Hi gang,
There seem to be a lot of surplus GPS discliplined 10MHz OCXOs on eBay
lately.
Anyone here have experience using a setup like that?
I'm still looking into getting my lab equipped, I'm looking into the
frequency thing.
Besides GPS, there's the national standards.
The Canadian equivalent to WWV is CHU, they broadcast time signals on
a few frequencies.
Has anyone tried disciplining an OCXO to the carrier of these signals?
The carrier is derived from an atomic clock, but atmospherics probably
mean I'd have to average over a few days to get ~10-11 accuracy.
I'm not finding a lot of information about CHU setups. I'm guessing a
dipole in the backyard, some gain, and that's it?

a...@netzero.com wrote:
> Hi gang,
> There seem to be a lot of surplus GPS discliplined 10MHz OCXOs on eBay
> lately.
> Anyone here have experience using a setup like that?
> I'm still looking into getting my lab equipped, I'm looking into the
> frequency thing.
> Besides GPS, there's the national standards.
> The Canadian equivalent to WWV is CHU, they broadcast time signals on
> a few frequencies.
> Has anyone tried disciplining an OCXO to the carrier of these signals?
> The carrier is derived from an atomic clock, but atmospherics probably
> mean I'd have to average over a few days to get ~10-11 accuracy.
> I'm not finding a lot of information about CHU setups. I'm guessing a
> dipole in the backyard, some gain, and that's it?

The usual method is to use WWVB at 60 kHz, with a ferrite loopstick 
antenna, a crystal filter, and a PLL.  You can get nice 2400 mu ferrite 
from Amidon.   The ground wave delay is more stable than the sky wave 
from the 10 MHz stations.

Cheers

Phil Hobbs

-- 
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

On Oct 24, 1:56 pm, Phil Hobbs
<pcdhSpamMeSensel...@electrooptical.net> wrote:
>
> The usual method is to use WWVB at 60 kHz, with a ferrite loopstick
> antenna, a crystal filter, and a PLL.  You can get nice 2400 mu ferrite
> from Amidon.   The ground wave delay is more stable than the sky wave
> from the 10 MHz stations.
>

I see, thanks.

On Sat, 24 Oct 2009 14:56:36 -0400, Phil Hobbs
<p...@electrooptical.net> wrote:

>a...@netzero.com wrote:
>> Hi gang,
>> There seem to be a lot of surplus GPS discliplined 10MHz OCXOs on eBay
>> lately.
>> Anyone here have experience using a setup like that?
>> I'm still looking into getting my lab equipped, I'm looking into the
>> frequency thing.
>> Besides GPS, there's the national standards.
>> The Canadian equivalent to WWV is CHU, they broadcast time signals on
>> a few frequencies.
>> Has anyone tried disciplining an OCXO to the carrier of these signals?
>> The carrier is derived from an atomic clock, but atmospherics probably
>> mean I'd have to average over a few days to get ~10-11 accuracy.
>> I'm not finding a lot of information about CHU setups. I'm guessing a
>> dipole in the backyard, some gain, and that's it?
>
>The usual method is to use WWVB at 60 kHz, with a ferrite loopstick 
>antenna, a crystal filter, and a PLL.  You can get nice 2400 mu ferrite 
>from Amidon.   The ground wave delay is more stable than the sky wave 
>from the 10 MHz stations.
>
>Cheers

Isn't that a once per minute thing?  Perhaps combine the OCXO to
provide interim precision, tethered to and recalibrated for accuracy
periodically by WWVB?  Could also make knowing when to wake up for
receiving WWVB precise, as well.

Odd thing is, I'm wearing a Casio WR50M that does close to this and I
paid a grand total of $14 for it, including the watch band, case,
display, etc.  Too bad that isn't made into a nice, convenient
embedded module.

Jon

a...@netzero.com wrote:
> Hi gang,
> There seem to be a lot of surplus GPS discliplined 10MHz OCXOs on eBay
> lately.
> Anyone here have experience using a setup like that?
> I'm still looking into getting my lab equipped, I'm looking into the
> frequency thing.
> Besides GPS, there's the national standards.
> The Canadian equivalent to WWV is CHU, they broadcast time signals on
> a few frequencies.
> Has anyone tried disciplining an OCXO to the carrier of these signals?
> The carrier is derived from an atomic clock, but atmospherics probably
> mean I'd have to average over a few days to get ~10-11 accuracy.
> I'm not finding a lot of information about CHU setups. I'm guessing a
> dipole in the backyard, some gain, and that's it?


I'm in the uk, but bought one of the telco surplus HP Z3816A ones from 
Ebay US around 5 years ago and been powered up ever since. The Hp active 
antenna came from an Ebay vendor in Korea. They were very expensive in 
the uk at the time. There's a similar unit (58114A ?) in a fancy box and 
expensive, but these are the half rack width x ~4" high industrial 
finish types with a single huge toggle power switch + leds on the front 
panel and rf + serial interfaces on the rear panel. Mine is line input, 
but they come in 48v dc input as well.

There's a utility that talks to the box, which you drive through a 
serial line from a dos shell. This allows you to get status reports and 
set up / compensate things like the nS delay from the antenna cable 
length. It has a couple of 10Mhz sma outputs into 50r, (which drive all 
the counters and synthesisers in the lab) and another odd ball frequency 
which I don't remember.

Stability wise, they can be a bit noisy in the short term, depending on 
the actual unit that you get. Long term of course, they are locked to 
Caesium standards. Certainly good enough for any work done here.

I have the utility on the server if you can't find the download, though 
it's been some time since I hooked a terminal to mine. It just works...

