Motorola T2260, Service Manual

Page: 29 / 121

29 4/3/01
Troubleshooting
receiver experiences 0.5 % FER. (The specifications for these two levels are -116 dBm and -104
dBm, respectively) In this portion of the service notes, we will consider each stage in its sche-
matic representation and will make some points about each block. DC levels and RF levels will
be noted. In PCS Receiver line up presentation, RF levels noted in the Rx Sections are approxi-
mate based on -70 dBm input power in the Center of the Band (1960 MHz, CH600) at the
mechanical switch and do not necessarily reflect the levels measured with high impedance
probe. Frequency of operation and channelization 1900 MHz Receiver Band 1930 to 1990 MHz
1900 MHz Channelization 1-1200, Frequency = 0.05 * Channel# +1930
Block Diagram of PCS Reciever
Tx Block Diagram
The Shark Transmitter line-up is a little different with Caliber design, Shark used ME3 IC and
doesn’t use isolator and electrical RF switch. Unlike MANTA, this is done with two separate line-
ups. The line-up splits in the ME3C, and recombines into the diplexer. The maximum output
power supplied to the antenna is: Analog:24.5 dBm PCS CDMA:23.5 dBm
Zif_Syn
LO_1900
1900 TX Section
Z-Match
ANT
ANT
Duplexer 1900 Duplexer 1900
I.L. 2.5 ~ 4.0 dB I.L. 2.5 ~ 4.0 dB
Freq Freq . 1930~1990 MHz . 1930~1990 MHz
Ref. Des. Ref. Des. FL10 FL10
LNA
LNA
Gain 15 dB Gain 15 dB
NF 1.8 dB NF 1.8 dB
IIP3 5.5 dBm IIP3 5.5 dBm
ATT 1
ATT 1
I.L 0.3 dB (@OFF) I.L 0.3 dB (@OFF)
I.L 25 dB (@ ON) I.L 25 dB (@ ON)
Combo (RF side) Combo (RF side)
I.L. 2.0 ~ 3.0 dB
I.L. 2.0 ~ 3.0 dB
Freq Freq . 1930~1990 MHz . 1930~1990 MHz
Ref. Des. Ref. Des. FL20 FL20
Mixer
Mixer
Gc Gc 12 dB 12 dB
NF 8 dB NF 8 dB
IIP3 -1 dBm IIP3 -1 dBm
IF SAW IF SAW
I.L. 10 dB I.L. 10 dB
Freq Freq . 109.8 MHz . 109.8 MHz
Ref. Des. Ref. Des. FL200 FL200
IF AMP
IF AMP
Gain 12 dB Gain 12 dB
NF 3.5 dB NF 3.5 dB
IIP3 -10 dBm IIP3 -10 dBm
Band Switch Band Switch
I.L. 1.0 dB(PCS) I.L. 1.0 dB(PCS)
Ref. Des. Ref. Des. FL13 FL13
Coaxial Switch Coaxial Switch
I.L. 0.3 dB I.L. 0.3 dB
Ref. Des. Ref. Des. J10 J10
ANT Match ANT Match
To Test Set Up
Offset VCO Offset VCO
( Band Shift ) ( Band Shift )
Combo (LO side Combo (LO side
) )
I.L. 1.8 ~ 3.0 dB I.L. 1.8 ~ 3.0 dB
Freq Freq . 2040~2100 MHz . 2040~2100 MHz
Ref. Des. Ref. Des. FL20 FL20
Celeritek
AM PS PA
ANTENNA
ACCESORY
CO NNECTOR
AMPS
DUPLEXER
IL = -1.7dB
SAW
FILTER
IL = - 2 dB
COUPLER
IL = -0.25 dB
RF DETECT
Tx I
Tx Q
ME3C
AMPS LO
979 - 1004 M Hz
LC FILTER
FO= 154. 65/ 189. 8 M Hz
IL= - 4.0 dB
Celeritek
PCS PA
Z IF SY N
To RX
Ceramic
FILT ER
IL = - 3 dB
Balun
Balun
PCS LO
2039 - 2100 M Hz
PCS
DUPLEXER
IL = -3dB
Diplexer
IL = -0.5d B
Antenna
Switch
IL = -0.2dB
COUPLER
IL = -0.25 dB