6
and a "mix" display mode can be used.
3. Set the TV channel to one of the major networks.
NOTE:
Make sure you are viewing a network originated signal. Do not make this adjustment
using a locally originated signal, such as from cable services, colleges, etc.
4. The TV monitor will "lock up" to either the BSG-50 or the off air signal, sometimes switching back and forth between
the two. There will be a relatively dark vertical bar going from top to bottom of the screen and it will appear to be
stationary or to be moving slightly from left to right or from right to left. The bar will also have a colored stripe in its
right half, and the stripe will be continuously changing colors.
5. Carefully adjust C26 for minimum movement of the bar across the screen, and then for the slowest change of the colored
stripe. It should be possible to have the stripe go through all its colors only a few times a second or less. Switch BSG-
50 power OFF and ON if necessary.
4.5 Setup, Sync, and Burst Levels
Set up the BSG-50 for a blackburst output and connect a waveform monitor or oscilloscope to observe one of the the
outputs. Make sure the blackburst signal is terminated at 75 ohms.
1. Because some adjustments interact, adjust the SETUP LEVEL first. Adjust for +7.5IRE units (53.6 mV P-P, +/-
5mV).
2. Next, adjust SYNC AMP for a level of -40 IRE units (285.7 mV P-P, +/-10mV).
3. Adjust BURST AMP for a level of 40 IRE units (285.7 mV P-P, +/-10mV).
4.6 SCH Adjustment
Before proceeding, make sure the subcarrier frequency adjustment step has been performed.
1. Connect a digital voltmeter or oscilloscope to pin-8 of IC U3 and adjust SCH1 ( C5) for a reading of 2.5V DC.
2. Disconnect the voltmeter or oscilloscope and fine adjust C5 for a reading of "0" + 5º SCH on the equipment you are
using to measure SCH.
4.7 Audio Tone Amplitude
Connect an voltmeter or oscilloscope to the 1KHz audio output of the BSG-50 and adjust 1KHz AMP for 775 mV RMS
(2.19 volts P-P) for 0 dBm/0dBu output level. If a 0 dBV output level is desired, adjust for a reading of 1 volt RMS (2.83
volts P-P).