16
Subject to change without notice
3.1 Preliminary Instructions
To ensure proper conditions for the adjustment and to prevent
settings errors, the instrument must be prepared as follows:
– Allow a minimum warm-up time of 30 minutes at ambient
temperature (unit must be inside casing)
– Switch off the HM5014-2 and then switch it on again
– Set the HM5014-2 to the following:
– Center frequency 500 MHz
– Span 1000 MHz
– ATT 10 dB
– TG off
– RBW 1000 kHz
– VBW not activated
– Marker not active
– View A
– Test signal off
– Average not activated
– Max. HLD not activated
– Intens and Focus set to normal values (trace and readout
visible)
– 5 dB/Div not active
– Ref.-Level –20 dBm
– Instrument in Local mode (LED RM not lit)
The following sectins describe the adjustment procedures.
The values are specifi ed in the data sheet “Specifi cations”.
Additional introduction of errors caused by the measurement
equipment must be taken into account when adjusting the rated
values. All measurements will be performed with an external 10
MHz reference frequency with a minimum accuracy of 10-9.
3.2 Adjustments
3.2.1 Adjustment of supply voltages
The supply voltages must be in the intended range for the in-
strument to operate properly. A great variety of malfunctions
may occur in case of incorrect supply voltages.
The 144V, 32V, 12V and –12V supplies can be measured on the
pins of the unused 8 pin molex connector as indicated beow.
Figure 3-1: 8pin connector for supply measurement
Pin1 144V
Pin6 32V
Pin7 12V
Pin8 -12V
(In earlier units this connector may have a ribbon cable at-
tached)
+5 V
Figure 3-2: CPU board, showing the location for +5V
measurement.
The 5 Volt supply voltage can be measured on the CPU-Board
5th pin of the supply voltage connector shown in Fig. 3-2.
Adjustment of the voltages is made at the factory, in the very
unlikely event of having to readjust them, use RV1001 [indicated
in Fig. 3-3 below] to adjust the +144 Volts, and then use RV1003
to adjust the +12 and –12 Volts supplies. No other adjustments
are necessary at this point.
Figure 3-3: Location of RV1001
Enter the internal adjustment menu of the HM5014-2 by pres-
sing the keys “Intens” and “Focus” while switching on the ins-
trument. The time until the instrument emits a “beep” is about
10 seconds, then the 2 buttons can be released. Instead of the
standard screen display the adjustment “**menu**” display
will appear on the screen. The items
5dBADJ
TGL +1
TGL-10
OSCADJ
INTENS
FOCUS
TR-ROT
EEPNEW
appear on the screen, and to the left a cursor is shown. Items
can be elected by pressing the Center button for moving the
cursor upwards, and the Marker button for moving the cursor
downwards. Items are selected by pressing the Ref.-Level
button. The screen menu shown for each item is customized
for each adjustment operation. To leave the adjustment menu,
switch off the unit.
3.2.2 Check of CRT-XY Display adjustment
Select item „TR-ROT“ in the internal adjustment menu as de-
scribed in section 2.2.1. A set of 6 lines will appear on the CRT,
3. Adjustment
RV1001
3. Adjustment
RV1003
RV1005
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