Encoder Board NTSC

Set-up

1.Switch off power. Place encoder board on service extender. Genlock camera with black burst signal. Switch on power.

2.Connect oscilloscope via a vectorscope terminated with 75Ohm to the CVBS output of the camera.

3.Switch on colour bar.

Black balance

4.Turn chroma potentiometer R4 on encoder board fully clockwise (max. chroma).

5.Adjust the I and Q balance potentiometers for minimum unbalance in black.

Measure at:

CVBS out

Adjust with:

ZR203

ZR206

Required result:

Smallest possible

dot in centre of

vectorscope

6. Turn chroma potentiometer R4 on encoder board fully counterclockwise (zero chrominance).

CVBS amplitude

7. Adjust the CVBS gain potentiometer to obtain an output amplitude of 549mV (77 IRE).

Measure at:

CVBS out

Adjust with:

R14

Required result:

549mV

(77 IRE)

Correct:

0.1V10µS

100

90

10

0%

VA+549mV

White bar amplitude

8. Adjust the white amplitude potentiometer to obtain an output of 714mV (100 IRE).

Measure at:

CVBS out

Adjust with:

ZR213

Required result:

714mV

Correct:

0.1V10µS

100

90

10

0%

VA+714mV

Adjustments

Technical Manual LDK 20(S) - Studio Camera

4-43

Page 69
Image 69
Technicolor - Thomson LDK 20(S) technical manual Set-up, White bar amplitude