Re: [time-nuts] WWVB BPSK Receiver Project?

OK,  John Forster and I have been kicking around a few things off line, and he suggested I should bring part of it back on line. Maybe I have a few details wrong, or maybe I have them right and some folks are unaware of them. My concern about the BPSK, and breaking my Spectracom oscillator, is r

Re: [time-nuts] WWVB BPSK Receiver Project?

Looks like this bounced as I sent from the wrong address. Better late than never. On Wed, 14 Mar 2012 15:46:48 -0700, Chuck Forsberg WA7KGX N2469R wrote: > Asus has a $30 Xonar PCI soundcard that should do the job. > I have two of the the more expensive pci-e versions. Some motherboards > can

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

gary schrieb: Just meditating out loud, if you were to go push pull with a ferrite antenna AND you are winding it yourself, you could avoid the biasing resistors by putting a center tap in the antenna itself, then tie that center tap to an appropriate bias voltage. I haven't seen this done, so

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <4f669a4d.3010...@lazygranch.com>, gary writes: >DC in a transformer raises the low frequency corner a bit. Obviously not >a problem in your case. I just double-checked, because that rang a bell. I did reinstate the capacitors as 2.2uF films in the final article for exactly that reas

Re: [time-nuts] WWVB BPSK Receiver Project?

In message <595370411-1332118092-cardhu_decombobulator_blackberry.rim.net-18097 4826-@b1.c24.bise6.blackberry>, shali...@gmail.com writes: >I was not concerned about processing power on a PC (or Mac for >that matter) but for the uC that was used in PHK's project. That was sort of the entire point

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

DC in a transformer raises the low frequency corner a bit. Obviously not a problem in your case. I should point out that every active device Lankford puts in the signal chain adds noise since the amp is really just a buffer, not an amplifier. You really want front end gain so that devices afte

Re: [time-nuts] WWVB BPSK Receiver Project?

Date: Thu, 15 Mar 2012 15:48:41 To: Discussion of precise time and frequency measurement Reply-To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receiver Project? On Thu, Mar 15, 2012 at 3:13 PM, Poul-Henning Kamp wrote: > In

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <20120318182440.7cb729c2b018b0b2ca5f9...@kinali.ch>, Attila Kinali w rites: >On Sun, 18 Mar 2012 13:25:54 + >> Not in my implementation, I have eliminated the input capacitor because >> the active element is 3cm from the PCB, > >Could you explain how the distance of the antenna to t

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

ehydra wrote: I wonder because ALL of the shown circuits in his pdf are AC-coupled. It is maybe possible to servo-loop with OpAmps but surely not worth the effort. Useful too as a Scope FET-probe. Not really the gain inaccuracy is somewhat excessive. One can do much better with the right ci

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

My choice would be a center tapped, shielded, air core loop, running into a low noise instrumentation amp. Center tap of loop to twinax shield, grounded at preamp. The instrumentation amp has fixed gain, and very high CMRR and PSRR. It also does the differential to single ended conversion properl

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

I'd not use a vertical antenna at all. Far too prone to EMI. My choice would be a center tapped, shielded, air core loop, running into a low noise instrumentation amp. Center tap of loop to twinax shield, grounded at preamp. The instrumentation amp has fixed gain, and very high CMRR and PSRR. It

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

The circuit in question doesn't appear to be in the PDF. You need to use a lot of caution with Lankford's theories. I don't want to get into a pissing contest, so I will leave it at that. Push pull with transformers goes back to the tube days. It is a convenient scheme to kill 2nd harmonic dis

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Sun, 18 Mar 2012 13:25:54 + "Poul-Henning Kamp" wrote: > In message <4f65d971.8070...@arcor.de>, ehydra writes: > > >http://home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf > > > In my implementation, it covered DC to 200MHz until I low-pass'ed it. > > > >His desi

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

I wonder because ALL of the shown circuits in his pdf are AC-coupled. It is maybe possible to servo-loop with OpAmps but surely not worth the effort. Useful too as a Scope FET-probe. - Henry Poul-Henning Kamp schrieb: > In message <4f65d971.8070...@arcor.de>, ehydra writes: > >> http://hom

