When audio/video time code is specified if its on a audio track its called LTC
or Longitudinal Time Code and is generally IRIG-B, This is very uncommon
these days as it went out of common use about the time 1 reel to reel was
discontinued.
Most common today on NTSC is VITC or vertical
scmcgr...@gmail.com wrote:
When audio/video time code is specified if its on a audio track its called LTC or
Longitudinal Time Code and is generally IRIG-B, This is very uncommon these days
as it went out of common use about the time 1 reel to reel was discontinued.
IRIG is uncommon in
I'm looking for suggestions on a general circuit that can be used to
receive an external frequency reference (nominally a real clean sine
wave at, say, 10 MHz, although up to 100 MHz is possible) and turn it
into a real clean square wave. Galvanic isolation is a plus (a
transformer or
Wenzel has some discussion and circuits at:
http://www.wenzel.com/documents/waveform.html.
The Shera GPSDO made clever use of the input circuit of a 74HCT4046 PLL
chip for squaring.
John
On 12/8/2010 10:31 AM, jimlux wrote:
I'm looking for suggestions on a general circuit that can be
John Ackermann N8UR wrote:
Wenzel has some discussion and circuits at:
http://www.wenzel.com/documents/waveform.html.
The Shera GPSDO made clever use of the input circuit of a 74HCT4046 PLL
chip for squaring.
John
Doh... I was thinking that there was some vendor with ap notes on
Hi Pete,
I have that Raytheon QFHA Quadrofiliar Helix-Antenna, bought as used
part. This antenna is really good and does an excellent job directly
connected to Trimble Thunderbolt (5V alim.)! The cable can be fed Inside
via the mounting thread part, enjoy it,
Arnold
Am 03.12.2010 23:31, schrieb
Thanks for update on current LTC usage!.
In the studios I worked in in college with the old type-c decks we did use
IRIG-B but even then everyone was moving to VITC. As editing was moving away
from the razor blade and tape era to deck to deck on U-Matic decks!
Scott
Sent from my Verizon
Adding time code to video would be redundant. All video is already time coded.
It turns out the time code is required to support editing. Editors
don't actually move
bits of video data around. What they do is create and modify an EDL
which is a
text file with a list of all the cuts and effects
jimlux wrote:
I'm looking for suggestions on a general circuit that can be used to
receive an external frequency reference (nominally a real clean sine
wave at, say, 10 MHz, although up to 100 MHz is possible) and turn it
into a real clean square wave. Galvanic isolation is a plus (a
The document cited is full of plausible sounding but misleading
information, if you want really low jitter. This type
of oversimplification of the problem was present when the
HP53131 series counters were designed, with the result that
the Allan deviation of an external 10 MHz reference is
Just an FYI guys, I'm pretty sure the 3rd circuit down on the Wenzel page is
identical to the input circuit for the TAPR TADD-2 frequency divider. The
TADD-2 adds a transformer and load resistor. Schematic is in the manual
here:
http://www.tapr.org/~n8ur/TADD-2_Manual.pdf
-Bob
On Wed, Dec 8,
Professional cameras have a integrated VITC generator which in addition to the
time add the frame index to the time code which allows for creation of frame
level Edit Decision Lists.
Consumer cameras cheat and synthesize time. If you run a consumer tape through
a professional system you will
I can confirm that -- that's where I found it (and my schematic in the
TADD-2 manual gives credit to Wenzel)!
I chose that design mainly because it worked over a wide range of input
levels.
John
On 12/8/2010 12:48 PM, Robert Darlington wrote:
Just an FYI guys, I'm pretty sure the 3rd
Rick Karlquist wrote:
jimlux wrote:
I'm looking for suggestions on a general circuit that can be used to
receive an external frequency reference (nominally a real clean sine
wave at, say, 10 MHz, although up to 100 MHz is possible) and turn it
into a real clean square wave. Galvanic isolation
Chris Albertson wrote:
Adding time code to video would be redundant. All video is already time coded.
All *digital* video is timecoded..
Record that video on an analog 1/2 or 3/4 deck and you need the
timecode on the longitudinal audio track. Yes, primarily as you say, to
support editing.
One problem with this circuit is that tolerances in the resistors
produce an offset between the 2 transistor bases in addition to any
transistor mismatch,
It's better to share a single divider and short (eg a transformer
winding. Or at least connect them with a low impedance at low
Assuming a transformer coupled input (with biasing via a secondary center tap)
why not use a fast differential PECL to CMOS level translator? For example, the
IDT ICS508 will take 0.3 to 1.0 V p-p input and give 2.5, 3.3, or 5 V swing on
the output. The chip works down to DC and keeps the duty
One caveat with driving a CMOS gate input is that if it is overdriven so
that the input protection circuit diodes conduct then the output jitter
may increase substantially.
At least this appears to happen when overdriving 74HC04 inverters.
Once the input diodes conduct (5MHz sine wave input)
There has been times in the past where I needed to make broadcast
off-air recording that needed positive time indication. In those
cases I would record the station's audio on one track and one of the
WWV's on the other. I would start my recording early or let it run
past the end of the
One can estimate the resultant jitter from the input slew rate and the
circuit noise and bandwidth.
Too much bandwidth with a slow input slew rate increases the jitter
substantially over that possible with an optimal circuit.
Bruce
Robert LaJeunesse wrote:
Assuming a transformer coupled
On 12/08/2010 02:27 PM, scmcgr...@gmail.com wrote:
When audio/video time code is specified if its on a audio track its
called LTC or Longitudinal Time Code and is generally IRIG-B, This
is very uncommon these days as it went out of common use about the
time 1 reel to reel was discontinued.