Regards,

Chris

Phil Hobbs <p...@electrooptical.net> wrote in 
news:6...@supernews.com:

> a...@netzero.com wrote:
>> Hi gang,
>> There seem to be a lot of surplus GPS discliplined 10MHz OCXOs on eBay
>> lately.
>> Anyone here have experience using a setup like that?
>> I'm still looking into getting my lab equipped, I'm looking into the
>> frequency thing.
>> Besides GPS, there's the national standards.
>> The Canadian equivalent to WWV is CHU, they broadcast time signals on
>> a few frequencies.
>> Has anyone tried disciplining an OCXO to the carrier of these signals?
>> The carrier is derived from an atomic clock, but atmospherics probably
>> mean I'd have to average over a few days to get ~10-11 accuracy.
>> I'm not finding a lot of information about CHU setups. I'm guessing a
>> dipole in the backyard, some gain, and that's it?
> 
> The usual method is to use WWVB at 60 kHz, with a ferrite loopstick 
> antenna, a crystal filter, and a PLL.  You can get nice 2400 mu ferrite 
> from Amidon.   The ground wave delay is more stable than the sky wave 
> from the 10 MHz stations.
> 
> Cheers
> 
> Phil Hobbs
> 

I'm surprised there isn't some receiver IC that would do this job,and maybe 
a companion IC to do the PLL/dividing.

-- 
Jim Yanik
jyanik
at
localnet
dot com

in the late 1980s there was a plan published in radio electronics that
took a radio shack "time cube" receiver and mixed some signals back
with it to lock a reference.

These days its easier to find a used Jupiter GPS or Trimble
Thunderbolt and make a standard. I just bought a ex cell site rubidium
system for 70$ a few months ago. Just add 24V at 4 amps per warmup and
1.7 amps for run.


http://www.google.com/url?q=http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm&ei=qo_jSrSXOoHWlAfh4OCKBw&a
mp;sa=X&oi=spellmeleon_result&resnum=2&ct=result&ved=0CA8QhgIwAQ&usg=AFQjCNET__pFKRVLxEX3rcML-J7TFTP
V6A

The 10 mhz vcxo was 6$ on ebay.

Steve

Oh and if you cant find a jupiter, (there are none on ebay right now)
let me know,by posting here,  I have a few spares.

Steve

On Sat, 24 Oct 2009 17:48:24 -0500, Jim Yanik <j...@abuse.gov>
wrote:

>Phil Hobbs <p...@electrooptical.net> wrote in 
>news:6...@supernews.com:
>
>> a...@netzero.com wrote:
>>> Hi gang,
>>> There seem to be a lot of surplus GPS discliplined 10MHz OCXOs on eBay
>>> lately.
>>> Anyone here have experience using a setup like that?
>>> I'm still looking into getting my lab equipped, I'm looking into the
>>> frequency thing.
>>> Besides GPS, there's the national standards.
>>> The Canadian equivalent to WWV is CHU, they broadcast time signals on
>>> a few frequencies.
>>> Has anyone tried disciplining an OCXO to the carrier of these signals?
>>> The carrier is derived from an atomic clock, but atmospherics probably
>>> mean I'd have to average over a few days to get ~10-11 accuracy.
>>> I'm not finding a lot of information about CHU setups. I'm guessing a
>>> dipole in the backyard, some gain, and that's it?
>> 
>> The usual method is to use WWVB at 60 kHz, with a ferrite loopstick 
>> antenna, a crystal filter, and a PLL.  You can get nice 2400 mu ferrite 
>> from Amidon.   The ground wave delay is more stable than the sky wave 
>> from the 10 MHz stations.
>> 
>> Cheers
>> 
>> Phil Hobbs
>> 
>
>I'm surprised there isn't some receiver IC that would do this job,and maybe 
>a companion IC to do the PLL/dividing.

There was, then Bowmar went bust...

       http://analog-innovations.com/SED/WWVB-Schematic+Data.pdf
		
                                        ...Jim Thompson
-- 
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
              With Half My Brain Tied Behind My Back
              Still More Clever Than Mr.Prissy Pants

On Sat, 24 Oct 2009 07:38:45 -0700 (PDT), a...@netzero.com
wrote:

>Hi gang,
>There seem to be a lot of surplus GPS discliplined 10MHz OCXOs on eBay
>lately.
>Anyone here have experience using a setup like that?
>I'm still looking into getting my lab equipped, I'm looking into the
>frequency thing.
>Besides GPS, there's the national standards.
>The Canadian equivalent to WWV is CHU, they broadcast time signals on
>a few frequencies.
>Has anyone tried disciplining an OCXO to the carrier of these signals?
>The carrier is derived from an atomic clock, but atmospherics probably
>mean I'd have to average over a few days to get ~10-11 accuracy.
>I'm not finding a lot of information about CHU setups. I'm guessing a
>dipole in the backyard, some gain, and that's it?

Depending on the accuracy you require - and you *did* say hobbyist -
the Jupiter GPSr module is my preferred solution.  I'm allergic to the
loooong conditioning times required by many approaches to
GPS-disciplined arrangements.  A good example of a Jupiter-based setup
(very similar to my own) can be found at

http://www.jrmiller.demon.co.uk/projects/freqstd/frqstd.htm

The benefits of this type of approach are quick settling from cold
start, and low cost oscillator.  Depending on your jitter
requirements, a non-ovened VCXO and a simple loop filter can be more
than satisfactory.  I have checked my own 10MHz Jupiter-based
reference against an ovened TC/VCXO counter timebase and cannot
discern any phase jitter on a CRO or with DC recovery on a NBFM
receiver in a comms test set.

<flame suit on for inevitable purist criticism>