Tektronix 570, Manual

Page: 50 / 134

A
B
F i g . 5-5. A. The display seen before theCurrent Balancing c a p a c i to r(s)
are adjusted and connected properly. B . The display with properly
connected and a dj u sted current balancing capacitOr(s).
Allow the instrument to warm up for about
5 minutes .
Now observe the eye-opening of
the loop on the crt.
If
the loop is a st raight
line then no further adjustment is necessary.
If the loop has an eye -opening then one of the
following configurations , which brings the loop
the closest to a straight line, should be used.
The variable capacitors must be adjusted for the
s mallest eye-opening each time a new con­
figuration is used.
CAUTION
D amage to the instrument may result
if an end of C 3 1 5 and C316 are tied
to the same transformer terminal.
T310 Current Balance Capacitor Connections
Configuration
C315
C316
1
Not connected Connected between terminals
5 and
8
2
Not connected
Connected between terminals
7
and
8
3 Not connected
Not c o nne cted
4
Connected to
Not
connected
terminal
5
5
Connected to Not connected
terminal 7
6 Connected to
Connected between terminals
5 7
and
8
7
Connected
to
Connected between terminals
7 5
and
8
2 1 . Adjusting G R I D (C502) a n d S C R E E N
(C509) Current Balance Ca pacitors
Turn the PLA TE-SCREE N-GRID Control to
G RID. C502 is connected and adjusted to give
the least eye -opening in the loop.
C502 Connections
C onfiguration
Connection
1
No connection
2
Lead connected to terminal
1 4
of T501
3
Lead connected to terminal
16 of T501
Now set the PLA TE-SCREEN-GRID Control
to SCREEN. Connect and adjust C509 to give
the least eye opening.
C 509 Connections
Configuration
Connection
1 No connection
2
Lead connected to terminal
7 of T501
3
Lead connected to terminal
9 of T50l
5 - 8
C alibration Procedure - Type 570
AA