Tektronix 1730 Series, Инструкция по эксплуатации

Страница: 139 / 258

1730–Series Checks and Adjustments
5–23
f. Select the field square wave signal. Display the signal with the 2FLD
SWEEP.
g. CHECK – for less than 1% tilt across the high APL portion of the
display.
h. Set the 1730–Series VERTICAL to X5 gain.
i. Select 2LINE SWEEP and SWEEP MAG ON.
j. Display the 12.5T modulated pulse for NTSC and PAL–M (20T for
PAL). Position the baseline over the center 140 IRE (1 V).
k. CHECK – that the baseline of the modulated pulse varies less than 2%.
16. Check X5 Transient Response
REQUIREMENT – Transient response for the 2T pulse and 2T bar: preshoot
1% or less. Pulse–to–bar ratio: 1:1 within 2%. Overshoot: 4% or less.
Ringing: 4% or less.
a. Connect the black burst signal to the 1730–Series EXT REF and
terminate the remaining side of the loop–through input.
b. Turn SWEEP MAG OFF. Select X5 VERTICAL GAIN and EXT REF.
c. Install the Step Attenuator and insert 14 dB of attenuation in the input
signal path.
d. CHECK – for 1% or less preshoot and 4% or less overshoot and ringing
for the pulse and bar transitions.
e. CHECK – for a pulse–to–bar ratio within 2% of unity.
f. Disconnect signal from the CH–B INPUT.
17. Check Low Pass Filter Response
REQUIREMENT – Response at 15 kHz does not vary between FLAT and
LPASS by more than 1%.
a. Connect the modulated, 5–step linearity signal to the CH–B INPUT.
b. Select the 100–IRE (100%) FLAT FIELD/ALT LINEARITY setting of
the generator.
c. Select the 1730–Series LPASS FILTER and turn off X5 GAIN (X1).
d. Switch between LPASS and FLAT.