Table of Contents
Advertisement
()54A
Model 654A
Section Il[
heavy
.a
pe or
SECTION III
CATE
OPERATING INSTRUCTIONS
3-1. INTRODUCTION.
e. Adjust the OUTPUT LEVEL attenuators and the
AMPLITUDE control for the desired signal output
3-2.
This section contains instructions and information
level. The algebraic sum of the meter indication
necessary for the operation of the 654A Test Oscillator.
and the attenuator setting gives the power level, in
[ncluded in this section are identification of controls,
dBm, into a load equal to the impedance selected
indicators and connectors, turn-on procedure
,
meter
by the [MPEDANCE pushbutton. [n Table 3-1, the
mechanical zero adjustment and operating instructions.
o
dBm and + 10 dBm levels are converted to
voltage for each impedance.
3-3. CONTROlS,lNDICATORS, AND CONNECTORS.
3-4
.
All operating controls, indicators and connectors of
the 654A are identified and described in Figure 3-1
.
SWITCH
THE
10
DBM
STEP
ATTENUATOR
DOWN
BEFORE
3-5. TURN-ON PROCEDURE.
CONNECT[NG
TO
SENS[T[VE
EQUIPMENT, SUCH AS THERMAL
3-6. OUTPUT
METER
MECHANICAL
ZERO
CONVERTERS, SO AS TO PREVENT
ADJUSTMENT.
DAMAGE FROM OVERLOAD[NG.
3 -7. The
Model
654A
output
meter
is
properly
Table 3-1. dBm/Voltage Conversion Chart
mechanically zero-set when the meter pointer rests over the
-I dBm mark. Zero-set the output meter to obtain
maximum accuracy and
mechanical stability in
the
following manner. With LIN E switch turned off, insert
pOinted object (such as tip of bal.1 point pen) into recess on
adjustment wheel, and rotate wheel until meter pointer
rests exactly over -I dBm mark.
3-8. PRIMARY POWER APPLICATION
.
a.
Before applying primary power to instrument, set
I 15 or 230 volt slide switch (S3) to position which
indica tes primary voltage to be used.
f.
Connect the load to the output connectors. Use
o
dBm
=
I m watt into rated load.
Impedance
o
dBm
+10 dBm
50 ohm
75 ohm
135 ohm
150 ohm
600 ohm
0.224 V rms
0 .274 V rms
0.367 V rms
0.387Vrms
0.775 V rms
0.707 V rms
0 .866 V rms
1.162Vrms
1.225 V rms
2.449 V rms
the UNBAL connector for 50 ohm and 75 ohm
b. Connect primary power to connector J
I.
Switch
loads and both connectors (BAL) for 135 ohm,
LINE switch (S I) to ON position
:
pilot lamp
150 ohm and 600 ohm loads
.
(DSI) will glow
.
3-10. OPERATING CHECK.
3-9. OPERATING INSTRUCTIONS.
3-11. Before
making measurements using the 654A,
a. Zero -set
meter
(Paragraph
3-7)
and
turn
perform the following front panel checks to ensure that
instrument on (Paragraph
3-8).
your instrument is operating
correctly.
b. Set
the
FREQUENCY
RANGE switch and
a. Turn AMPLITUDE control until white arrow on
FREQUENCY dial (with VERN[ER) to the
knob is pointing up; meter should indicate
desired frequency. (Dial reading multiplied by
approximately 0 dBm.
range setting gives the frequency in
Hz_
)
b.
Turn
AMPLITUDE
control
extreme
c. Connect a frequency counter to the rear panel
counterclockwise; meter should indicate -I dBm or
COUNTER OUTPUT, if desired
.
less
.
d.
Select the required output impedance by pressing
c. Turn AMPLITUDE control extreme clockwise;
the appropriate [MPEDANCE pushbutton.
meter should indicate + I dBm or greater
.
3-\
Advertisement
Table of Contents
