Rf Testing - Sony SPP-SS955 Service Manual

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5-3.

RF TESTING

This test is for checking the RF system without disassembling the
set in servicing. Perform measurement using the spectrum ana-
lyzer and jig antenna.
5-3-1. RF Testing method
Please follow the below instruction to perform RF test.
[Setting Condition]
Connect a receiving antenna to RF INPUT of Spectrum analyzer
and set the unit 10 cm (4 inches) away from the receiving antenna.
Measuring tool: Spectrum analyzer (equivalent to HP8595E)
Jig: Receiving antenna (for Spectrum analyzer)
10 cm
Jig antenna
(Utilize the antenna for handset)
10 cm
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L 13942296513
[Check the Transmission Wave]
Purpose
It is necessary to check spectrum wave of transmission wave which
is an important factor in order to confirm operational performance
of Spread Spectrum models. If this wave deviates from correct
wave form, normal data transmission cannot be made and, as a
result of that, possibility that occurrence of mute increases and
communication distance becomes shorter will increase.
Measuring process
• Setting Spectrum analyzer:
Center frequency : 903.6 kHz (CH1)
RBW
VBW
Span
• Setting Test mode:
Continuous Transmit mode (CH1 High Power)
(Refer to "Test Mode" on page 15)
• Measurement:
Measure transmitting wave.
• Specifications:
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Acceptable level [XdB] difference between the highest peak and
the lowest peak of odd side band (the first to seventh side band
from Center Frequency ; Transmission Frequency f
under 10 dB. (Refer Fig. 1 and Fig. 2)
.
If output wave form deteriorates, side band appears like Fig. 3
and Fig. 4.
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Spectrum
analyzer
Spectrum
analyzer
: 30 kHz
: 30 kHz
: 3 MHz (or 5MHz)
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8
• Transmission Wave:
ATTEN 10 dB
RL 0 dBm
MKR
903.392 MHz
–16.00 dBm
CENTER 903.600 MHz
RBW 30 KHz
XdB
–9
Q Q
3 6 7 1 3
ATTEN 10 dB
RL 0 dBm
MKR
903.233 MHz
–14.67 dBm
CENTER 903.600 MHz
RBW 30 KHz
: CH1) is
0
.
– 17 –
9 4 2 8
MKR
903.392 MHz
10 dB/
SPAN
VBW 30 kHz
Fig. 1
–3
5
–4
–5 3
1
–1
–6
4
–7
–2 2
–8
f
0
1 5 0 5 8 2 9 9 4
f f
–1 1
Fig. 2
MKR
10 dB/ 903.233 MHz
SPAN
VBW 30 kHz
Fig. 3
m
co
9 9
–16.00 dBm
5.000 MHz
SWP 50.0 msec
6
7
8
9
2 8 9 9
–14.67 dBm
5.000 MHz
SWP 50.0 msec