On 12/08/2010 07:18 PM, jimlux wrote:
Chris Albertson wrote:
Adding time code to video would be redundant. All video is already
time coded.
All *digital* video is timecoded..
No, not all digital video. The time-code is optional in many of the
transfer formats.
Record that video on an
ECL has a high phase noise floor in the -140s.
Other than that, it works fine.
Rick Karlquist
Robert LaJeunesse wrote:
Assuming a transformer coupled input (with biasing via a secondary center
tap)
why not use a fast differential PECL to CMOS level translator? For
example, the
IDT ICS508
Yes, and thus if you are going to use a comparator or line
receiver (not recommended), then you should use the SLOWEST
one that still works, if you want to optimize jitter.
This is because the noise bandwidth is less.
Bruce Griffiths wrote:
One can estimate the resultant jitter from the input
On 12/08/2010 06:28 PM, Rick Karlquist wrote:
jimlux wrote:
I'm looking for suggestions on a general circuit that can be used to
receive an external frequency reference (nominally a real clean sine
wave at, say, 10 MHz, although up to 100 MHz is possible) and turn it
into a real clean square
On 12/08/2010 09:13 PM, Rick Karlquist wrote:
Yes, and thus if you are going to use a comparator or line
receiver (not recommended), then you should use the SLOWEST
one that still works, if you want to optimize jitter.
This is because the noise bandwidth is less.
For optimum result you need to
I was thinking about how good or how bad would result the use of an LVDS
line receiver ... but it is only a though :)
Regards,
Javier
El 08/12/2010 19:50, Robert LaJeunesse escribió:
Assuming a transformer coupled input (with biasing via a secondary center tap)
why not use a fast
Of all the ways to square a sine wave I think the best might be to use a PLL.
the raising edge of your output square wave would trigger a sample of the
input sine wave. The distance from zero volts of that sample is the
phase error.
The goal is to have the raising edge of the square wave happen
The Wenzel diff-amp circuit is OK but it will run out of steam before 100
MHz unless you use different transistors. On the other hand you really have
to go out of your way to corrupt the signal at the -125 dBc/Hz level. At
that level of play any decent comparator with the necessary slew rate
Hello The Net:
I estimate /B MBD to be in DM79lt, in Westminster, CO. Just NW of Denver.
Since I am in FN41sr, my LOB to is: 277.5 degrees ref true North
at a distance of 2,907.5 Km or 1806.4 miles.
I got the LOB and DX info from the BD2004 software at the
www.w1ghz.org site.
It
umm u lost me any help?
On Wed, Dec 8, 2010 at 6:05 PM, Stan, W1LE stanw...@verizon.net wrote:
Hello The Net:
I estimate /B MBD to be in DM79lt, in Westminster, CO. Just NW of
Denver.
Since I am in FN41sr, my LOB to is: 277.5 degrees ref true North
at a distance of 2,907.5 Km or 1806.4
Hi
I assume we're talking about a NDB (non directional beacon).
This time of year is pretty good for low frequency stuff. The thunderstorms die
down and you can really hear a *long* ways. The path you are talking about is
quite possible.
Bob
On Dec 8, 2010, at 6:05 PM, Stan, W1LE wrote:
Sorry for the confusion,
Not a non directional beacon (NDB) , but rather a part 15 beacon on 137 KHz.
some recent posts include :
On 12/8/2010 3:55 PM, C. Turner wrote:
I tried detecting MBD/QRSS30 from Utah - but nothing heard/seen.
Beacon MBD is on now, at 187.517 khz, QRSS30 mode.
I figured out what I did wrong. I cross posted from the lowfer reflector.
Please disregard.
I will be more careful in the future. Stan, W1LE Cape Cod
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
Hi
And take away all the fun of guessing what's going on
If you can indeed track a 1W signal from ~ Colorado, there might indeed be some
timing use for the system.
Bob
On Dec 8, 2010, at 8:32 PM, Stan, W1LE wrote:
I figured out what I did wrong. I cross posted from the lowfer
Darn, I was sure that was a coded message to space saying it was
safe to bring the Mother Ship in because we were all distracted
by tax cuts for the rich.
Bill Hawkins
-Original Message-
From: Stan, W1LE
Sent: Wednesday, December 08, 2010 7:32 PM
To: Discussion of precise time and
Recently I bought a Efratom Ru frequency standard from eBay and a
frequency divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a
1HZ output. Today I thought of a way to make a nice 60HZ so you can use
a mains-powered clock for the display (using amplifier and transformer
wired
My magnetic base hockey puck amplified GPS antenna for my Lucent receiver died.
I had purchased it at the Dayton Hamvention so I don’t remember the dealer.
I’ve found quite a few sellers on Amazon that are in the USA and their prices
are all about the same.
Does anyone have a recommendation?
On Wed, Dec 8, 2010 at 6:16 PM, Perry Sandeen sandee...@yahoo.com wrote:
My magnetic base hockey puck amplified GPS antenna for my Lucent receiver
died. I had purchased it at the Dayton Hamvention so I don’t remember the
dealer.
I’ve found quite a few sellers on Amazon that are in the USA
Recently I bought a Efratom Ru frequency standard from eBay and a
frequency divider chip that makes 1MHZ,100KHZ,25KHZ,10KHZ,100HZ and a
1HZ output. Today I thought of a way to make a nice 60HZ so you can use
a mains-powered clock for the display (using amplifier and transformer
wired
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