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <4f65d971.8070...@arcor.de>, ehydra writes: >http://home.earthlink.net/~christrask/Complementary%20Push-Pull%20Amplifiers.pdf > > In my implementation, it covered DC to 200MHz until I low-pass'ed it. > >His designs are always a good source but this one is AC-coupled ;-) Not in my imple

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Poul-Henning Kamp schrieb: > In message <4f64f279.4040...@arcor.de>, ehydra writes: >> Marek Peca schrieb: > >>> This was almost the only reason for ferrite rod -- simplicity and >>> attenuation of TVs, some LCDs, 50Hz etc. >> If you make the antenna about 10x bigger you can omit the whole ferr

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <4f64f279.4040...@arcor.de>, ehydra writes: >Marek Peca schrieb: >> This was almost the only reason for ferrite rod -- simplicity and >> attenuation of TVs, some LCDs, 50Hz etc. > >If you make the antenna about 10x bigger you can omit the whole ferrite. I have used two antennas, an u

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

No, there is a geometric saturation. You can't use the better permeability in reality. The optimum length to width relation is about 6 to 10 for ferrite rods. Here is a diagram: http://ehydra.dyndns.info/NG/time-nuts/Pettengill%20002.jpg This is one of the classics in my link list: http://www.b

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

e: [time-nuts] WWVB BPSK Receiver Project? (fwd) Marek Peca schrieb: This was almost the only reason for ferrite rod -- simplicity and attenuation of TVs, some LCDs, 50Hz etc. If you make the antenna about 10x bigger you can omit the whole ferrite. The only benefit of a ferrite loaded coil is the

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In the end every antenna receives the EM wave! The EM-wave is the far field. The antenna works in the near field where a dominant component can be the E or M. That depends on the antenna. Between the near and the far field the field is "converted" and local Z0 highly complicated. As far as I know

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Peca; Discussion of precise time and frequency measurement Reply-To: ehy...@arcor.de, Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receiver Project? (fwd) Marek Peca schrieb: > This was almost the only reason for ferrite rod -- simplicity and >

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

iscussion of precise time and frequency measurement Reply-To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receiver Project? (fwd) gary wrote: >OK, assuming type 61, it is 0.1%/deg C. IME, Type 78 is the usual choice for resonant antennas be

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Marek Peca schrieb: This was almost the only reason for ferrite rod -- simplicity and attenuation of TVs, some LCDs, 50Hz etc. If you make the antenna about 10x bigger you can omit the whole ferrite. The only benefit of a ferrite loaded coil is the size of it! In ancient time radios had flat a

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

gary wrote: OK, assuming type 61, it is 0.1%/deg C. IME, Type 78 is the usual choice for resonant antennas below 200 kHz (tempco of initial permeability = 1.0%/deg C). I have seen Type 33 used for broadband LF/MF antennas (tempco of initial permeability = 0.1%/deg C). Type 61 is generally

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

-boun...@febo.com Date: Sat, 17 Mar 2012 16:10:48 To: Discussion of precise time and frequency measurement Reply-To: ehy...@arcor.de, Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receiver Project? (fwd) Hi Marek - I don't know where you are in CZ.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Dear Henry, I don't know where you are in CZ. I'm on the boarder in DE near PL and CZ. my former measurement (the one at YouTube, fairly good reception, winter) has been done under Erzgebirge, Teplice, CZ. Now I moved near Sumava (Boehmischer Wald), so tests may follow, if I will return to t

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Hi Marek - I don't know where you are in CZ. I'm on the boarder in DE near PL and CZ. The distance to DCF77 is about 450km and if I check the amplitude across 24h I see considerable very deep fading effects! I think it is useless as a phase-coupled time receiver. At least in specific position

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

http://www.fair-rite.com/newfair/materials61.htm OK, assuming type 61, it is 0.1%/deg C. Let's go with +/- 5 degrees, which would be for indoor use. I don't have the equation handy for a damped LC. Certainly undamped would be worst case. f=1/(2*pi*sqrt(LC)). When the dust settles, the freque

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

That would be 36ns group delay variation if I did the math correctly. OK And in article P. Hetzel: Time dissemination via the LF transmitter DCF77 using a pseudo-random phase-shift keying of the carrier, 2nd EFTF Neuchatel, 1988., they conclude with timing results of about 2..10e-6 s RMS ove

