EIP 545A - Page 60

CHECK BAND 2
OPERATION FROM 10
MHz TO
190 MHz (BAND 2A). DOES BAND
2A WORK PROPERLY?
1 4 L.O. SELECT CIRCUITRY ON
A109 BAD.
CONNECT A 50 MHz, -20
dBm
SIGNAL TO THE BAND 2 INPUT.
CONNECT A SCOPE TO
Al09TP12.
IS A109TP12 A TTL HIGH?
SIGNAL SELECT CIRCUITRY ON
A109 BAD.
ISOLATION AMP,
200 MHz L.P.F.,
I.F. AMP, OR BAND 2 LOCK DET.
Figure 615. 200 MHz Test
CHECK SIGNAL AT A201A-J2
I
II
CHECK A109U3 PIN 3. IS IT AN
ECL LEVEL
200 MHz CLOCK?
NO OUTPUT
OTHER
I I
YES
L.O. BUFFER OR DIVIDE BY 2 ON
A109 BAD.
i
VCO BAD
THAN
400 MHz
-
7
400 MHz
SIGNAL SELECTOR
ON A109 BAD
FREQUENCY
PHASE LOCK CIRCUITRY ON
A108 BAD.
Figure 616. Band 2
Scans by ArtekMedia © 2007