Re: [time-nuts] HP5065a cfield issue

Hi Ok, if the synth is off the “suspect” list …. *and* it’s a good solid lock. Back to the C field. If it jumped 4x10^-11, that’s a very different thing than jumping 2x10^-9. Finding the “source” of a 0.04 ppb shift is going to be a lot harder than finding a 2 ppb gotcha. Best to nail down

Re: [time-nuts] HP5065a cfield issue

. All sorts of things > can drift with this setup. > Will use a 5371b counter later tonight and get serious. > But that said have I actually lost a bit in the synthesizer. In the > diagrams, looks like diodes and other ancient devices to consider. > Regards > Paul > > On Tue, Dec 1

Re: [time-nuts] HP5065a cfield issue

Hi …… the synth output comes right out of the BNC on the front panel. Pretty easy to hook a counter to. Also a good place to feed in an external synth. Bob > On Dec 1, 2020, at 2:11 PM, paul swed wrote: > > Corby I like the 3325 suggestion. I have a 3335 that I can lock together > with

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Hi You are going to fabricate the “base” as a solid piece. Getting a coax style connector into that is just a matter of your credit limit. The larger issue on the device is making the “cover” out of metal. That probably isn’t going to work very well :) Now you are off into a glass cover of

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Hi The gotcha with the device in question is that roughly 90% of the volume is in the microwave path to the antenna. Most of the remaining 10% if filled with electronics …. One (as yet unmentioned) solution is to equip the device with an air inlet *and* a small bleed hole. You

Re: [time-nuts] HP5065a cfield issue

measurements. Will have to look them up. > Regards > Paul. > > On Tue, Dec 1, 2020 at 8:51 AM Bob kb8tq wrote: > >> Hi >> >> The C field coil resistance is low enough that you have something in the >> vicinity >> of 10mv across it. If you want to c

Re: [time-nuts] EOL Motorola Oncore Remote Antenna

Hi > On Nov 30, 2020, at 6:08 PM, jimlux wrote: > > On 11/30/20 1:22 PM, Art Sepin wrote: >>> To me it looks more like water ingress through micro-cracks in the >>> plastic-dome, and the O-ring did its job and kept that water in. >> Interesting. That's the first we've heard about micro-cracks

Re: [time-nuts] HP5065a cfield issue

Hi The C field coil resistance is low enough that you have something in the vicinity of 10mv across it. If you want to check the C field regulator, I’d just pop a wire and put a meter in series with the coil. My bet: your synthesizer has slipped a bit somewhere. I’d check it’s output against

Re: [time-nuts] Early Christmas - DMTD up and running

Hi When doing DMTD “noise floor” with a common oscillator, you need to use a “line stretcher” between the inputs to the DMTD. In the case of a 5 MHz system, you would need about 30 to 50’ of coax to get the job done. There is no need for infinitely fine steps, a set of 3 cables at 20 / 10 / 5

Re: [time-nuts] Voyager space probe question

Hi The Voyger probes are very complex setups. There are a *lot* of frequency references in them. The “on the ground” rover happens to have used a Vectron TCXO …. Bob > On Nov 28, 2020, at 5:06 PM, donald collie wrote: > > Can any group member describe the onboard frequency reference[s] used

Re: [time-nuts] Well priced GPSDO that outputs IRIG-B

Hi My concern would be the level of documentation that comes with the part. There are (obviously) a lot of external connections required to get it to do all they claim. I would think that documenting all that variability would be a fairly involved task …. It’s also not quite clear if there is

Re: [time-nuts] SMPS or conventional?

AE%B1bd4kc%40126.com%22%5D>签名由 > 网易邮箱大师 <https://mail.163.com/dashi/dlpro.html?from=mail88> 定制 > > On 11/23/2020 22:15, Bob kb8tq <mailto:kb...@n1k.org> wrote: > Hi > > There are two “zones” in the typical Rb physics package. They both need to be > hea

Re: [time-nuts] SMPS or conventional?

