Panasonic KX-TG2248S Service Manual ▷ View online
13.7. Handset Reference Drawing
When connecting the Simulator and Equipments for checking, please refer to below.
IC801
IC204
IC205
IC201
IC202
32
25
16
17
LC-SHS_RF
9
8
1
D802
C805
L808
D801
C833
C823
C824
C867
C864
C835
C830
C831
L806
L801
L803
L805
C832
C801
C802
C857
C861
C869
C860
C856
C856
R811
R808
C814
C813
C815
C279
L201
L802
C809
R807
R806
C804
C803
C803
C806
R805
R805
C807
L804
C812
C811
R813
R812
C858
C859
C859
C829
C828
R802
R804
R803
C827
C826
R801
C825
C863
C862
C865
C866
C822
C820
C821
C816
C817
C819
C818
R810
L807
C868
C260
C257
C228
R215
C244
R325
R326
C221
C243
C247
R306
D201
C292
D204
D217
Q206
L203
SP-PHONE
L206
L207
HANDSET
C300
L210
CN203
C270
C285
RA201
C267
D207
BATTLOW
TPM
TPP
C220
Q212
Q201
Q202
SI
SO
WP
WP
TEST
C213
R243
D214
R265
R245
C259
R247
R230
C232
C230
C230
C236
C237
R222 C222
C226
C227
R228
R228
R279
R276
R278
R280
C225
C308
C310
R277
C307
R277
C307
C239 C229 R233
C234
C238
C269
C295
C256
R302
R226
R236 R244
C309
C306
R223
R237
R225
R250
R249
R253
R231
R219
R229
C217
C217
R235
R234
C280
R234
C280
C218
C223
D202
C317
C224
C224
C241
C231
C233
C205
C293
R239 C291
R238 R281
C294
R273
R273
R213
R274
R275
R275
R209
C203 R210
R270
R212
R246
R248
C274
C242
C214
R200
D211
D216
D216
D207
D208
D205
D206
L204
C303
L212
L211
C277
SCK BT
R242
C298
C299
C299
BATT2
BATT1
C318
D212
D213
D213
SPN
CS
VSS
VBAT
TX
RX
MICM
MICP
C304
C255
Q205
TCK
TDI
TMS
TDO
Q204
1
1
SPP
LED211
L208
L209
R303
L209
R303
L205
FL801
PbF
ANT
ANTG
IC203
X201
AC VOLT
METER
MONITOR SP
8
OSCILLOSCOPE
TPM
TPP
+
+
MIC_M
MIC_P
OSC
1.1KHz
10
10
150
SPP
SPN
AC VOLT
METER
HANDSET
OSCILLOSCOPE
DC2.60V
DC2.37V
DC2.30V
15
VBAT
VSS
A
A
V
Frequency
Counter
Counter
Spectrum
Analyzer
Analyzer
Digital
SG
SG
Digital modulation
Board*
Board*
50
CABLE
ANT
ANTG
f=1KHz
modulation:60KHz
modulation:60KHz
*Supplied from Production Engineer
Note: (*2) is refered to No.2 of Check Table for RF Block (P.41)
KX-
TG224
8
S
49
13.8. Frequency Table
Channel
TX/RX Frequency (MHz)
Channel
TX/RX Frequency (MHz)
1
2472.70400
21
2405.63050
2
2473.21425
22
2406.14400
3
2474.75150
23
2406.65425
4
2475.26175
24
2407.16775
5
2475.77525
25
2407.67800
6
2476.28550
26
2409.21525
7
2476.80225
27
2429.18325
8
2477.31250
28
2429.69675
9
2477.82600
29
2430.20700
10
2478.33625
30
2430.72050
11
2478.84975
31
2431.23075
12
2479.36000
32
2431.74425
13
2479.87350
33
2432.25450
14
2402.04900
34
2433.79175
15
2402.55925
35
2434.30200
16
2403.07275
36
2434.81550
17
2403.58300
37
2435.32575
18
2404.09650
38
2435.83925
19
2404.60675
39
2436.34950
20
2405.12025
50
KX-TG2248S
14 DESCRIPTION
14.1. Frequency
The frequency range of 2402.04900 MHz ~ 2479.87350 MHz is used. Transmitting and receiving channel between base unit and
handset is same frequency. Refer to the Frequency Table.
handset is same frequency. Refer to the Frequency Table.
14.2. Time Division Duplex (TDD) operation
Transmission/reception between the base unit and handset is performed by time-sharing as shown in Fig. 7. 1 slot time of
transmission and reception is 1mS. Same frequency is used in transmitting and receiving. The figure shows an example; the
frequency of 3ch is used in transmitting between the base unit and handset.
transmission and reception is 1mS. Same frequency is used in transmitting and receiving. The figure shows an example; the
frequency of 3ch is used in transmitting between the base unit and handset.
Fig. 7
14.2.1. TDD Frame Format
The TDD frame is 2mS in length. Each subframe contains 128 bits of 7.8µS duration.
Each subframe consists of the following four fields:
•
•
A 1-bit Preamble field
•
•
An 8-bit Data Channel field
•
•
An 16-bit Sync Word
•
•
A 72-bit ADPCM Payload (Parity 8-bit)
51
KX-TG2248S
14.3. Signal Flowchart in the Whole System
Reception
CN1 of the base unit is connected to the TEL line, and the signal is input through the bridge diode D4. While talking the relay
(Q4) is turned ON and amplified at the amplifiers Q50, then led to DSP (IC201). DSP generates ADPCM signal. The ADPCM
signal is input to RFIC (IC801) of RF UNIT. RFIC outputs FSK modulated RF signal. The RF signal is passed through filter
(IC801) to be transmitted from the antenna. As for the handset, RF signal from the antenna is input to RFIC passing through
filter (IC801) then input to DSP (IC201). DSP performs ADPCM decoding to convert the signal into the voice signal, then it is
output to the speaker.
(Q4) is turned ON and amplified at the amplifiers Q50, then led to DSP (IC201). DSP generates ADPCM signal. The ADPCM
signal is input to RFIC (IC801) of RF UNIT. RFIC outputs FSK modulated RF signal. The RF signal is passed through filter
(IC801) to be transmitted from the antenna. As for the handset, RF signal from the antenna is input to RFIC passing through
filter (IC801) then input to DSP (IC201). DSP performs ADPCM decoding to convert the signal into the voice signal, then it is
output to the speaker.
Transmission
The voice signal input from the microphone is led to DSP (IC201). The DSP generates ADPCM signal. As well as the reception,
it is converted into the RF signal by RFIC (IC801). Passing through filter (FL801), it is transmitted from the antenna. As for the
base unit, RF signal from the antenna is input to RFIC (IC801) passing through filter (FL801) then input to DSP (IC201). DSP
performs ADPCM decoding to convert the signal into the voice signal. The voice signal is amplified at the TX amplifier (Q1), then
output to the TEL line (CN1) through the relay (Q4) and bridge (D4).
it is converted into the RF signal by RFIC (IC801). Passing through filter (FL801), it is transmitted from the antenna. As for the
base unit, RF signal from the antenna is input to RFIC (IC801) passing through filter (FL801) then input to DSP (IC201). DSP
performs ADPCM decoding to convert the signal into the voice signal. The voice signal is amplified at the TX amplifier (Q1), then
output to the TEL line (CN1) through the relay (Q4) and bridge (D4).
52
KX-TG2248S
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