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Discussion of precise time and frequency measurement

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WWV Receivers

HM
Hal Murray
Tue, Feb 7, 2017 7:27 AM

esp. if one uses a Chinese $6.50 incl. shipping HF  receiver off eBay;

Could somebody give me a lesson in receivers appropriate for extracting time
from WWV?

Is $10 a realistic price?

--
These are my opinions.  I hate spam.

> esp. if one uses a Chinese $6.50 incl. shipping HF receiver off eBay; Could somebody give me a lesson in receivers appropriate for extracting time from WWV? Is $10 a realistic price? -- These are my opinions. I hate spam.
PK
Poul-Henning Kamp
Tue, Feb 7, 2017 8:12 AM

esp. if one uses a Chinese $6.50 incl. shipping HF  receiver off eBay;

Could somebody give me a lesson in receivers appropriate for extracting time
from WWV?

Somebody should do an SDR project for this.

Modern microcontrollers have ADC's which are capable of sampling fast
enough and plenty of processing power to demodulate all the parts,
including the phase modulation.

Clock the microcontroller of your house-standard and you have a pretty
good sanity-check on your GPS receivers.

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

-------- In message <20170207072741.B084F406076@ip-64-139-1-69.sjc.megapath.net>, Hal Murray writes: > >> esp. if one uses a Chinese $6.50 incl. shipping HF receiver off eBay; > >Could somebody give me a lesson in receivers appropriate for extracting time >from WWV? Somebody should do an SDR project for this. Modern microcontrollers have ADC's which are capable of sampling fast enough and plenty of processing power to demodulate all the parts, including the phase modulation. Clock the microcontroller of your house-standard and you have a pretty good sanity-check on your GPS receivers. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.
CA
Chris Albertson
Tue, Feb 7, 2017 4:31 PM

On Mon, Feb 6, 2017 at 11:27 PM, Hal Murray hmurray@megapathdsl.net wrote:

esp. if one uses a Chinese $6.50 incl. shipping HF  receiver off eBay;

Could somebody give me a lesson in receivers appropriate for extracting
time
from WWV?

Is $10 a realistic price?

Yes, this would not need to be tunable as WWV is at a fixed frequency.  I
have seen a receiver that uses a 10MHz crystal in the front end and then
mixes the signal to baseband then samples it with a PC "sound card".  $10
in parts easy

You extract the time in the PC software.  I say "PC" but a really low-end
computer like a Rasperry Pi would be perfect for this, maybe over kill but
you'd want the features of the OS to send the time some place

Chris Albertson
Redondo Beach, California

On Mon, Feb 6, 2017 at 11:27 PM, Hal Murray <hmurray@megapathdsl.net> wrote: > > > esp. if one uses a Chinese $6.50 incl. shipping HF receiver off eBay; > > Could somebody give me a lesson in receivers appropriate for extracting > time > from WWV? > > Is $10 a realistic price? > Yes, this would not need to be tunable as WWV is at a fixed frequency. I have seen a receiver that uses a 10MHz crystal in the front end and then mixes the signal to baseband then samples it with a PC "sound card". $10 in parts easy You extract the time in the PC software. I say "PC" but a really low-end computer like a Rasperry Pi would be perfect for this, maybe over kill but you'd want the features of the OS to send the time some place -- Chris Albertson Redondo Beach, California