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

That would be 36ns group delay variation if I did the math correctly. However, what material are you using for the ferrite? The material can have a significant tempco. On 3/17/2012 7:17 AM, Marek Peca wrote: However, for f0=77.5kHz and B=1kHz, the LC circuit with Q=40 gives phase error over

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

I think the tempco of the ferrite is more significant than drift in the analog filter. Perhaps I was unclear in this as well. I do not use nor plan to use any other filter than the (ferrite-L)-C resonant circuit itself. So, yes, the tempco of the ferrite makes its coefficients variation. The

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

I think the tempco of the ferrite is more significant than drift in the analog filter. Of course this again implies the better design is to not load the inductor with a cap, i.e. stay broadband, and then just filter post the preamp. The open circuit voltage will be lower without the resonant c

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Yes, in order to equalize group delay, you need to know what to equalize. But with an educated guess as to the system response, he could get close. All this said, in 2012, I would rather the amplifier be simple gain, the inductor not loaded with capacitance and the filtering done past the ampl

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Hi The problem with delay compensation in a Time Nut environment is that to do it you add delay. Your all pass network adds enough delay to the "fast" part of the passband to make it come out the same as the slow part. In real circuits you inevitably add some delay everywhere with the all pass,

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Which basically matched my assumption. If the inductor is loaded, you have a narrowband filter. So again, this does not imply that a ferrite rod antenna per se has phase distortion. It is the LC filter than effects the group delay. Yes, exactly. Excuse my loose speech before not explicitly men

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Yes, in order to equalize group delay, you need to know what to equalize. But with an educated guess as to the system response, he could get close. All this said, in 2012, I would rather the amplifier be simple gain, the inductor not loaded with capacitance and the filtering done past the amp

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Which basically matched my assumption. If the inductor is loaded, you have a narrowband filter. So again, this does not imply that a ferrite rod antenna per se has phase distortion. It is the LC filter than effects the group delay. On 3/17/2012 6:19 AM, Marek Peca wrote: Hello, gary, I los

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Any filter's group delay can be equalized by all pass filters. Delay builds up at the filter corner. Since everything in the real world is causal, you add delay outside that corner frequency but in the passband to equalize it. This is to say, you can't remove delay, but just add it to flatten

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

I've designed filters for datacom chips. I know filtering. My point is the original author is making some assumptions in the design which are not stated. Yes, my fault, I didn't write it properly, so by a "ferrite rod" in context of DCF/WWVB reception, I meand a "ferrite antenna in an LC tuned

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Dear Poul-Henning, My only argument against your versatile and well-performing solution is that it is a little bit overkill. As if running a handfull precision oscillators just for fun isn't "overkill" also ? :-) I don't know -- are there any limits for the fun in a time-nut sense? :-) I hop

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Sat, 17 Mar 2012 06:13:28 -0700 gary wrote: > On 3/17/2012 5:44 AM, Attila Kinali wrote: > > On Sat, 17 Mar 2012 10:15:17 + > > "Poul-Henning Kamp" wrote: > > > >> Either you need to characterize the exact behaviour of your filter > >> and build the necessary compensation for its phase/fr

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Hello, gary, I lost track of who wrote this, but why is it assume a ferrite rod has non-linear phase. [Group delay error I presume). Now I assume this presumes the rod is used in a LC circuit, but if the Q is not high, the phase linearity won't necessarily be bad. Basically I'd like to hear

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Any filter's group delay can be equalized by all pass filters. Delay builds up at the filter corner. Since everything in the real world is causal, you add delay outside that corner frequency but in the passband to equalize it. This is to say, you can't remove delay, but just add it to flatten

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Sat, 17 Mar 2012 10:15:17 + "Poul-Henning Kamp" wrote: > Either you need to characterize the exact behaviour of your filter > and build the necessary compensation for its phase/frequency behaviour > into your receiver, or you need a very flat filter (both freq+phase) > in order to reliably

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Sat, 17 Mar 2012 10:27:03 + li...@lazygranch.com wrote: > What I don't have a lot of hands on experience is with open circuit > magnetics. (I do with closed circuit magnetics.) But I claim if the > ferrite rod antenna is not capacitively loaded to resonate at the > comm frequency, then ther