Hi There are two “zones” in the typical Rb physics package. They both need to be heated. Unfortunately they need to be heated to *different* temperatures. This makes for an interesting design. Insulate things to well and the one that is supposed to be at a slightly lower temperature is heated

Re: [time-nuts] DMTD and data display

Hi > On Nov 22, 2020, at 2:40 AM, Tom Van Baak wrote: > > Hi Skip, > > The input menu for both TimeLab and Stable32 allow you to set tau0 and also > the phase scaling factor. Given your choice of frequencies your sample rate > will be 10 Hz, so set tau to 0.1 s. And, yes, the scaling factor

Re: [time-nuts] Survey grade antennas

Hi If you dig into the data on the antennas …. ( they are fully tested and doccumented …) The Novatel design does a *very* good job. Indeed they are *much* better than an old style giant choke ring design. Normal list price is roughly 10X what that listing shoed. Similar antennas normally

Re: [time-nuts] Survey grade antennas

Hi ….. and now they all seem to have been sold :) Thanks for the heads up !!! Bob > On Nov 18, 2020, at 3:56 AM, Stewart Cobb wrote: > > The usual auction site has a few true survey grade antennas for a very good > price. Search for Novatel GPS-703-GGG. These cover all three frequency >

Re: [time-nuts] Z3801A Replacement GPS Receiver

Hi I don’t recall any hand held version of the *timing* version of the Oncore …. Indeed with all of the roll over issues on top of the original Oncore’s limitations, shopping with Art is probably your best choice. A lot has gone on in the GPS receiver world over the last 20 years …. Bob > On

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

Hi It’s *lots* easier to apply it in software than to do the fun and games with the delay line. One of the biggest issues with the delay line approach is finding one that is good enough ( stable, 0.1 ns resolution, wide enough range, low noise ….) to do the job. Bob > On Nov 10, 2020, at

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

> enclosure and there are DC-DC converters for power, Nucleo processor > running at 140MHz, a NEXTION touch screen LCD, which > I am discovering is very noisy, etcIt is difficult to target any > solution at the moment as I believe there are too many areas that are > marginal - I

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

Hi Are you using sawtooth correction? Bob > On Nov 10, 2020, at 8:55 AM, Joe & Gisela Noci wrote: > > Hi everyone, > Still playing with my GPSDO..The Rubidium source I was hoping to have the > loan off did not work out, so still in the dark. I have sort of convinced > myself to procure a

Re: [time-nuts] Small NTP appliance

Hi If this is a scratch build without using the typical software, pretty much anything could be done. As noted earlier, the “normal” way to do this is to go to something that will run some flavor of Linux. On a practical basis, you *could* have a good antenna location for your GPS. That

Re: [time-nuts] Efratom M100 Found on Ramco auction site.

a side business repairing Rb modules, but in the > end the carriers just wanted to know they had a new module, not a repaired > module. > > No basements here in Texas, so am jealous of the concept! > > The Fiber Guru > www.fiber.guru > > >> On Nov 2, 2020, at 6:16

Re: [time-nuts] Efratom M100 Found on Ramco auction site.

Hi One of the nice things about the broad reach of this list is that a pretty good “database” of device performance can be compiled. In addition there *is* the fact that even Rb’s can be repaired. The “toss it when it breaks” approach is not a favorite with most list members. I have seen no

Re: [time-nuts] OCXO housings - Why copper and not iron/steel?

Hi ….. and of course, there was an OCXO that used a beryllium oxide substrate in pretty much the same way (inner oven in a double oven). Same basic issues and not exactly cost effective. The alumina substrate lives on in a number of miniature oven designs. Bob > On Nov 1, 2020, at 5:20 AM,

Re: [time-nuts] WWVB teensy BPSK early experiments

Hi > On Oct 31, 2020, at 9:45 PM, jimlux wrote: > > On 10/31/20 4:46 PM, Bob kb8tq wrote: >> Hi >> Looking at the data sheet for the MCU, they really do want 24 MHz and that’s >> about it. I suspect you would >> do better to take your 10 MHz OCXO and

Re: [time-nuts] WWVB teensy BPSK early experiments

y and will need to use a scope at this point to see > the effects. > Regards > Paul. > > > On Sat, Oct 31, 2020 at 7:35 PM jimlux wrote: > >> On 10/31/20 11:42 AM, Bob kb8tq wrote: >>> Hi >>> >>> …..errr….. >>> >>> Can you

