CRT DISPLAY ADJUSTMENTS

TM 11-5820-917-13

5-22. To make the receiver adjustment, the direction and rate of drift on the CRT

are determined. Then, if' the display is drifting downward, the front panel fine

control (STD ADJ) is turned clockwise; if the display is drifting upward, the STD

ADJ control is turned counter-clockwise. One full turn of the front panel STD

ADJ control will compensate for a drift of approximately 10% of CRT height per 24

hours for 2-30 MHz sweep, or 0.5 milliseconds per 24 hours. (One full turn will

compensate for a drift of 5% of CRT height per 24 hours for 2-16 MHz sweep,)

If the STD ADJ control adjustment range is insufficient (at physical limits which

are 20 turns end to end) to make the correction, it should be recentered, and the

adjustment made on the course control located on the 6025, assembly 1A6 (figure

5-3). The control is adjusted in an opposite direction to that of the front panel

STD ADJ control. For coarse control adjustment, turn counter-clockwise if dis-

play is drifting down; turn clockwise if display is drifting up. One turn of the

coarse adjustment control will compensate for a drift of 100% of CRT height per 24

hours (5 milliseconds per 24 hours) for a 2-30 MHz sweep, or 50% of CRT height for

2-16 MHz sweep.

5-23. CRT DISPLAY ADJUSTMENTS . Controls for the CRT drive and synchroni-

zation signals are adjusted following replacement of circuit elements or when dis -

continuities are observed in the position or linearity of the display. The bright-

ness control for the CRT is on the front panel and is an operator adjustment.

(Refer to Section 3, and check brightness adjustment). The schematic diagram of

figure FO-18 should be referenced for location of adjustments. To perform the

adjustments described in paragraphs 5-24 thru 5-27, the following disassembly

actions must be performed: