STRD-50 Product Guide - Component Engineering

STRD-50
Digital /Analog Sound Reader
for Simplex Apogee
Installation and Alignment
Copyright © Component Engineering, All Rights Reserved
Table of Contents
Chapter 1: Reader Kit Installation
Wiring the Readers and Power Supplies
Chapter 2: Reader Kit Alignment: Analog
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4
5
Analog Focus
5
Analog Azimuth
6
Analog Lateral
7
Analog Illumination
8
Analog Complete
9
Chapter 3: Reader Kit Alignment: Digital
10
Digital Illumination
11
Digital Lateral
12
Digital Azimuth
13
Digital Focus
14
Digital Complete
15
Chapter 4: Trouble in Paradise? Analog
Common Analog Problems, Symptoms, Errors and Bad Fortune
Chapter 5: Trouble in Paradise? Digital
Common Digital Problems, Symptoms, Errors and Bad Fortune
Chapter 6: Kick-Starting Digital Alignment
Basic Help on Getting There from Here
Chapter 7: Removing a Reader
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Chapter 1: Reader Kit Installation
The reader mounting plate
attaches to the casting with 1032x1/2" flathead Philips screws
as shown.
The LED standoff attaches to the
casting with 8-32x5/8" socket
head cap screws into
counterbored holes. These
screws will be hidden after the
next step. You may want to
thread lock them in place.
Next, the LED mounting plate
attaches to the standoff with 632x1/2" Blk flathead Philips
screws.
2
Slide each lens block over the proper threaded shaft. Each end of the hole has a bearing insert. Use care
not to catch the inner edge of the bearings and displace them. The short shaft with the cutout fits into the
slot on top of the lens block.
The analog reader is mounted on top.
Note the position of the spacers. There is one for each reader. One is outside the analog reader and the
other inside the digital reader. This spacer compensates for the distance between the analog and digital
soundtracks.
3
Wiring the Readers and Power Supplies
4
Chapter 2: Reader Kit Alignment: Analog
Analog Focus
Use a 5/32" Allen wrench to
unlock the analog reader
adjustments.
Prepare the cinema audio processor for alignment by ensuring that
both channels of the optical pre-amp are at equal gain.
Thread and run Dolby Cat. No. 69T. Use an R.T.A. to view the
frequency response.
Rotate the focus ring to fine-tune the focus. Results that are nearly
flat to 12K are usual.
5
Analog Azimuth
You may continue to run the Cat. No. 69P for this test. View with a dual trace
oscilloscope set to XY mode. Use a 5/32 Allen wrench to fine tune the reader
azimuth adjustment. An extremely narrow trace is the desired result.
A trace that "leans" the other direction indicates that the two channels are
wired in opposing phase. If this is the case. Correct and proceed.
6
Analog Lateral
Thread and run SMPTE P35-BT Use a dual trace oscilloscope to view the waveforms. A 7/16" nut driver
is used to adjust the reader laterally. The desired result is a minimal, equal signal on both channels. The
reader is set to read 100% track width. A very small waveform may be seen.
Thread and run Dolby Cat. No. 97. Use a 7/16" nut driver to adjust the reader laterally. The goal is to
minimize cross talk between the channels. Zero cross talk should be easy to achieve. The channels may
be at different levels until the LED is in perfect adjustment. You may want to recheck this setting after
that step.
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Analog Illumination
Thread and run Dolby Cat. No.566 Illumination uniformity test film. Use a 9/64 allen wrench to loosen
the socket head cap screw enough to permit moving the copper LED mount by hand. Ensure that both
channels of the optical pre-amp are at equal gain. Rotate the assembly to achieve the highest traces. Move
the assembly in and out to illuminate equally all six-frequency bands.
Pay most attention to the extreme left and right. In a dual system you may have to move the digital LED
out of the way a bit to give yourself adjustment room. Tighten the screw when adjustment is complete.
Minimal torque is required. The large surface area makes excessive tightening unnecessary.
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Analog Complete
The analog alignments have been listed in a logical order. Some of the adjustments are interdependent so
they may need to be repeated or perhaps re-checked. If all is well this is the time to lock down the reader
adjustments using a 5/32" allen wrench. One could also check that the socket head clamp screw holding
the analog LED in place is locked down properly.
The next step would be to set Dolby level using Dolby Cat. Number 69 T test film.
1. Set the processor optical pre-amp at 80% gain and the slit loss compensation at zero.
2. Adjust the LED current control on the analog LED power supply to achieve Dolby level.
3. Fine tune the pre-amp controls so both channels are at Dolby level.
4. If there is a significant difference in the required gain for each channel you may want to repeat the
LED alignment procedure.