Re: [time-nuts] WWVB teensy BPSK early experiments

of stuff to hack up. Bob > On Oct 31, 2020, at 7:17 PM, jimlux wrote: > > On 10/31/20 11:42 AM, Bob kb8tq wrote: >> Hi >> …..errr….. >> Can you pull the clock oscillator off the Teensy board? (Yes, the soldering >> iron would be involved). >> Will the clock

Re: [time-nuts] WWVB teensy BPSK early experiments

Hi …..errr….. Can you pull the clock oscillator off the Teensy board? (Yes, the soldering iron would be involved). Will the clock input to the MCU accept something like 10 MHz? If so solder on a cable …. At that point whatever the Teeny does is locked to the 10 MHz. If that comes from one of

Re: [time-nuts] OCXO housings - Why copper and not iron/steel?

Hi Gradients are a really big deal in an OCXO. Thermal mass works against you if you are after quick warmup …. Bob > On Oct 30, 2020, at 6:23 PM, Attila Kinali wrote: > > On Fri, 30 Oct 2020 17:58:24 -0400 > Bob kb8tq wrote: > >> Simple answer: conductivity. You don’t g

Re: [time-nuts] OCXO housings - Why copper and not iron/steel?

Hi Simple answer: conductivity. You don’t get much heat capacity either way. Bob > On Oct 30, 2020, at 5:49 PM, Attila Kinali wrote: > > Moin, > > I have been looking at heat capacities of different materials > lately. One thing that struk me odd is, that the volumetric > heat capacity of

Re: [time-nuts] HP 5345A Noise Floor

Hi Ummm ….. er …… not so much :) The time base of the counter is only just so good. I would guess that there is a glitch somewhere in the data transfer / data file formatting. Bob > On Oct 30, 2020, at 1:14 PM, Giorgio Barinetti wrote: > > Hi Bob, > > > > The current setup is: >

Re: [time-nuts] "When you google word ..."

Hi So there might be a reason (other than NIST) to believe that frequency and gravity are related to each other ? :) Bob > On Oct 30, 2020, at 7:28 AM, Tom Van Baak wrote: > > > Time Too Good to Be True, Daniel Kleppner > > Physics Today, March 2006, page 10 > >

Re: [time-nuts] SiTime Stratum 3E DCOCXO

Hi Indeed, they are pretty amazing for a tiny little part. Ultimately physics does catch up with them. The resonator in the heart of the device has it’s limitations compared to a big chunk of quartz. Things like ADEV or phase noise aren’t their strong suit when compared to a good OCXO. Note

Re: [time-nuts] HP 5345A Noise Floor

Hi According to page 1-3 in https://bama.edebris.com/download/hp/5345a/5345a_6.pdf The 5345 is a 2 ns counter. Roughly speaking, that normally gets you around 2x10^-9 at 1 second. That would suggest there is something a bit off in your

Re: [time-nuts] ES100 Atomic Clock Receiver Back in Stock

Hi Just to be complete: They also have the “modules” as well. You can buy the full up Arduino device with display or (for less money) just the little board with the chip and a few vital parts on it. They claim to be testing 3,000 of them ….. Bob > On Oct 29, 2020, at 7:56 AM, Ben Hall wrote:

Re: [time-nuts] power supply for Z3801

Hi I think you will find that most of this gear came in two voltage ranges. One version ran from about 20V to about 34V The other version ran from about 36V to about 56V. The first one gets called 24 or 28V. The second one gets called 48V. Both *should* be able to run off a pretty basic supply.

Re: [time-nuts] power supply for Z3801

Hi Take a look at https://www.trcelectronics.com/mean-well-power-supplies before you decide. Their prices on MeanWell are normally pretty good. Since they are an authorized distributor, you can be pretty sure you are getting legit

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

Hi I’m pretty sure you can find multiple posts from me spelling it any of a half dozen ways ….. :) Bob > On Oct 27, 2020, at 9:29 PM, jimlux wrote: > > On 10/27/20 6:16 PM, Tom Van Baak wrote: >> Alberto, >> Thanks for asking. The correct spelling is Allan variance or Allan >> deviation,

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

even ship toNamibia! > > Having learned a lot from you chaps, for which I am grateful, I think I now > at least know the size of the cliff above of me! > > > Thanks to all.. > regards > Joe > > On Tue, Oct 27, 2020 at 3:29 PM Bob kb8tq wrote: > >>

