reasonable, I was trying
to figure out best not to waste both of our's time, and me get a good unit
and them getting a sale.

Mark


On Sun, Nov 12, 2017 at 9:22 AM, Bob Camp <kb...@n1k.org> wrote:

> Hi
>
> As a guess - the oven circuit has stopped working. Next step
> would be to tear it open and trace out the schematic. After that
> make reasonable guesses for any parts that are poorly labeled.
>
> Much of what shows up on eBay has been through the ringer in
> China. A high percentage the OCXO's I get on eBay show up with
> issues as a result. There is no way to be sure this or that part was
> ok before it came out of the gear it was in. It’s always a gamble.
>
> Bob
>
> > On Nov 12, 2017, at 10:41 AM, Mark Goldberg <marklgoldb...@gmail.com>
> wrote:
> >
> > I have obtained a couple 80 MHz Wenzel Oscillators P/N 500-16423A. They
> are
> > proprietary but similar to the VHF PLO and 501-14057 Oscillators. I want
> to
> > use this to replace the internal oscillator in my Perseus SDR, for better
> > accuracy and maybe better phase noise. Both of these are way off in
> > frequency, about 4-5 kHz high from the ideal 80 MHz, and drift around
> > hundreds of Hz. I believe they are broken in some way. The PLL lock
> signal
> > toggles when I put an input into the 10 MHz reference, but the output
> > frequency is not affected.
> >
> > Wenzel has answered some of my questions, but can't get specific as these
> > are proprietary to a customer.
> >
> > Any experts on these oscillators out there?
> >
> > Thanks,
> >
> > Mark
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Wenzel VHF PLO Oscillators Off Frequency

[Mark Goldberg]

I have obtained a couple 80 MHz Wenzel Oscillators P/N 500-16423A. They are
proprietary but similar to the VHF PLO and 501-14057 Oscillators. I want to
use this to replace the internal oscillator in my Perseus SDR, for better
accuracy and maybe better phase noise. Both of these are way off in
frequency, about 4-5 kHz high from the ideal 80 MHz, and drift around
hundreds of Hz. I believe they are broken in some way. The PLL lock signal
toggles when I put an input into the 10 MHz reference, but the output
frequency is not affected.

Wenzel has answered some of my questions, but can't get specific as these
are proprietary to a customer.

Any experts on these oscillators out there?

Thanks,

Mark
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.