5. If not................analog alignment is complete.
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Chapter 3: Reader Kit Alignment: Digital
Use a 5/32" Allen wrench to unlock the digital reader adjustments.
The digital alignment section includes snapshots from oscilloscope displays and screen shots from Dolby
DRAS reader alignment software. The directions for connecting and calibrating your oscilloscope are
included with the installation manual for your Dolby Digital Cinema processor. You will need a PC with a
serial port and a pin-to-pin cable to connect and run DRAS software. Most alignment representations do not
indicate perfect results. This is not an accident or improper alignment. Dolby Cat. No. 530 QC10 calibrated
digital test film has offsets hand printed on the film stock. There are error correction numbers for lateral
offset, azimuth and vertical jitter. The unique number on your particular length of film is the desired
reading on DRAS software. The film shown is Dolby Cat. No. 69. This film is used to make the QC10
calibrated test film. The error offsets are added along with a sticker that identifies it as Dolby Cat. No. 530.
DRAS software will not give a reading until the reader is in near perfect alignment. The steps are listed in a
way that assumes you will be making at least two passes. The first with the scope and the second to fine
tune with DRAS and the scope. It is a good idea to become familiar with all of the information relating to
the digital reader prior to installation. Use care not to plug the reader into the digital processor when the
processor is powered up. This will usually destroy the circuit board in the digital reader.
All adjustments are made while running the same test film. Either Dolby Cat. No. 530 or Cat. No. 69 P or
T. You may not be able to perform the alignment steps in the order they are presented here.
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Digital Illumination
You will need to have some signal
showing on your scope to begin.
There is help getting started in a
section entitled "kick-starting
digital alignment" that follows.
Use a 9/64" allen wrench to loosen
the socket head cap screw enough
to permit moving the copper LED
mount by hand. Rotate the assembl
to achieve the highest traces. Move
the assembly in and out to evenly
illuminate the entire digital block.
Pay close attention to the edges of
the digital burst. The desired patter
would be straight up the left side,
straight across the top and straight
down the right side. Some
unevenness will appear on the top
edge. Careful adjustment can
minimize this effect.
Tighten the screw when
adjustment is complete. Minimal
torque is required. The large
surface area makes excessive
tightening unnecessary. The last
step is to adjust the LED current
from the power supply to reach 4
volts of video.
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Digital Lateral
A 7/16" nut driver is used to
make lateral adjustments to the
reader. Dolby Digital test film
has error correction numbers
printed on it. It is usual to have
lateral error in the range of
+ or - 2.
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Digital Azimuth
Use a 5/32" allen wrench to
adjust the reader azimuth.
Digital test films from Dolby
have error correction numbers
printed on them. It is usual to
have azimuth error in the range
of + or - 2.
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Digital Focus
If you have gone through to this point using your oscilloscope you may be able to set the focus using
both the scope and DRAS.
Thread and run Dolby Cat. No. 69T. Use an oscilloscope and a PC running Dolby's DRAS program to
view the digital trace and see the focus statistic. Rotate the focus ring to fine-tune the focus. A
"hollowness" in the digital burst will be visible on the scope. Results in DRAS that are above 50 are
usual.
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Digital Complete
The digital alignments have been listed in a logical order. Some of the adjustments are interdependent so
they may need to be repeated or perhaps re-checked. If all is well this is the time to lock down the reader
adjustments using a 5/32" allen wrench. One could also check that the socket head clamp screw holding
the analog LED in place is locked down properly.
It is not unusual for new prints to report error rates of 2-3. If you achieve this result digital alignment is
complete.
If not.......A section dealing with digital troubleshooting is included.
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Chapter 4: Trouble in Paradise? Analog
Common Analog Problems, Symptoms, Errors and Bad Fortune
LEDs are not lit?
The AC power cables insert deeply into the AC socket on the LS-40 power supply. It may look plugged
in but not be fully inserted.
There are 2 fuses inside the LS-40 power supply. They are the smaller European style 5x20mm glass
fuses. .125 amp slo-blo if set for 110 Vac .0625 amp slo-blo if set for 220 Vac.
The switching logic to the LS-40 is reverse logic. Closed contacts are off. Open contacts are on.
No analog audio?
The LED power supplies are shipped with the current set to minimum. Some adjustment will be
necessary.