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

Hi What are we trying to measure with ADEV? On a frequency source, it’s used to measure the noise of that source. Mostly we put up plots of ADEV to show how quiet our source is. (Yes, we might also measure noise floor or amplifier contributions ….). That’s the statistics part. Now for the

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

( this is the number of points in the file) > So 141879 seconds is 1day 15hours, but the plot X Axis shows 2 > seconds... > > I cannot find anything wrong with the sample data - no missing samples, etc. > Is this not representing the averaging process? > > Thank You again for

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

than you probably should be counting on to be useful. Bob > > I cannot find anything wrong with the sample data - no missing samples, etc. > Is this not representing the averaging process? > > Thank You again for your explanations! > Joe > > > On Mon, Oct 26,

Re: [time-nuts] Rapco 1804M manual and Control Mode Access ?

Hi Normally a date roll over bug is a non-fixable item in these older devices. The basic GPS modules simply did not start to have the “smarts” to handle this until at least a decade after they went out of production. Simple answer is to leave it as is and just use the frequency output. If you

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

hips yet.. A lot of this is simply getting the data into a form that this or that program “likes”. It’s just a lot of tweaking and seeing if the result comes out right. Bob > > Thank You! > Joe > > > On Mon, Oct 26, 2020 at 4:21 PM Bob kb8tq wrote: > >&g

Re: [time-nuts] Mentorship needed in learning about Allan Deviation and variation.

Hi Any practical measure you feed into an ADEV computation will be a look at “device A” versus “device B”. In this case one of them is your GPSDO. What is the other device? ( = your TIC has a DUT input and a REF IN, it compares one to the other ….). If you feed your measurement system with the

Re: [time-nuts] 5065A Rb Cavity Rx - SRD repair

Hi As part of your “simple replacement” … keep in mind that it needs to act both as a multiplier *and* as a mixer. The two modes need to be reasonably separate from each other or you (likely) get a real mess. Bob > On Oct 25, 2020, at 4:26 PM, Ulf Kylenfall via time-nuts > wrote: > > >

Re: [time-nuts] Assistance needed to understand some V_OCXO stability concepts.

it. > > I let it run for 4 days to settle a little, and did a 12 hour run recording > the output from the (analogue) TIC. > Attached is the Adev per TimeLab...will run for a week or so and see what > develops. > > Thanks so far to all the people who have commented and steered my &

Re: [time-nuts] Looking for "The Theory and Design of Quartz Crystal Units" by V.Bottom

Hi > On Oct 25, 2020, at 3:43 AM, Bernd Neubig wrote: > > > > Hi, > >> On Fri, 23 Oct 2020 19:32:16 -0400 >> Bob kb8tq wrote: >> Those authors pretty much only focus on *oscillator* design. ( = >> electronics). >> Bottom is a “crystal guy

Re: [time-nuts] Query about insulated coax panel connectors?

Hi Mini-circuits will sell you the transformers already in a box. Needless to say, they do charge a bit for that. Occasionally, you can find them on eBay for a more rational price. If you are going the DIY route, incorporating a couple of common mode chokes on both sides of the transformer is

Re: [time-nuts] Looking for "The Theory and Design of Quartz Crystal Units" by V.Bottom

Hi The gotcha is that if you want to *use* what’s in that book ( I have a copy and went to the course back in the 1970’s) the first step is to grab a chunk of quartz. Next you head over to your X-ray setup and work out what you have. After that you go over to the saw and chop some raw blanks.

Re: [time-nuts] Looking for "The Theory and Design of Quartz Crystal Units" by V.Bottom

Hi > On Oct 24, 2020, at 7:43 AM, Attila Kinali wrote: > > On Fri, 23 Oct 2020 19:32:16 -0400 > Bob kb8tq wrote: > >> This book is an introduction to designing AT cut resonators. It came out >> before the SC existed. It’s very much a “starter” book on the subject.

