What's the easiest way to divide by 10 for Thunderbolt reference output?
24/07/2012 13:14
My Racal Dana 9908 can take a 1 Mhz external reference. Inputting my
Thunderbolt at 10 MHz works, but shifts the decimal point over. I am
not sure if this has any other detrimental effects as to accuracy or
other? What's the easiest way to have a 1 MHz reference from the
Thunderbolt for this timer / counter please, yet retaining 10 Mhz for
my other devices that want a 10MHz reference signal? Thanks.
--
Best Regards,
Chris Wilson.
mailto: chris@chriswilson.tv
Ready made or to be built? Use a divide-by-10 (7490-like) set to divide
with 50% duty cycle or divide by 5 then by 2.
On Tue, Jul 24, 2012 at 2:18 PM, Chris Wilson chris@chriswilson.tv wrote:
24/07/2012 13:14
My Racal Dana 9908 can take a 1 Mhz external reference. Inputting my
Thunderbolt at 10 MHz works, but shifts the decimal point over. I am
not sure if this has any other detrimental effects as to accuracy or
other? What's the easiest way to have a 1 MHz reference from the
Thunderbolt for this timer / counter please, yet retaining 10 Mhz for
my other devices that want a 10MHz reference signal? Thanks.
--
Best Regards,
Chris Wilson.
mailto: chris@chriswilson.tv
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.
Ready made or to be built? Use a divide-by-10 (7490-like) set to divide
with 50% duty cycle or divide by 5 then by 2.
Thanks for the reply Azelio.
Sorry, should have said, ready built, got too many half finished jobs
on the go right now. FAR too many according to my wife....
Will be needing some sort of line distribution amplifier soon, been
buying test gear! I believe some people have had good results with TV
aerial distribution amps?
Thanks.
--
Best Regards,
Chris Wilson.
Mine are not handy, so I'm not sure it has 50% output duty, but the Ballantine
6130A Time Mark Generator is a potential candidate. It's not much more than a
chain of 7490 dividers fed from a 10MHz source, and has a (non-nut) ovenized
oscilltor built in. Even has synchronized multipliers that go up to 500MHz. I
couldn't resist buying a 2nd at Dayton this year, cost all of $5 from a dumpster
diver late Sunday. A fair price is more in the $30 - $40 range, which is what I
paid for my first one.
Bob LaJeunesse
From: Chris Wilson chris@chriswilson.tv
To: Discussion of precise time and frequency measurement time-nuts@febo.com
Sent: Tue, July 24, 2012 8:52:28 AM
Subject: Re: [time-nuts] What's the easiest way to divide by 10 for Thunderbolt
reference output?
Sorry, should have said, ready built, got too many half finished jobs
on the go right now. FAR too many according to my wife....
A Tektronix DD501 will do divide by 10, or any number from 00002 to 99999.
-John
===============
Mine are not handy, so I'm not sure it has 50% output duty, but the
Ballantine
6130A Time Mark Generator is a potential candidate. It's not much more
than a
chain of 7490 dividers fed from a 10MHz source, and has a (non-nut)
ovenized
oscilltor built in. Even has synchronized multipliers that go up to
500MHz. I
couldn't resist buying a 2nd at Dayton this year, cost all of $5 from
a dumpster
diver late Sunday. A fair price is more in the $30 - $40 range, which is
what I
paid for my first one.
Bob LaJeunesse
From: Chris Wilson chris@chriswilson.tv
To: Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Tue, July 24, 2012 8:52:28 AM
Subject: Re: [time-nuts] What's the easiest way to divide by 10 for
Thunderbolt
reference output?
Sorry, should have said, ready built, got too many half finished jobs
on the go right now. FAR too many according to my wife....
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.
A Tektronix DD501 will do divide by 10, or any number from 00002 to 99999.
-John
Thanks, was hoping for something as a permanent, small and cheap
fitting, standalone. Don't really want to tie up my 7233 running
something to run something else IYSWIM? Was hoping China Town would
have the answer for low $$'s :)
--
Best Regards,
Chris Wilson.