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Sat, 17 Mar 2012 10:15:17 + "Poul-Henning Kamp" wrote: > In message <2012031719.9536107ebf82050fe14ee...@kinali.ch>, Attila Kinali > w > rites: > >On Sat, 17 Mar 2012 10:01:13 + > > >Could you explain why? Yes, you need a higher BW for Loran-C, > >but the phase(f) function will g

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

12 10:47:23 To: Discussion of precise time and frequency measurement Reply-To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receiver Project? (fwd) On Fri, 16 Mar 2012 20:02:27 -0700 gary wrote: > I lost track of who wrote this, but why is it assume

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <2012031719.9536107ebf82050fe14ee...@kinali.ch>, Attila Kinali w rites: >On Sat, 17 Mar 2012 10:01:13 + >Could you explain why? Yes, you need a higher BW for Loran-C, >but the phase(f) function will give you only a distortion of >the signal and a constant time delay in your sign

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Sat, 17 Mar 2012 10:01:13 + "Poul-Henning Kamp" wrote: > >That said, i think this can be ignored for all practical purposes > >in an VLF receiver, as the enviromental changes in the atmospheric > >signal path are much larger than the small error you get from the > >filter. But then again,

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <20120317104723.8c1832454f14a3f91a4fb...@kinali.ch>, Attila Kinali w rites: >That said, i think this can be ignored for all practical purposes >in an VLF receiver, as the enviromental changes in the atmospheric >signal path are much larger than the small error you get from the >filter.

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Fri, 16 Mar 2012 20:02:27 -0700 gary wrote: > I lost track of who wrote this, but why is it assume a ferrite rod has > non-linear phase. [Group delay error I presume). Now I assume this > presumes the rod is used in a LC circuit, but if the Q is not high, the > phase linearity won't necessa

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Moin! On Fri, 16 Mar 2012 13:45:04 + "Poul-Henning Kamp" wrote: > >Hmm.. i someday have to look for a good introdcution into this stuff > >that doesn't rely on a lot of math. All the books i have rely at least > >on Laplace.. often on z-transformation as well. And that math isn't > >high sc

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message , Marek Peca writes: >My only argument against your versatile and well-performing solution is >that it is a little bit overkill. As if running a handfull precision oscillators just for fun isn't "overkill" also ? :-) >In other words, it would be certainly better to buy USRP N210, Ac

Re: [time-nuts] WWVB BPSK Receiver Project?

So, I just recently started trying to resurrect a Spectracom 8160A reference oscillator. I'm assuming this is proposed WWVB change going to bite me in the butt on this project as well. Not sure how it differs from units like the HP 117, but my understanding is that most of the old VLF receivers

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

I lost track of who wrote this, but why is it assume a ferrite rod has non-linear phase. [Group delay error I presume). Now I assume this presumes the rod is used in a LC circuit, but if the Q is not high, the phase linearity won't necessarily be bad. Basically I'd like to hear more from whome

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Hello, thank you for your oppinion. On Thu, 15 Mar 2012, Poul-Henning Kamp wrote: In message , Marek Peca writes: Yes, it should work on any USB audio capable OS, ie. Linux, Windows, MacOS etc. I would like to recommend against this approach for a number of reasons. First, yes, while you

Re: [time-nuts] WWVB BPSK Receiver Project?

On 14 Mar, 2012, at 18:08 , Brooke Clarke wrote: > The WWB paper "New Improved System for WWVB Broadcast" given at the 43rd PTTI > November 2011 is at: http://jks.com/wwvb.pdf > > Part of the processing gain comes directly from the BPSK modulation and that > amounts to a little over 10 dB impr

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

...@febo.com] On Behalf Of Tom Van Baak Sent: Friday, March 16, 2012 12:59 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receiver Project? (fwd) Bob, To address that diurnal phase issue, for fun, we could set up a cloud-based time-nuts WWVB common view

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Bob, To address that diurnal phase issue, for fun, we could set up a cloud-based time-nuts WWVB common view network. With a couple of sites in each state, imagine the wonderful daily or hourly animated plots that would result. /tvb Hi My main concern on short averages is the relatively long p

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message , "Bob Camp" writes: >My main concern on short averages is the relatively long path from WWVB to >most of the target audience. The day / night phase shift is fairly >significant over a long path. So do I relative to DCF77 which I used for my experiments. The point about having 8 buffe