Re: [time-nuts] Looking for "The Theory and Design of Quartz Crystal Units" by V.Bottom

Hi >From what I can see, all are essentially editions of the same book, updated as he continued to do his classes. Bob > On Oct 23, 2020, at 9:50 PM, Wes wrote: > > Attila, > > Amazon says (Out of print): > > * Publisher : McMurray Press; 1st Edition (January 1, 1968) > * Language: :

Re: [time-nuts] Looking for "The Theory and Design of Quartz Crystal Units" by V.Bottom

Hi > On Oct 23, 2020, at 5:11 PM, Attila Kinali wrote: > > Moin, > > I'm again hunting for some old stuff. Quite a few older papers, > books and technotes (including an article by Bernd Neubig from 1978) > reference V.Bottom's "The Theory and Design of Quartz Crystal Units" > from 1974 This

Re: [time-nuts] SMPS or conventional?

Hi I must admit, the longevity of the compressor based setup in the typical kitchen fridge continues to amaze me. :). === TEC’s have a fairly limited “pumping range”. It is not uncommon to discover you need to stack them to get this or that job done. We wound up with a stack of 5 to get

Re: [time-nuts] Frequency Counter Choice

Hi …. and now I have a copy :) Bob > On Oct 22, 2020, at 6:12 PM, Attila Kinali wrote: > > On Thu, 22 Oct 2020 13:29:07 -0400 > Bob kb8tq wrote: > >> There is a paper running around behind the IEEE paywall by Collins that >> details >> one approach

Re: [time-nuts] 5065A Rb Cavity Rx - SRD repair

Hi The SRD is not easily accessible. Digging in to get it is going to involve a bit of work. The power level is going going to be a function of the cavity design. Apparently that design is “non-standard” so any number will be a guess. The 5065 manual shows typical RF voltage levels into the

Re: [time-nuts] Frequency Counter Choice

Hi One approach to a mixer setup is the DMTD (dual mixer time difference). It has a “little cousin” that also does very will running one mixer instead of two. The limit there being that you need to be able to tune one or both the devices you are testing to get a beat note in the 2 to 10 Hz

Re: [time-nuts] Frequency Counter Choice

rious how viable would it be to use a 531xx series counter with > Timelab if the counter display has failed ? > > Thanks in advance > > Mark Spencer > m...@alignedsolutions.com > 604 762 4099 > >> On Oct 22, 2020, at 6:36 AM, Bob kb8tq wrote: >> >> Hi >

Re: [time-nuts] 5065A Rb Cavity RX - Varactor repair?

Hi The device in the cavity that takes the 60 MHz up to 6.x GHz is a step recovery diode ( SRD ). The actual device used (apparently) was unique to the 5065. One proposed “fix” is to eliminate the whole synth / multiply empire and replace it with a very high resolution DDS generating the 6.x

Re: [time-nuts] Frequency Counter Choice

Hi > On Oct 22, 2020, at 7:50 AM, Giorgio Barinetti wrote: > > Hi, > > As a newbie in the field, I've collected, by chance, some frequency standards. > > Now is the time to measure them, and see how they perform. > > I've inherited a 5371, but something tells me that is not the right >

Re: [time-nuts] SMPS or conventional?

Hi The magnetic field sensitivity is dependent on a lot of things. Strangely enough, the higher the C field, the more sensitive the physics package is ( yes, that’s weird …). All Rb’s incorporate shielding to reduce the external field impact. Since the shielding is rarely perfect, there are

Re: [time-nuts] SMPS or conventional?

Hi TEC’s are indeed prone to wear out. That said, so is a compressor ….. Bob > On Oct 22, 2020, at 12:36 AM, Hal Murray wrote: > >> like with TEC heat/cool capability > > What's the typical MTBF of TEC coolers? How much does it depend on how much > power you put through them? > > -- >

Re: [time-nuts] IEEE 1588 PTP support on raspberry pi 4 compute module

Hi > On Oct 21, 2020, at 7:28 PM, Wojciech Owczarek > wrote: > > Hi Bob, > > On Wednesday, 21 October 2020, Bob kb8tq wrote: > > >> *Networking* hardware is the issue ….. >> > > Undeniably so, but to what extent? Simply that you can get i

Re: [time-nuts] IEEE 1588 PTP support on raspberry pi 4 compute module

n/out support) or PC Engines' APU1/APU2 with > multiple(!) Intel PHYs.All of these support PTP. > > Some comments to Bob's reply: > > On Tue, 20 Oct 2020 at 23:08, Bob kb8tq wrote: > >> Hi >> >> Two very separate chunks to this: >> >> T

Re: [time-nuts] SMPS or conventional?

