May. 2008 DD-7 2. With the F.BACK control turned down counterclockwise all the way, turn it clockwise to the 9 o’clock position. 3. VR Check (D.TIME) 3. Turning the control all the way counterclockwise again makes the CHECK LED light up red. Verify that the CHECK LED goes dark. Make the connections shown below to the INPUT and OUTPUT jacks on the DD-7, using the settings indicated. fig.DD-7-wave-2.eps_75 INPUT A: Input a rectangular wave at 400 Hz, 800 mVp-p. INPUT B: Input a rectangular wave at 400 Hz, 800 mVp-p. OUTPUT A: Connect the oscilloscope. OUTPUT B: Connect the oscilloscope. Set the oscilloscope to 500 mV/DIV, 1 ms/DIV, and coupling: DC. 1.
Verify that the D.TIME control is turned down counterclockwise all the way. fig.DD-7-wave-1.eps_75 The CHECK LED lights up orange. 4. Adjust the F.BACK control to the 12 o’clock position. With the control turned down counterclockwise all the way, turn it clockwise to the 12 o’clock position, and verify that the CHECK LED goes dark. At the 12 o’clock position, the LED lights up red. fig.DD-7-wave-3.eps_75 2. With the D.TIME control turned down counterclockwise all the way, turn it clockwise to the 9 o’clock position. Verify that the CHECK LED goes dark. 3. Turning the control all the way counterclockwise again makes the CHECK LED light up red. fig.DD-7-wave-2.eps_75 5.
Turn the F.BACK control clockwise all the way. Verify that while the control is being turned all the way clockwise from the 12 o’clock position, the CHECK LED stays dark. When the control has been turned clockwise all the way, the LED lights up red. fig.DD-7-wave-1.eps_75 4. Adjust the D.TIME control to the 12 o’clock position. With the control turned down counterclockwise all the way, turn it clockwise to the 12 o’clock position, and verify that the CHECK LED goes dark. At the 12 o’clock position, the LED lights up red. fig.DD-7-wave-3.eps_75 11