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

feed into the signal estimation side of the process. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Friday, March 16, 2012 12:27 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <34c510bb3c6449b89ac4f7fbc20f4...@vectron.com>, "Bob Camp" writes: >One assumption is that you will indeed be capturing / averaging for several >days. I'd include some sort of model for sunrise / sunset shifts (might be >just "ignore for the next hour"). Some of my best results had 8

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

ake a multi day average meaningful. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Friday, March 16, 2012 9:03 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receive

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <20120316141539.d8305feaa33c99781667e...@kinali.ch>, Attila Kinali w rites: >Hmm.. i someday have to look for a good introdcution into this stuff >that doesn't rely on a lot of math. All the books i have rely at least >on Laplace.. often on z-transformation as well. And that math isn't

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Fri, 16 Mar 2012 03:08:47 -0700 Hal Murray wrote: > > p...@phk.freebsd.dk said: > >> Hmm... do you mean you want to store all samples of an hour and then > >> avarage over it? > > > That would be the ideal way to do it, since it would make one heck of a comb > > filter and eliminate pretty m

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message , "Bob Camp" writes: >Could you generate a "lead" and a "lag" estimate of the signal (in addition >to your "center") and integrate against each of them on the fly? If so you >would need a *lot* less memory. I seem to recall you tried something like >this on the one of the Loran receiver

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Poul-Henning Kamp Sent: Friday, March 16, 2012 4:23 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Recei

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

p...@phk.freebsd.dk said: >> Hmm... do you mean you want to store all samples of an hour and then >> avarage over it? > That would be the ideal way to do it, since it would make one heck of a comb > filter and eliminate pretty much anything else. That only works if your reference clock is stabl

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <20120316085256.9e25deaeee4f7f8617989...@kinali.ch>, Attila Kinali w rites: >Hmm... do you mean you want to store all samples of an hour and then >avarage over it? That would be the ideal way to do it, since it would make one heck of a comb filter and eliminate pretty much anything els

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Moin! On Fri, 16 Mar 2012 07:09:05 + "Poul-Henning Kamp" wrote: > In message <20120315234624.a2da94430a247d235ca68...@kinali.ch>, Attila Kinali > writes: > >On the other hand, if you dont have to support an OS and work on the > >bare metal, you can get away with very little RAM. 128k is a

Re: [time-nuts] WWVB BPSK Receiver Project?

In message , Chris Albertson writes: >But you are right in that using dttsp [...] GNU Radio If the objective here is time-nuttery, both of these are badly suited because they are built to extract the rapidly changing information, not for long averages of carrier phase. -- Poul-Henning Kamp

Re: [time-nuts] WWVB BPSK Receiver Project?

In message , Chris Albertson writes: >That would be big expensive filter. All you really need is the >average of the last N samples. Expensive ? 2kB of memory ? Not even close to expensive. > But with a 24b-t ADC you may not need AGC 16 bits has meant that I never needed AGC. -- Poul-Hen

Re: [time-nuts] WWVB BPSK Receiver Project?

In message , Azelio Boriani writes: >I'm interested in your circular averaging buffer: suppose 1K long, the 1st >sample goes into position 0, the 2nd into 1 ... the 1000th into 999 or, the >1st gets scaled and then summed with that already present in position 0 >then the result back in position

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message <20120315234624.a2da94430a247d235ca68...@kinali.ch>, Attila Kinali w rites: >How good would that DAC need to be? Depends on the level of ambition ? >> 1-4MB RAM > >over a 256kB RAM it's get pretty thin if you want to stay in the uC >busines. Unless you want to use an ARM9 or better wi

Re: [time-nuts] WWVB BPSK Receiver Project?

Frankly, my dear, I'd rather be a generalist. -John > On 3/15/12 8:10 AM, J. Forster wrote: >> Why make it simple when complicated also works? >> >> -John > > Can't get your doctorate doing something someone else has already > done... >> > >>> >>> Enormous literature out there on th

Re: [time-nuts] WWVB BPSK Receiver Project?

