Timenoob - Cheap and simple 10MHz reference
Hi Sal,
No it does not have a 10MHz output. However to calibrate an oscillator that is very close to 10MHz you can use the 1PPS output to adjust it exactly. Trigger a 'scope with the 1PPS while monitoring the 10MHz, adjust the oscillator for minimum drift across the screen.
Robert.
--- On Mon, 28/12/09, SAL CORNACCHIA salccor@rogers.com wrote:
From: SAL CORNACCHIA salccor@rogers.com
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Monday, 28 December, 2009, 15:32
Hi Robert,
Will the Motorola that You have mentioned give a 10.00 MHz output standard.
Thank You
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Robert Atkinson robert8rpi@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Cc: giuseppe.marullo@iname.com
Sent: Mon, December 28, 2009 5:14:49 AM
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Giuseppe,
Welcome to the group.
If you are already happy constructing equipment and have basic test gear ('scope, DMM) and a small budget, I'd suggest a timing GPS as a starting point. While a Thunderbolt will give most of what you want, it is more expensive. A Timing version or Motorola's Oncore <(ebay item 300355981024 from flukel for instance) will give you an accurate 1 pulse per second output (you also need a power supply antenna and a PC). This and a 'scope will allow you to calibrate other instruments and a oven controlled crystal oscillator. A GPS based solution (including Thunderbolt) will give you good confidence of accuracy. Just buying a surplus Rubidium could result in you adjusting all your instruments to the wrong frequency! Like many of these decisions, it's a balance between time and money, with a lesser input from your capabilities and existing equipment.
Robert G8RPI.
--- On Mon, 28/12/09, Giuseppe Marullo giuseppe@marullo.it wrote:
From: Giuseppe Marullo giuseppe@marullo.it
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Monday, 28 December, 2009, 0:56
Thanks a lot to all for your quick answer.
Rubinium should be good for my needs, but buying it surplus makes me think I could get something very used (and abused) and it does not have the self correcting thing thunderbolt has.
GPSDO gives me also the time, maybe with a supercool LCD display.
A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also needs a GPS antenna of some sort.
Do you know exactly the power requirement? On Ebay I read 15W then few mA on each branch (board only). Something is not clear to me.
The dark side of the noon already embraced I have....
Giuseppe
PS: I am experiencing mail problems for the first time in many years, please anyone willing to contact me directly do cc copy also this other email address: giuseppe.marullo@iname.com while my ISP gathers back all the bits they lost (2 days of emails vanished from my IMAP account under my eyes, literally)
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Giuseppe
Symmetricom made a OXCO that had the DAC built-in so it was controlled by a digital interface. But it is hard to find, seen them on ebay but not now.
Stanley
Thank You Robert for the quick response.
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Robert Atkinson robert8rpi@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Mon, December 28, 2009 12:07:21 PM
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Sal,
No it does not have a 10MHz output. However to calibrate an oscillator that is very close to 10MHz you can use the 1PPS output to adjust it exactly. Trigger a 'scope with the 1PPS while monitoring the 10MHz, adjust the oscillator for minimum drift across the screen.
Robert.
--- On Mon, 28/12/09, SAL CORNACCHIA salccor@rogers.com wrote:
From: SAL CORNACCHIA salccor@rogers.com
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Monday, 28 December, 2009, 15:32
Hi Robert,
Will the Motorola that You have mentioned give a 10.00 MHz output standard.
Thank You
Best regards,
Sal C. Cornacchia
Electronic RF Microwave Engineer (Ret.)
From: Robert Atkinson robert8rpi@yahoo.co.uk
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Cc: giuseppe.marullo@iname.com
Sent: Mon, December 28, 2009 5:14:49 AM
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Hi Giuseppe,
Welcome to the group.
If you are already happy constructing equipment and have basic test gear ('scope, DMM) and a small budget, I'd suggest a timing GPS as a starting point. While a Thunderbolt will give most of what you want, it is more expensive. A Timing version or Motorola's Oncore <(ebay item 300355981024 from flukel for instance) will give you an accurate 1 pulse per second output (you also need a power supply antenna and a PC). This and a 'scope will allow you to calibrate other instruments and a oven controlled crystal oscillator. A GPS based solution (including Thunderbolt) will give you good confidence of accuracy. Just buying a surplus Rubidium could result in you adjusting all your instruments to the wrong frequency! Like many of these decisions, it's a balance between time and money, with a lesser input from your capabilities and existing equipment.
Robert G8RPI.
--- On Mon, 28/12/09, Giuseppe Marullo giuseppe@marullo.it wrote:
From: Giuseppe Marullo giuseppe@marullo.it
Subject: Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
To: "Discussion of precise time and frequency measurement" time-nuts@febo.com
Date: Monday, 28 December, 2009, 0:56
Thanks a lot to all for your quick answer.
Rubinium should be good for my needs, but buying it surplus makes me think I could get something very used (and abused) and it does not have the self correcting thing thunderbolt has.
GPSDO gives me also the time, maybe with a supercool LCD display.
A Thunderbolt needs a triple supply (+12, -12, and +5) to operate. It also needs a GPS antenna of some sort.
Do you know exactly the power requirement? On Ebay I read 15W then few mA on each branch (board only). Something is not clear to me.
The dark side of the noon already embraced I have....
Giuseppe
PS: I am experiencing mail problems for the first time in many years, please anyone willing to contact me directly do cc copy also this other email address: giuseppe.marullo@iname.com while my ISP gathers back all the bits they lost (2 days of emails vanished from my IMAP account under my eyes, literally)
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Giuseppe Marullo wrote:
Robert,
Welcome to the group.
Thank you and all the others, you are giving me a lot of informations.
BTW, my provider retrieved my emails so I am fully operational (at
least I hope).
while I did not originally envision building this kind of equipment, I
could do it while it lies well within the digital domain, I have some
test gear (frequency counter, DMM, analog scope, BF frequency
generator, LA and some FPGAs with 100+Msamples ADC) but...I will have
to trust it so I am back at square one, until I have a reliable
source... I would like a GPSDO, possibly ready to run, then I will
start building something that I could actually check against the GPSDO.
Maybe a GPSDO myself, who knows...wondering if this could be done all
digital, without using a DAC, without using a driving voltage for a OCXO.
Giuseppe
Giuseppe
One can use a DDS or equivalent phase continuous high resolution
sysnthesizer to produce a corrected output frequency using the OCXO
frequency as an input, however the DDS itself uses a DAC and you will
probably need to use a few cascaded mix and divide stages to reduce the
spur amplitude to an acceptable level.
This has the advantage that one can use an OCXO that either doesnt have
an EFC input or one that has drifted beyond the adjustment range (via
EFC and/or mechanical trimmer) but is otherwise quiet and stable.
Bruce