The analog pre-amp power wiring polarity is clearly marked on the plugs. The ground MUST be
connected at both ends. It is the circuit ground. Reference zero for the bi-polar supply.
Poor quality analog audio?
The polarity of the analog channels is clearly marked on the plug. Confusion in the channels ( dialog
from the surrounds ) is usually a result of out of phase wiring.
Many systems will require that the analog reader be grounded at both ends (reader and processor) . The
opposite of the time honored convention. Some will require that the reader ground be connected to the
circuit ground connections of the processor and that the audio cable shield be connected to the hood of
the DB9 connector. The latter is a rare occurrence.
It is possible that a slight maladjustment to an LED will allow projector micro phonics to enter the analog
audio. A fine-tuning of the LED position will not only make this effect vanish but will increase the signal
level and permit the use of less current to the LED.
Some older processors will not provide the proper load to our reverse scan readers , with very odd results.
A common fix is to put a 500-ohm resistor across each pair of audio channels. This value may not be
correct for all processors with this problem.
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Chapter 5: Trouble in Paradise? Digital
Common Analog Problems, Symptoms, Errors and Bad Fortune
The digital reader appears to be dead.
A Dolby Digital reader is at the heart a video camera. You can test it by shining a light source into the
lens and watching for a signal on your oscilloscope. If it is not functioning at all it is likely that the reader
was "hot plugged" into the processor. If this has happened a replacement digital circuit board is required.
The Dolby Digital reader has an odd scope trace.
It is possible to have a foreign object in three places. The scope trace would look similar in all cases. It
could be on the LED itself, the reader lens, or on the CCD chip that is inside the reader. Pictured below
are three traces of what you might see. If the dip is in sharp focus it is on the LED or the CCD. All parts
should be cleaned with a clean dry Q-tip.
These look very similar to a film scratch. The film scratch would show a dip in the digital burst but not in
the envelope. The sprocket hole would be untouched so the digital burst would show problems but not
the frame it appears to be in.
The Dolby Digital has a high error rate.
A Dolby Digital reader depends on the proper performance of the mechanical parts of the sound head.
The film must be properly registered , at a constant speed, with even and sufficient illumination. If you
have performed all the alignment steps successfully and the error rate reported is not satisfactory it is
likely that there is a mechanical problem with the projector/sound head. It could be making the film
move side-to-side or causing vertical jitter. In either case you will see the movement on your scope.
Either the trace itself will move side to side or the right hand side of the sync pulse on channel 2 will
have movement.
There are many causes for poor sound head performance. Worn or damaged mechanical parts, film
guidance parts, sprockets, bearings, etc. If the Digital reader is capable of making scope traces that
closely resemble those shown in the alignment procedures but play with a high error rate it is safe to
assume that the problem is mechanical and proceed in that direction.
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Chapter 6: Kick-Starting Digital Alignment
Basic Help on Getting There from Here
The first step is to get something up on your scope. The snapshots below show some of the typical scope
displays you will see as the alignment begins.
Channel 2 is up and
calibrated. Time to rotate
it off the screen.
Channel 1 is showing but
not triggering properly
from channel 2.
A little bit of digital
showing low and to
the left.
A little more digital
showing as the LED
is adjusted.
A better view of the
digital burst as the focus
is adjusted.
The lateral adjustment
puts the digital burst close
to the proper position.
The last trace shows a very good place to begin. The digital burst is in pretty good focus, has adequate
illumination and is close to the proper lateral position on the calibrated scope screen. You may be able to
run DRAS at this time. If so.....watch the number in the upper left hand corner of the screen. The statistic
"corners found" must be up around 80+ or the readings reported by DRAS are suspect.
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Chapter 7: Removing a Reader
A reader (digital or analog alike)
can be removed from the lens
block without disturbing the
azimuth or lateral adjustments.
To do so, loosen the lens clamp
screw and turn the focus ring in
the CCW direction. The reader
will slowly back out of the
assembly. At the point that the
lens tube is free of the focus ring
it can be pulled the rest of the
way out. The focus ring will be
free in the assembly. Remove it
for safekeeping.
To replace the reader. (Clamping
screw still loose of course) Place
the focus ring back into the slot.
Guide the reader into the
opening. The index pin on the
reader box fits into the recess,
between the azimuth adjustment
screw and the spring-loaded
plunger. Push the plunger out of
the way with a fingernail or small
screwdriver. The pin can now
move between them.
Next you need to start the threads
of the focus ring. The focus ring
will turn very smooth and easy
when it is in the threads properly.
If this is not the case. Pull the
reader out a little and try again.
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