Hi The only issue with the “controlled fan” approach is that you have a variable magnetic field as a result. That and the vibration both can impact the stability of the Rb. Some means of isolating the fan from the immediate vicinity of the Rb sounds like a good idea. Bob > On Oct 21, 2020, at

Re: [time-nuts] SMPS or conventional?

Hi > On Oct 21, 2020, at 8:40 AM, Wannes Sels wrote: > > There are conflicting requirements regarding temperature in Rb's: > > - For best performance, the rubidium and quartz oscillators must be kept at > a high and stable temperature. > - For reliability, the supporting electronics must be

Re: [time-nuts] SMPS or conventional?

Hi The devices all *worked* just fine, even without any heatsink at all. There was no performance impact to the (lack of) heatsink in a normal lab environment. Small in this case is mounting the device to a heatsink that is the size of the “hot” side and maybe a half inch of fins. Fins always

Re: [time-nuts] SMPS or conventional?

Bob > Before I read the previous tread, I was thinking of electronic thermostat/fan > but... > > Em 20/10/2020 10:34, Bob kb8tq escreveu: >> Hi >> >> Not very well organized message here …. I’m still working on my first cup of >> coffee …:) >> >> Fi

Re: [time-nuts] Time and tide - pendulum clocks and gravity tides

Hi Isn’t there a picture of TVB doing something to that clock? :) Bob > On Oct 19, 2020, at 5:30 PM, Hal Murray wrote: > > Speaking of pendulums... > > BBC: The Clock That Changed the World (BBC History of the World) > https://www.youtube.com/watch?v=T-g27KS0yiY > 29 minutes > > Fantastic

Re: [time-nuts] SMPS or conventional?

Hi What will the output of the box be used for? If low phase noise is an objective, then one needs to be pretty careful about power supply noise. If low phase noise is not a “need” in this case, then (good) switchers can be used for everything. What’s a “good” switcher? You want one that is

Re: [time-nuts] Droitwich Frequency Error

Hi > On Oct 18, 2020, at 10:07 AM, Andy Talbot wrote: > > Hi Folks > I've just joined this list, but have had an interest in accurate frequency > measurement for decades, ever since finding a fully operational HP5061A in > skip with what appears to be plenty of Cs life left in the tube. It

Re: [time-nuts] Assistance needed to understand some V_OCXO stability concepts.

XCO - 101' experience levels, but > thanks for the help! No problem …. happy to help. Bob > > Thanks again! > Regards > Joe > > On Sun, Oct 18, 2020 at 12:31 AM Bob kb8tq wrote: > >> Hi >> >> (see below) >> >>> On Oct 17, 2020, at 4:

Re: [time-nuts] Assistance needed to understand some V_OCXO stability concepts.

hould* be taken out by the GPSDO function …. Things that take minutes (or maybe an hour) are what will make things messy. Drafts and other transient temperature effects are the target here. Bob > > Regards > Joe > > > On Sat, Oct 17, 2020 at 6:54 PM Bob kb8tq wrote: > >>

Re: [time-nuts] cheap frequency extension for timepod

Hi I would *think* that the phase noise out of the down converter channel would be the DUT + LO. If indeed you have DUT A + LO B and DUT C + LO D, you then have a lot of A + B vs C + D stuff to sort out …. Bob > On Oct 17, 2020, at 2:48 PM, John Ackermann N8UR wrote: > > FWIW, I have done

Re: [time-nuts] cheap frequency extension for timepod

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

Re: [time-nuts] cheap frequency extension for timepod

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: >

Re: [time-nuts] Assistance needed to understand some V_OCXO stability concepts.

