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Step 1: |
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Disconnect 
from the summing amplifier.
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Step 2: |
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Set the function generator to produce a 30 Hz square wave.
Adjust the
DC OFFSET
and
AMPLITUDE
controls so that the signal has a low value of 0 V
and an high value of +10 V.
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Step 3: |
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Connect
Channel 1
of the scope to 
(Channel 2 should still be connected to 
).
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Step 4: |
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Connect the function generator output to
.
Turn on the power.
Adjust the function generator
FREQUENCY
control until the frequency of the
function generator output and the frequency of the sync
pulses are as close as you can get them.
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Step 5: |
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Turn off the power.
Discharge the capacitor in the loop
filter by shorting it out with a piece of wire for a few seconds.
Connect
to its input on the summing amplifier
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Step 6: |
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Turn on the power.
After a few seconds the sync pulses should stabalize
at the same frequency as the function generator, with
their rising edges 180 degrees apart.
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Step 7: |
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Slowly change the frequency of the function generator.
If you change it
very
slowly, the two signals should remain synchronized as the frequency
changes.
If you loose synchronization, stop and wait for the
loop to relock.
This may take a while.
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Step 1: |
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Disconnect the function generator from
.
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Step 2: |
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Disconnect 
from whatever it is connected to
(
or D/A channel 0).
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Step 3: |
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Wire the external signals from P5 and P6 into the circuit as follows
(pin numbers are for the interface board socket strip):
-
to pin 34
-
to pin 35
-
to pin 36
-
to pin 37
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Step 4: |
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At this point you need another camera to connect to.
Hopefully the group you have chosen for your partner has
been working as diligently as you have and is ready to go.
Draw straws, flip a coin,
submit to binding arbitration,
or otherwise
decide who will transmit first and who will receive.
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Step 5: |
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Get a double phone plug patch cord from the cart.
Plug one end into P5 on the transmitting system
and the other end into P6 on the receiver.
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Step 6: |
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Disconnect
from the summing amplifier on both systems.
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Step 7: |
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Turn on both systems.
At the transmitter, point the camera at interesting subject matter.
At the receiver, adjust the speed control until
and
are as close as possible to the same frequency.
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Step 8: |
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Look into the receiver eyepiece.
Try to center the image and keep it synchronized by adjusting
the speed control.
Are you successful?
Does the image stay synchronized?
Assuming the answer to either of
these questions is
"No," we're ready to try automatic synchronization.
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Step 9: |
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Turn off the power to the receiver.
Connect
to its input on the receiver summing amplifier.
(Leave it disconnected on the transmitter.)
Discharge the capacitor in the loop filter.
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Step 10: |
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Turn on the receiver power.
After a few seconds, the receiver should settle into synchronization
with the transmitter.
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Step 11: |
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Adjust the position control so that the
received image is centered vertically and horizontally.
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Step 12: |
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At this point the system is fully operational.
The transmitter group should now produce entertaining and
informative programming for the enjoyment of the receiving group.
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Step 13: |
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The resistor 
in the loop filter controls system stability
by keeping the closed loop poles out of the right half plane.
Experiment with larger (e.g. 220 k
) and smaller
(e.g. 2.2 k
) values.
What effects do these values have on the image?
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Step 14: |
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When the receiving group has had sufficient enjoyment, the
two groups should exchange roles and test the system
in the other direction.
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Step 15: |
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You have probably noticed by now that there are no numbered
Questions in this Lab.
Unfortunately, you're not off the hook yet.
You still have two things to do:
write your summary report and disassemble your breadboard.
Go on to the section "After Lab" to find out the details.
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