equipment to warmup and stabilize.
b. Position controls of microwave link analyzer
8. Back-to-Back Flatness
Check
(MLA) (A4) as listed in (1) through (3) below:
NOTE
NOTE
The following procedure describes a com-
The p&ion settings listed below are applica-
prehensive operational check of the TI.
ble to Hewlett-Packard Models 3702B and
a Performance Check
3710A. If other models have been furnished,
these settings will require modification. Refer
control fully clockwise and adjust the Y EXT OFFSET
to the Microwave Link Analyzer Operator's
control to return the Y1 TRACE as near as possible to
Handbook.
the center of the MLA oscilloscope.
(1) Position MLA oscilloscope (IF/BB receiver)
(2) Adjust the MLA oscilloscope Y1 GAIN control
controls as follows for preliminary adjustment of
to mid-position.
oscilloscope.
(3) Connect cable assembly (B7) to the MLA
(a) Y2 DISPLAY switch to IF.
(b) Y1 and Y2 GAIN controls fully coun-
oscilloscope EXT INPUT connector as shown in fig. 1.
(4) Adjust the MLA IF/BB receiver IF FRE-
terclockwise.
QUENCY control to display a zero beat "birdie" at the
(c) Y1 and Y2 POSITION control to midposition.
left end graticule line of the MLA oscilloscope.
(d) INTENSITY control adjusted as necessary
(5) Set TEST INSTRUMENT CALIBRATE
to obtain two spots on MLA oscilloscope.
switch to 2 MHz.
(e) FOCUS and ASTIGMATISM controls ad-
(6) Adjust the MLA oscilloscope X PHASE SHIFT
control to superimpose the 2 MHz marker birdies on
(f) X2 DISPLAY switch to SPECTRUM.
(g) X GAIN and X POSITION controls adjusted
both traces.
for a 10 cm (centimeter) display on MLA oscilloscope.
(`7) Set MLA oscilloscope BLANKING switch to
(h) TRACE ALIGN control should be adjusted
ON.
to obtain parallel traces on the MLA oscilloscope.
(8) Set TI CALIBRATE switch to 1 dB (decibel).
(L) Y2 POSITION control fully counterclock-
(9) Adjust MLA Y1 GAIN control to obtain an 8
wise.
cm display on MLA oscilloscope (1 dB/8 cm-O.125
dB/cm).
(10) Adjust test oscillator (A6) for an output level
of +3 dBm (decibel referred to one milliwatt) and fre-
(a) SWEEP selector switch to INT.
(b) SWEEP WIDTH control set to 15 MHz
quency for a 100 kHz (kilohertz) indication on
(megahertz).
electronic counter (AS).
(11) Disconnect cable assembly (B6) (fig. 1) from
electronic- counter and connect it to the TI EXT
MARKER INPUT connector.
(e) IF ATTENUATOR 10 dB pushbutton
depressed.
CY control to 71 MHz and the SWEEP WIDTH control
(f) IF VERNIER control set to 0.
to 2 MHZ.
(g) AUX OUTPUT switch to 70 MHZ XTAL.
(3) Position MLA oscilloscope controls as follows
(13) Set TI CALIBRATE switch to 2 MHz.
to complete the preliminary setup.
(14) Readjust these controls slightly as necessary
to position a 2 MHz marker birdie at the right hand
graticule line and a 100 KHz marker birdie at the left
(b) SWEEP SOURCE switch to EXT.
(c) BLANKING switch to OFF.
hand graticule line on MLA oscilloscope display. (These
(d)) Y1 DISPLAY switch to EXT.
adjustments must be made carefully because harmonic
(e) Y2 DISPLAY switch to IF.
signals are also present on the display).
(15) Disconnect cable assembly (B6) from the TI
RKERS switch to OFF.
EXTERNAL MARKER INPUT connector.
POSITION control to center the Y1
(16) The MLA oscilloscope trace now displays sig-
nals between 100 kHz and 2 MHz.
(17) Adjust MLA oscilloscope Y-EXT OFFSET
listed in (1) through (3)
control to place the 2 MHz part of the trace on the
ATTENUATOR (dB) 30 dB pushbutton switch
center horizontal graticule line.
(18) Set TI CALIBRATE switch to OFF. The
(2) GAIN switch set to X10.
amplitude "ariations of the trace between 100 kHz and
2 MHz will be leas than 0.8 cm. (1 cm- 0.125 dB).
(3) CALIBRATE switch set to OFF.
d Energize equipment and allow sufficient time for
(19) Set TI CALIBRATE switch to 2 MHz.