I am wondering if it's a tough road to get precise time and frequency.
How precise do you want? How much money do you have?
1/2 :), but you are asking on the time-nuts list so you should expect answers
like that.
I would love to discipline my counter and signal generator time bases to
One of the simplest ways to receive VLF signals is to buy a surplus
Selective Level Meter.
They were an important piece of test equipment used by the analog
line-line telephony people. Now of course, surplus to requirements.
If you hunt around they can be found at very low prices.
jim...@earthlink.net said:
I sample at 100 kHz with 16 bits on a teensy3..
Neat. Thanks. How many effective bits? (when the input signal is 60 KHz it
that matters)
Can somebody give me a lesson in the tradeoffs between number of bits and
sampling rate?
I know of one special case. If
that is perhaps another 60kHz station they have one in England too!
73
KJ6HN
Alex
On 2/20/2014 8:35 PM, Graeme Zimmer wrote:
I have a Kenwood TS-940S transceiver that can receive 60 kHz but I
have never heard anything
Where are you? It must be deaf as a post.
I can hear WWVB in Australia !
My TS-940S acts as though it receives okay at 60 kHz. Not great sensitivity
but it does receive.
Most HP GPS receivers are expensive ($400?). I was hoping to get some results
with what I have, although I'm willing to cobble up some circuitry.
I assume if I can receive the signal, I can
rich...@karlquist.com said:
I want to use WWVB because I want to be able to mention to visitors that the
clock links to an ensemble of 5071A cesium standards, and I was one of the
designers of the 5071A, the actual atomic clock. ...
Neat.
What does the Air Force use as a reference for GPS?
From: Richard (Rick) Karlquist
Can anyone recommend a atomic wall clock
that displays in digital 24 hour UTC? Looking for largest
possible digits and LED preferred over LCD, under $100.
Any brands to avoid?
Rick
==
Rick, you could make your own with a
R2 is dominated by the adc sample switch on resistance and thus has a
relatively high tempco (~4000ppm/C).
C2 has a relatively low tempco (~100ppm/C or so)
To reduce the effect of the sample switch on resistance tempco on the
gain tempco of the TIC R1 C1 need to be proportioned so that R2 has
Or a discreet receiver using time-nut available stuff. NIST should be the
one that owns the format and they have published it.
Regards
Paul
On Thu, Feb 20, 2014 at 1:45 AM, Richard (Rick) Karlquist
rich...@karlquist.com wrote:
On 2/19/2014 9:10 PM, John Marvin wrote:
I guess my question
Now you've lost me. What 2.5 MHz synchronizer clock? Everything I have
external to the PIC is 10MHz. The PIC is running HSPLL at 40MHz, though I
don't think that makes any difference to this.
Bob
From: Bruce Griffiths bruce.griffi...@xtra.co.nz
To: Bob
Sounds like a great Kickstarter project for some time nuttiers.
On 2/19/2014 9:10 PM, John Marvin wrote:
I guess my question is who has the right to grant exclusive rights for
the ability to decode a very simple protocol? Was a patent actually
granted for this?
John
They have exclusive
Other than WWVB-based frequency references/clocks that lock onto the 60
kHz carrier itself, I'm not aware of any WWVB-based clocks that were the
slightest-bit affected by format change (e.g. the addition of the
low-rate BPSK): Please point me to any references to the contrary if
you find
For a 10MHz synchroniser clock A C1 value of around 220pF or so should
be appropriate.
The exact value depends on the ADC reference voltage.
A n ADC reference less than 5V may be useful.
I'll run some simulations to check the sensitivity to R2's tempco.
Bruce
Bob Stewart wrote:
Now you've
Am Wed, 19 Feb 2014 22:45:56 -0800
schrieb Richard (Rick) Karlquist rich...@karlquist.com:
On 2/19/2014 9:10 PM, John Marvin wrote:
I guess my question is who has the right to grant exclusive
rights for the ability to decode a very simple protocol? Was a
patent actually granted for
Paul Swed posted a working, mostly analog, design here maybe 6 months ago.
-John
=
Am Wed, 19 Feb 2014 22:45:56 -0800
schrieb Richard (Rick) Karlquist rich...@karlquist.com:
On 2/19/2014 9:10 PM, John Marvin wrote:
I guess my question is who has the right to grant exclusive
At 60KHz, it shouldn't be out of range of most
general purpose CPU's, and even the most pathetic DSP.
Why bother with a hardware solution when software can
do it more easily?
-Chuck Harris
Florian Teply wrote:
Well, if someone comes up with a circuit, I could check how much chip
area that
Chuck thats easy. Because I could make it work. :-)
That said there was a post on time-nuts about LORAN C receiver in software.
I responded and have had the great pleasure of communicating with Matthias
over the last two weeks. I have learned a lot already and he in return has
a tested LORAN C
At least on the Atlantic coast, the WWVB signal levels jump all over the
place, certainly 40 dB and maybe more. If a receiver cannot deal w/ that
w/o losing lock, it's nearly useless.