On 3/15/12 9:41 PM, Chris Albertson wrote: On Thu, Mar 15, 2012 at 8:45 PM, Jim Lux wrote: http://dttsp.sourceforge.net/ documentation for dttsp is less than wonderful http://www.oz9aec.net/index.**php/gnu-radio/grc-examples

Re: [time-nuts] WWVB BPSK Receiver Project?

On Thu, Mar 15, 2012 at 8:45 PM, Jim Lux wrote: > >> http://dttsp.sourceforge.net/ >> > > documentation for dttsp is less than wonderful > > > http://www.oz9aec.net/index.**php/gnu-radio/grc-examples >> > > seems to be a bit more diverse u

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On 3/15/12 3:27 PM, Poul-Henning Kamp wrote: In message, Marek Peca writes: Yes, it should work on any USB audio capable OS, ie. Linux, Windows, MacOS etc. I would like to recommend against this approach for a number of reasons. First, yes, while you can do undersampling and such, it puts v

Re: [time-nuts] WWVB BPSK Receiver Project?

On 3/15/12 3:24 PM, Chris Albertson wrote: On Thu, Mar 15, 2012 at 2:51 PM, Attila Kinali wrote: After the discussion here, i had a similar idea. I want to use the STM32F4xx for something bigger and bought two discovery boards to get used to them. But i didn't know what i want to do... it shou

Re: [time-nuts] WWVB BPSK Receiver Project?

On 3/15/12 8:10 AM, J. Forster wrote: Why make it simple when complicated also works? -John Can't get your doctorate doing something someone else has already done... Enormous literature out there on this, and it's been grist for many a Master's or PhD dissertation. All in a quest to get

Re: [time-nuts] WWVB BPSK Receiver Project?

That would be big expensive filter. All you really need is the average of the last N samples. But with WWVB the bits are amplitude modulated at one bit per second. so you want a big time constant on any AGC, maybe 100 seconds. If you are sampling at 192K that would use way to much memory if you

Re: [time-nuts] WWVB BPSK Receiver Project?

PHK, I'm interested in your circular averaging buffer: suppose 1K long, the 1st sample goes into position 0, the 2nd into 1 ... the 1000th into 999 or, the 1st gets scaled and then summed with that already present in position 0 then the result back in position 0? And so on, of course, for position

Re: [time-nuts] WWVB BPSK Receiver Project?

On Thu, Mar 15, 2012 at 3:13 PM, Poul-Henning Kamp wrote: > In message <20120315152620.8347488e049854218aed4...@kinali.ch>, Attila Kinali > w > rites: > >>> Do you need 16 bits or can you get by with a 12 bit ADC? > > In general: The more the merrier, for a digital dude like me, having > more bit

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

On Thu, 15 Mar 2012 22:27:53 + "Poul-Henning Kamp" wrote: > If I, based on my design, were to design a gadget for doing VLF > time-nuts stuff, it would be: > > Floating Input trafo with center-tap for powering antenna > 16 bit 1MSPS ADC > ARM chip > 10MHz clock input > 1PPS sync input > 1PP

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

In message , Marek Peca writes: >Yes, it should work on any USB audio capable OS, ie. Linux, Windows, MacOS etc. I would like to recommend against this approach for a number of reasons. First, yes, while you can do undersampling and such, it puts very high requirements on your analog filters.

Re: [time-nuts] WWVB BPSK Receiver Project?

On Thu, Mar 15, 2012 at 2:51 PM, Attila Kinali wrote: > After the discussion here, i had a similar idea. I want to use the > STM32F4xx for something bigger and bought two discovery boards to get > used to them. But i didn't know what i want to do... it should be something > usefull.. at least hal

Re: [time-nuts] WWVB BPSK Receiver Project?

In message <20120315152620.8347488e049854218aed4...@kinali.ch>, Attila Kinali w rites: >> Do you need 16 bits or can you get by with a 12 bit ADC? In general: The more the merrier, for a digital dude like me, having more bits is easier than getting AGC working correctly :-) >> Have you consider

Re: [time-nuts] WWVB BPSK Receiver Project?

On Thu, 15 Mar 2012 22:51:55 +0100 Attila Kinali wrote: > > Of course I mean it should pick your 60kHz, as well as other systems known > > to > > me: Japanese 40kHz, 60kHz, Swiss 75kHz, British 60kHz and possibly others. > > Highly unsure about Russian 25kHz, even do not know, whether it is st

Re: [time-nuts] WWVB BPSK Receiver Project?