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

Re: [time-nuts] 5065A phase noise

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

Re: [time-nuts] WWVB Dephaser Question

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: &

Re: [time-nuts] WWVB Dephaser Question

Hi The “simple” approach is to generate the full modulation pattern for the signal based on a “known good” time source. There are a couple of ambiguous bits so it will only be close. Feed that into your inverter and the result will be (near) clean WWVB. Since you never demodulate the WWVB,

Re: [time-nuts] WWVB Dephaser Question

E. < >> j...@westmorelandengineering.com> wrote: >> >>> Bob, >>> >>> Thanks for the answer; but does anyone actually have a documented >>> specification posted for one of these 'massive' WWVB 60kHz antennas >>> someplace? >>> >&g

Re: [time-nuts] WWVB Dephaser Question

o that option is out. I haven't > made a decision on the CPU yet. I will just use whatever it takes for > the job, probably a STM32 part of some sort. I have a couple of STM32 > development boards I can use when I get to that point. > > Ray > > > Original Message --

Re: [time-nuts] WWVB Dephaser Question

M, John C. Westmoreland, P.E. > wrote: > > Bob, > > Thanks for the answer; but does anyone actually have a documented > specification posted for one of these 'massive' WWVB 60kHz antennas > someplace? > > Thanks. > > 73's, > John > AJ6BC > > &

Re: [time-nuts] WWVB Dephaser Question

ata > for my CPU to process and send to a display. > > I already have a GPS based clock that I built so I thought the WWVB > phase clock would be an interesting project. > > Ray > > Original Message ---- > Subject: Re: [time-nuts] WWVB Dephaser Qu

Re: [time-nuts] WWVB Dephaser Question

time-nuts group. >> As they say have fun. >> Regards >> Paul. >> WB8TSL >> >> On Thu, Oct 8, 2020 at 5:39 PM wrote: >> >>> Bob, >>> >>> I am using a ferrite rod antenna for the receiver. No outside antenna. >>>

Re: [time-nuts] What's available in the way of DSP for new WWVB?

Hi For a full setup, you could do it a lot of ways. A setup of: Antenna -> front end -> ADC -> MCU -> D/A would be one approach. Various bits like a local clock also would get into the design. There are *many* other approaches. == There are a lot of D/A’s that will clock in the 100’s

Re: [time-nuts] WWVB Dephaser Question

> 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

Re: [time-nuts] WWVB Dephaser Question

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

Re: [time-nuts] Aging 5065A ?

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

Re: [time-nuts] Aging 5065A ?

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 ? >

Re: [time-nuts] Aging 5065A ?

Hi Well….. the existing synth in the 5065 is no champion spur wise. Coming up with a DDS that is “as good as” is not all that crazy. The 5 MHz reference is multiplied to 6.x GHz and then mixed with the synth. The close in phase noise of the multiplied signal is mixed with the synth. The

Re: [time-nuts] Aging 5065A ?

he length of the accumulator. What about the D/A > then? 73 - Mike > > Mike B. Feher, N4FS > 89 Arnold Blvd. > Howell NJ 07731 > 848-245-9115 > > -Original Message- > From: time-nuts On Behalf Of Bob kb8tq > Sent: Wednesday, October 7, 2020 1:55 PM > To: Discussion

Re: [time-nuts] Experiment in lowering the TAPR TICC noise floor

Hi > On Oct 7, 2020, at 4:25 PM, John Ackermann N8UR wrote: > > Hi Attila -- > > Just a couple of corrections -- the "coarse clock" in the TICC runs at 10 kHz > (100 us), not 1 kHz, and therefore the TDC never sees a measurement interval > longer than 100 us, not 1 ms. > > More importantly,

Re: [time-nuts] Aging 5065A ?

S > 89 Arnold Blvd. > Howell NJ 07731 > 848-245-9115 > > -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

Re: [time-nuts] Aging 5065A ?

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

Re: [time-nuts] Aging 5065A ?

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

Re: [time-nuts] Aging 5065A ?

Hi Replacing the synthesizer with something more modern is certainly possible. I have a project (slowly moving along) to do just that. There is nothing crazy on the logic board, it could easily be replaced with something more modern for not a lot of money. The phase detector / photo amp /

Re: [time-nuts] Spectracom 8161 "Standard Frequency Receiver - Oscillator" for WWVB (and question...)

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

Re: [time-nuts] Spectracom 8161 "Standard Frequency Receiver - Oscillator" for WWVB (and question...)

Hi The height of the ionosphere changes night to day. That changes the effective propagation distance. As the day/night (or night/day) transition point crosses the path between you and WWVB the two “modes” compete with each other. They can do fun stuff like cancel out the signal entirely. If

Re: [time-nuts] Spectracom 8161 "Standard Frequency Receiver - Oscillator" for WWVB (and question...)

> .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 >

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