OTOH, LORAN was always a whopping signal.
-John
Chuck thats easy. Because I could make it
Totally agree with you John as I learned. I knew it was a variable but I
have seen nights that were crazy and do fit your 40 db. I redesigned the
AGC to account for that in the fr front end actually.
Regards
Paul
On Thu, Feb 20, 2014 at 4:34 PM, J. Forster j...@quikus.com wrote:
At least on
The large amplitude swings happen on a very short time scale too.
Certainly 1 second at times.
-John
Totally agree with you John as I learned. I knew it was a variable but I
have seen nights that were crazy and do fit your 40 db. I redesigned the
AGC to account for that in the
Hi Paul,
could you give a hint how long ago you released the front end to T_N?
thanks
Neville Michie
(Sydney)
On 21/02/2014, at 8:29 AM, paul swed wrote:
Chuck thats easy. Because I could make it work. :-)
That said there was a post on time-nuts about LORAN C receiver in software.
I
Several years ago I spotted a clever PIC-based software (DSP-ish)
approach to WWVB modulation - but it has thusfar defied my attempts to
find it via Google. It was from the late 90's, early 2000's - and I may
have it in an archive somewhere.
The exact details escape me, but I believe that it
On Thursday, February 20, 2014, J. Forster j...@quikus.com wrote:
The large amplitude swings happen on a very short time scale too.
Certainly 1 second at times.
8-bits is 48 dB. 16-bit parts at 60kHz should be cheap now. Why bother with
AGC? Just make sure the ADC doesn't clip.
Hi
You can get parts in the 18 bit and up range for not a whole lot of money with
rational sample rates for a WWVB receiver. Analog Devices and Linear Tech both
make some interesting looking parts. They get you into the =100 db dynamic
range area.
Even with a lower bit count part, you pick
Clint
I don't know if it was me or not the said the doubling scheme did not work.
It does work but profoundly unreliably at least on the east coast. If you
miss one cycle of carrier you loose phase making it useless. Jfor here on
Time nuts and I tried a lot of things to get around the issues
Hi Paul,
how was that 60kHz RF front end made I was not wit the group six months
ego could you please send me a copy/
thank you in advance
73
KJ6UHN
Alex
On 2/20/2014 1:29 PM, paul swed wrote:
Chuck thats easy. Because I could make it work. :-)
That said there was a post on time-nuts about
Request sent offline.
Regards
Paul
On Thu, Feb 20, 2014 at 9:32 PM, Alex Pummer a...@pcscons.com wrote:
Hi Paul,
how was that 60kHz RF front end made I was not wit the group six months
ego could you please send me a copy/
thank you in advance
73
KJ6UHN
Alex
On 2/20/2014 1:29 PM, paul
Several years ago I spotted a clever PIC-based software (DSP-ish)
approach to WWVB modulation
Perhaps it was mine?
Years ago I designed a PSK31 decoder using a PIC. It worked very well
for fixed frequencies, but I concluded that making it tunable was beyond
the resources of the PICs then
Its still interesting to read an article from Radio-Electronics Magazine
with date stamp back to August 1973. In that article Don Lancaster
explain few classical techniques how to handle WWVB band.
Regards,
V.P.
On 2014-02-20 20:42, Clint Turner wrote:
Several years ago I spotted a clever
I am wondering if it's a tough road to get precise time and frequency.
I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never
heard anything I could guess would be WWVB, just a fair amount of noise. I did
calibrate against 20 MHz WWV so that the beat was one every
I have a Kenwood TS-940S transceiver that can receive 60 kHz but I have never
heard anything
Where are you? It must be deaf as a post.
I can hear WWVB in Australia !
(or at least I could till JJY-60 started in 2001)
... Zim
___
time-nuts
Hi Zim,
With but a very few exceptions most broadband Amateur radfio trancievers
do not do well below 500 KHz even though many allow for tuning below 500
KHz.
BillWB6BNQ
Graeme Zimmer wrote:
I have a Kenwood TS-940S transceiver that can receive 60 kHz but I
have never heard anything
On 2/20/14 4:40 PM, Brian Lloyd wrote:
On Thursday, February 20, 2014, J. Forster j...@quikus.com wrote:
The large amplitude swings happen on a very short time scale too.
Certainly 1 second at times.
8-bits is 48 dB. 16-bit parts at 60kHz should be cheap now. Why bother with
AGC? Just make
I have an OpenHPSDR Hermes and it has no problem receiving WWVB;
however, since I live in Fort Collins - Colorado, part of the success
might just be the strong signal. I wonder if I could just stick a piece
of wire into one of the channel inputs of a 192Khz sample rate audio
interface
I have a wave analyzer which for those who may be unfamiliar with such an
instrument is a super het receiver that tunes from 0 to 50 kHz. Mine has
enough extra range on the high end to hit 60 kHz.I can connect a 40 foot
wire antenna in my attic to its input and receive WWVB here in
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