RCA 54-45 Manual page 27

tests . These tests will also assure you that the instrument is in proper working condition.
However, do not attempt this procedure before all final checks have been completed and
initial adjustments have been made as described in the MAINTENANCE section.
1. Set the INTENSITY, VERT. GAIN and HORIZ . GAIN CONTROLS at their furthest counter­
clockwise positions . Set the SWEE P RANGE switch at EXT. HORIZ.
2. Set the FOCUS , VE RT. POS. , and HOR. POS. controls at the center of their ranges.
other controls may be set at any position.
3. Insert the power cord into a 105 - 125 volt, 60 cycle a-c outlet.
Turn the INTENSITY control clockwise (on), and the pilot lamp should light.
4 .
to warm up for about a minute. Then gradually turn the INTENSITY control clockwise until a spot
appears somewhere on the screen of the cathode-ray tube. If the spot does not appear, adjust the
VE RT. POS . and HOR. POS . controls slightly, as the spot may be off screen.
5. Adjust the VERT. POS . and HOR. POS. controls until the spot is in the exact center of the
screen, and then adjust the FOCUS control for the sharpest image .
Notice that for every setting of the INTENSITY control, there is a best setting for the FOCUS control.
Now adjust the astigmatism control on the right hand side of the cabinet for the smallest, roundest
spot possible.
6. Set the SWEE P RANGE switch at any of the internal linear sweep positions . Note that the spot
extends to a horizontal line . This is the linear horizontal sweep. The sweep has a fixed amplitude
designed to provide full screen horizontal deflection, and is not affected by the HORIZ. GAIN control.
Set the SWEEP RANGE switch at EXT HORI Z . Notice that the horizontal line returns to a
7.
spot, as the horizontal amplifier is now connected to the HORIZ. INPUT and ground terminals.
signal applied to the HORIZ. INPUT and ground terminals will cause the line to lengthen horizontally
in proportion to the peak value of the applied signal.
effective .
8. Set the SWEEP RANGE switch at 60 C PS LINE . The horizontal line on the screen is the 60-
cycle sine sweep, having a fixed amplitude designed to provide full screen horizontal deflection. Here
again, the HORI Z . GAIN control has no effect.
Connect one of the 6. 3 VAC jacks at the rear to the VERT. INPUT terminal.
9.
SELEC TOR at INT. , the VERT. ATTENUATOR at LO ,the SWEE P RANGE switch at 10- 100, the SWEE P
VERN. control a t MIN. Now adjust the VERT. GAIN control until the pattern extends about two- thirds
the height of the cathode- ray tube. The pattern will not be clear because of its rapid horizontal drift.
Advance the setting of the SWEEP VERNIER gradually until two sinewaves of power line frequency
appear and remain stationary on the screen.
NOTE 1: In rotating the SWEEP VE RNIER, it will be noticed that the drift of the pattern slows
down as certain critical frequencies are approached, and then reverses direction when
the critical frequency is passed. At these critical frequencies, a clear pattern can be
discerned. These critical sweep frequencies are sub-multiples of the signal frequency,
or the signal frequency itself (when only one cycle of the signal is displayed) . The pat­
tern is locked in at sub- multiples of the signal frequency when it is desired to view
more than one cycle of the signa�. The sweep frequency is equal to the signal frequency
divided by the number of complete cycles displayed on the screen. For example, if two
complete cycles of the 60 cps signal are displayed, the sweep frequency is 30 cps.
WARNING
This instrument will not operate, or operate
improperly and even be seriously damaged if
connected to any other type of power line (such
as de , 25 cycle ac, or an ac line above 125
volts).
26
Do
not make the spot too bright!
In this position the HORIZ . GAIN control is
All
Allow the unit
Any
Set the SYNC