Unfortunately, the TAPR T2-Mini divider
(http://www.tapr.org/kits_t2-mini.html) can't quite get to 1 MHz from 10
MHz with the PIC divider chip due to limitations in the chip architecture.
However, nothing says you couldn't "dead bug" in a decade divider chip
in place of the PIC, and let the T2-Mini provide the input conditioning,
output driver, voltage regulation, connectorization, etc. for you,
making it much a smaller project.
John
On 7/24/2012 8:18 AM, Chris Wilson wrote:
24/07/2012 13:14
My Racal Dana 9908 can take a 1 Mhz external reference. Inputting my
Thunderbolt at 10 MHz works, but shifts the decimal point over. I am
not sure if this has any other detrimental effects as to accuracy or
other? What's the easiest way to have a 1 MHz reference from the
Thunderbolt for this timer / counter please, yet retaining 10 Mhz for
my other devices that want a 10MHz reference signal? Thanks.
I think the HP 5087 Distribution Amp has a card that will do divide-by-ten.
-John
==================
Unfortunately, the TAPR T2-Mini divider
(http://www.tapr.org/kits_t2-mini.html) can't quite get to 1 MHz from 10
MHz with the PIC divider chip due to limitations in the chip architecture.
However, nothing says you couldn't "dead bug" in a decade divider chip
in place of the PIC, and let the T2-Mini provide the input conditioning,
output driver, voltage regulation, connectorization, etc. for you,
making it much a smaller project.
John
On 7/24/2012 8:18 AM, Chris Wilson wrote:
24/07/2012 13:14
My Racal Dana 9908 can take a 1 Mhz external reference. Inputting my
Thunderbolt at 10 MHz works, but shifts the decimal point over. I am
not sure if this has any other detrimental effects as to accuracy or
other? What's the easiest way to have a 1 MHz reference from the
Thunderbolt for this timer / counter please, yet retaining 10 Mhz for
my other devices that want a 10MHz reference signal? Thanks.
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.
Chris,
my vote is for the David Partridge 'time-nuts' frequency divider that
was discussed and optimised here in detail some time ago.
It divides everything you might need from the 10 MHz input. There are
separate outputs for 10 MHz, 5 MHz, 1 MHz, and one that can be
configured for 100 kHz / 10 kHz / 1 kHz / 100 Hz / 10 Hz / 1 Hz.
I think David might still have some populated boards.
Adrian
Chris Wilson schrieb:
24/07/2012 13:14
My Racal Dana 9908 can take a 1 Mhz external reference. Inputting my
Thunderbolt at 10 MHz works, but shifts the decimal point over. I am
not sure if this has any other detrimental effects as to accuracy or
other? What's the easiest way to have a 1 MHz reference from the
Thunderbolt for this timer / counter please, yet retaining 10 Mhz for
my other devices that want a 10MHz reference signal? Thanks.
John,
That's interesting to me. What exactly are the actual structural limitations of [that] pic?
-CH
On Jul 24, 2012, at 7:55, John Ackermann N8UR jra@febo.com wrote:
Unfortunately, the TAPR T2-Mini divider (http://www.tapr.org/kits_t2-mini.html) can't quite get to 1 MHz from 10 MHz with the PIC divider chip due to limitations in the chip architecture.
However, nothing says you couldn't "dead bug" in a decade divider chip in place of the PIC, and let the T2-Mini provide the input conditioning, output driver, voltage regulation, connectorization, etc. for you, making it much a smaller project.
John
On 7/24/2012 8:18 AM, Chris Wilson wrote:
24/07/2012 13:14
My Racal Dana 9908 can take a 1 Mhz external reference. Inputting my
Thunderbolt at 10 MHz works, but shifts the decimal point over. I am
not sure if this has any other detrimental effects as to accuracy or
other? What's the easiest way to have a 1 MHz reference from the
Thunderbolt for this timer / counter please, yet retaining 10 Mhz for
my other devices that want a 10MHz reference signal? Thanks.
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.