Adjusting the Display
Signal Compatibility
The PA 300 processes
Potentiometer Adjustments
The PA 300 achieves superior amplification by using two independent peaking potentiometers: LF for streaking adjustment and HF for detail adjustment.
The goal in adjusting the PA 300 Gain and Peaking potentiometers is to produce a sharp image (i.e., an image free of streaking or smearing) on the attached display.
An oscilloscope is required for the most accurate gain adjustment, but gain can also be adjusted by observation. The following instructions explain how to adjust the gain with and without the use of an oscilloscope. An oscilloscope is not necessary for the peaking adjustment.
Adjusting gain with an oscilloscope
To adjust the Gain potentiometer using an oscilloscope:
1.Remove the cable from the source and attach a VTG 300 test generator to this cable.
2.Use the White Field test pattern for the VTG 300 setting.
3.Remove the far end of the cable from the projector and attach the oscilloscope using 75 ohm termination.
4.Use an Extron Tweeker to adjust the Gain potentiometer for a 0.7
5.Once gain is successfully adjusted, replace the source and display cables.
6.See "Adjusting the peaking" on the following page.
Adjusting gain without an oscilloscope
Use an Extron Tweeker to turn the Gain potentiometer until the image reaches the desired level of brightness.
