START
P
WHAT IS SYMPTOM OF BAND 3
PROBLEM?
I
I
I
UNlT COUNTS AFTER
SIGNAL IS REMOVED
VCO IS GENERATING
WRONG FREQUENCY. CONNECT
CONVERTER TO
A109J2. (VCO
REF.) IS FREQUENCY BETWEEN
400 MHz AND
500
MHz?
AND STABLE?
I
I
YES NO
0
LOCK CIRCUITRY ON
VCO NOT
0
LOCKED.
CONNECT A POWER SUPPLY
TO
A201J3. VARY VOLTAGE FROM
-2 TO
+9V. DOES THE VCO FRE-
QUENCY VARY FROM APPROX.
370 MHz TO APPROX. 510 MHz?
I.F. THRESHOLD BAD
UNlT DOES
NOT COUNT
WITH NO SIGNAL INTO THE
COUNTER, CONNECT A SCOPE
TO
A100J7 PIN 2. DOES IT CON-
TAIN A 60
ms
RAMP?
I"'
0
LOCK CIRCUITRY ON
A108 BAD.
CONNECT A SIGNAL WITHIN THE
OPERATING RANGE OF BAND 3
TO THE BAND 3 INPUT.
WITH A
SCOPE LOOK AT
A100J7 PIN 2.
IT SHOULD CONTAIN A COM-
PLEX WAVEFORM. DOES A POR-
TION OF THE WAVEFORM LOOK
LIKE PHOTO A
POWER METER OR
POWER METER ZERO CIRCUITS
SEE FIGURE 6-20.
POWER METER
PHOTO
A.
Figure
817.
Band
3
Scans by ArtekMedia © 2007
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