Tektronix TG8000 Service Manual

SDI7 module troubleshooting
Check the multiple frame
rates
The mainframe p
rovides three frame pulses which are used to set the module
timing relative to the rest of the instrument. Different frame pulses are us ed,
depending on the signal format the instrument is set for. Use this p rocedure to
investigate problems in that circuitry.
1. Connect the SDI7 outputs to a waveform monitor.
2. Apply power to the TG8000 mainframe.
3. Recall the F
actory Default preset as follows:
a. Press the MODULE button until TG8000 appears.
b. Press Enter button to select Preset.
c. Press the up (▲)ordown(▼) arrow button to select RECALL.
d. Press the left (◄)orright(►) arrow button to select Factory Default.
e. Press the ENTER button to reset the instrument to the factory default
settings.
f. Press the BACK button to r eturn the TG8000 main menu.
4. Ver i f
y that all four SDI7 signal outputs (SIGNAL 1A, SIGNAL 1B, SIGNAL
2A, and SIGNAL 2B) are set to provide a 59.94, 1080i format, 100% color
bar signal (factory default signal).
5. Check the DDS0:Phase and DDS1:Phase lock status, as described in the
Module Diagnostics. (See page 14-15, Check the module diagnostics.).
6. ChangetheSDI7channel1signalformatto50Hz:
a. Pre
ss the MODULE buttontoselectSDI7[x-1] (channel 1).
b. Press the FORMAT button to enter the SDI7 format menu.
c. Press the left ( ◄)orright(►)arrowbuttontoselect1080 50i.
7. ChangetheSDI7channel2signalformatto24Hz:
a. Press the MODULE buttontoselectSDI7[x-2] (channel 2 ).
b. Press the FORMAT button to enter the SDI7 format menu.
c. Press the left (◄)orright(►) arrow button to select 1080 24p.
8. Check the DDS0:Phase and DDS1:Phase lock status, as described in the
Module Diagnostics. (See page 14-15, Check the module diagnostics.).
If one of the formats (59.94 Hz, 50 Hz, or 24 Hz) works correctly, but the other
one does not, the mainframe sync pulse may be missing. Perform the Swap
modules procedure, below, to determine the source of the problem.
TG8000 Multiformat Test Signal Generator Service Manual 14–23

Tektronix TG8000 Specifications

General

Brand	Tektronix
Model	TG8000
Category	Portable Generator
Language	English