On Thu, 15 Mar 2012 20:02:31 +0100 (CET) Marek Peca wrote: > Of course I mean it should pick your 60kHz, as well as other systems known to > me: Japanese 40kHz, 60kHz, Swiss 75kHz, British 60kHz and possibly others. > Highly unsure about Russian 25kHz, even do not know, whether it is still on

Re: [time-nuts] WWVB BPSK Receiver Project?

The major advantage of simply sampling at 192K is that it is so simple. Not much hardware outside of a good audio interface is required. But the mixer is attractive because then you can make it a quadrature mixer and then sample with both stereo channels. One then could use a more common 44.1

Re: [time-nuts] WWVB BPSK Receiver Project?

On Thu, Mar 15, 2012 at 1:48 AM, Chuck Forsberg WA7KGX N2469R wrote: > How about this:  Generate a precise 60 KHz signal from a GPSDO's 10 MHz. > Modulate it with 1 bit audio generated by a Linux program which would know > about DST. The standard NTP source code distribution comes with a program

Re: [time-nuts] WWVB BPSK Receiver Project? (fwd)

Forgot to Cc: the maillist, sorry. So, FYI: -- Forwarded message -- Date: Thu, 15 Mar 2012 16:31:14 +0100 (CET) From: Marek Peca To: David J Taylor Subject: Re: [time-nuts] WWVB BPSK Receiver Project? Hello, I would perhaps be interested in something which would pick up our

Re: [time-nuts] WWVB BPSK Receiver Project?

0:26 AM To: shali...@gmail.com; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] WWVB BPSK Receiver Project? On Thu, 15 Mar 2012 13:50:08 + shali...@gmail.com wrote: > Poul-Henning, > > Do you need 16 bits or can you get by with a 12 bit ADC? > > Hav

Re: [time-nuts] WWVB BPSK Receiver Project?

On Thu, 15 Mar 2012 07:49:15 -0700 (PDT) "J. Forster" wrote: > Suppose the modulation is not present. The output of the phase detector > that steers the local standard ot indicator works correctly. > > Now reverse the 60 kHz carrier. The phase detector works exactly thye > opposite way... wrong

Re: [time-nuts] WWVB BPSK Receiver Project?

Why make it simple when complicated also works? -John > On 3/15/12 7:49 AM, J. Forster wrote: >> Suppose the modulation is not present. The output of the phase detector >> that steers the local standard ot indicator works correctly. >> >> Now reverse the 60 kHz carrier. The phase

Re: [time-nuts] WWVB BPSK Receiver Project?

On 3/15/12 7:49 AM, J. Forster wrote: Suppose the modulation is not present. The output of the phase detector that steers the local standard ot indicator works correctly. Now reverse the 60 kHz carrier. The phase detector works exactly thye opposite way... wrong. Now alternate between 0 and 19

Re: [time-nuts] WWVB BPSK Receiver Project?

Jim wrote: a square wave, >> multiplied by itself, has the same output as input. > > Oh... I was assuming you had the two quadrature square waves (which are > just like the saturated LO for the mixer in RF land) You don't have two square waves in quadrature. You have the (amplified) signal from t

Re: [time-nuts] WWVB BPSK Receiver Project?

Suppose the modulation is not present. The output of the phase detector that steers the local standard ot indicator works correctly. Now reverse the 60 kHz carrier. The phase detector works exactly thye opposite way... wrong. Now alternate between 0 and 190 degrees. The loop alternate works bet

Re: [time-nuts] WWVB BPSK Receiver Project?

There are a number of sound cards (and have been for 10 years now) that can capture up to 95 KHz with extraordinary fidelity. They sample at 192 KHz and usually have "24" bit converters good tor 20+ bits. These can capture the complete FM MPX output pretty easily. Some of the newer ADC's have less

Re: [time-nuts] WWVB BPSK Receiver Project?

Dear american colleagues, as I read last few posts about WWVB, I am very tempted to return to LF time signal fun. As I wrote you, there vere very good results using cheap 2 IC circuitry and a PC with our local DCF77 signal. Under influence of this maillist, I am thinking about recreating of t

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