Nokia RH-77 Troubleshooting Manual page 21

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Step # Part
TP3 I+, I-, Q+, Q-
TP4 C728T
TP5 C711T
TP6 L708R (L708R
for Prod
Probe)
TP7 C731T
TP8 R702L
(C703R)
TP9 R703T (R701L,
R715T)
TP10 C734B
TP11 C712R, C744R
TP12 C710T, C704B
* The R, L, T, and B values at the end of the part numbers indicate the Right, Left,
Top, and Bottom side of the part respectively in
Issue 01 04/2005
Table 13: Rx IF Troubleshooting (Continued)
Typical
Value/
Function
Frequency
HP85024A
I/Q outputs 300KHz tone
of N700 for input:
881.22 MHz
19.2MHz In +6.5 dBm
19.2 MHz
19.2MHz Out +4 dBm
19.2 MHz
VHF VCO +1.0 dBm
367.2 MHz
VREF 1.35 Vdc
RX_IF_AGC 0.2 to 1.8 Vdc
VR7 2.7 Vdc
VR3 2.7 Vdc
VR6 2.7 Vdc
VIO 1.8 Vdc
©2005 Nokia Corporation
RF Description and Troubleshooting
Typical
Value
Comments
Frequency
Prod Probe
-69/-84 dBm Baseband differential
300 KHz outputs of the IF IC (N700).
To test: set the input to
881.22 or 881.82 MHz/-75
dBm to get a 300 KHz tone
when receiver is on channel
384 (881.52 MHz)
-22 dBm Sine wave input to N700
19.2 MHz from VCTCXO.
-25 dBm Square wave output of N700
19.2 MHz to baseband.
-61 dBm Rx VHF VCO - Fixed at 367.2
367.2 MHz MHz (Be careful not to load
the circuit with the probe.)
System reference voltage
1.35 Vdc from UEM.
AGC control Voltage. 0.2V =
Max Gain, 1.8 V = Minimum
Gain
VHF VCO Supply from UEM
VCTCXO buffer supply from
UEM.
Main supply to N700, from
UEM.
Digital circuits supply from
UEM.
Figure 13.
Company Confidential
2118 (RH-77)
Page 21