T856/857 Fault Finding
C5.17
Copyright TEL
5.7.6
T857 Exciter Drive Amplifier
Check
power rails.
Check VCO.
Drive amp. OK.
N
N
Y
Y
N
Y
Y
N
Y
N
Y
9V at Q304 collector?
0.5V at Q304 base?
9V at Q305 collector?
Key exciter &
lock synthesiser.
Y
N
9V at Q303
collector?
Y
>4V present on
IC300 pin 1?
Check IC300.
Check Q302
& Q303.
>2V RF at
VCO output?
N
>1V RF at R323?
N
Y
Check attenuator pad
R517, R518, R519.
>0.5V RF at
Q304 base?
Check C314, #C315,
#C316, Q304, L305,
D201, D202, D203.
>5V RF at
#C321, #R330?
N
Check Q304.
>1V RF at
Q305 base?
Check signal path
between Q304 & Q305.
>5V RF at
Q305 collector?
Check Q305.
Summary of Contents for T850 II Series
Page 12: ...12 M850 00 31 09 98 Copyright TEL...
Page 14: ...AII M850 00 31 09 98 Copyright TEL...
Page 20: ...A2 4 Mechanical M850 00 31 09 98 Copyright TEL...
Page 26: ...BII M850 00 31 09 98 Copyright TEL...
Page 28: ...B1 2 T855 General Information M850 00 31 09 98 Copyright TEL...
Page 40: ...B1 14 T855 General Information M850 00 31 09 98 Copyright TEL...
Page 42: ...B2 2 T855 Circuit Operation M850 00 31 09 98 Copyright TEL...
Page 68: ...B4 2 T855 Functional Testing M850 00 31 09 98 Copyright TEL...
Page 74: ...B4 8 T855 Functional Testing M850 00 31 09 98 Copyright TEL...
Page 94: ...B5 20 T855 Fault Finding M850 00 31 09 98 Copyright TEL...
Page 96: ...B6 1 2 T855 PCB Information M850 00 31 09 98 Copyright TEL...
Page 102: ...B6 2 2 T800 04 0000 RSSI PCB Information M850 00 31 09 98 Copyright TEL...
Page 108: ...B6 3 2 T855 PCB Information M850 00 31 09 98 Copyright TEL...
Page 115: ...IPN 220 01396 02 M850 00 T855 PCB Information B6 3 9 Copyright TEL 31 09 98...
Page 122: ...IPN 220 01396 02 B6 3 16 T855 PCB Information M850 00 31 09 98 Copyright TEL...
Page 124: ...CII M850 00 31 09 98 Copyright TEL...
Page 126: ...C1 2 T856 857 General Information M850 00 31 09 98 Copyright TEL...
Page 140: ...C1 16 T856 857 General Information M850 00 31 09 98 Copyright TEL...
Page 154: ...C2 14 T856 857 Circuit Operation M850 00 31 09 98 Copyright TEL...
Page 170: ...C4 2 T856 857 Functional Testing M850 00 31 09 98 Copyright TEL...
Page 176: ...C4 8 T856 857 Functional Testing M850 00 31 09 98 Copyright TEL...
Page 198: ...C6 1 2 T856 857 PCB Information M850 00 31 09 98 Copyright TEL...
Page 204: ...C6 2 2 T856 PCB Information M850 00 31 09 98 Copyright TEL...
Page 220: ...C6 3 2 T857 PCB Information M850 00 31 09 98 Copyright TEL...
Page 232: ...IPN 220 01398 02 C6 3 14 T857 PCB Information M850 00 31 09 98 Copyright TEL...
Page 234: ...DII M850 00 31 09 98 Copyright TEL...
Page 236: ...D1 2 T858 859 General Information M850 00 31 09 98 Copyright TEL...
Page 248: ...D2 2 T858 859 Circuit Operation M850 00 31 09 98 Copyright TEL...
Page 256: ...D3 2 T858 859 Initial Adjustment M850 00 31 09 98 Copyright TEL...
Page 264: ...D3 10 T858 859 Initial Adjustment M850 00 31 09 98 Copyright TEL...
Page 266: ...D4 2 T858 859 Fault Finding M850 00 31 09 98 Copyright TEL...
Page 282: ...D5 1 2 T858 859 PCB Information M850 00 31 09 98 Copyright TEL...
Page 288: ...D5 2 2 T858 PCB Information M850 00 31 09 98 Copyright TEL...
Page 293: ...IPN 220 01141 01 M850 00 T858 PCB Information D5 2 7 Copyright TEL 31 09 98...
Page 298: ...IPN 220 01141 01 D5 2 12 T858 PCB Information M850 00 31 09 98 Copyright TEL...
Page 300: ...D5 3 2 T859 PCB Information M850 00 31 09 98 Copyright TEL...
Page 305: ...IPN 220 01159 01 M850 00 T859 PCB Information D5 3 7 Copyright TEL 31 09 98...
Page 312: ...EII M850 00 31 09 98 Copyright TEL...
Page 316: ...E2 2 T850 VCO PCB Information M850 00 31 09 98 Copyright TEL...
Page 328: ...G1 4 T855 Link Selectable Features M850 00 31 09 98 Copyright TEL...
Page 332: ...G2 4 T856 857 Optional Features M850 00 31 09 98 Copyright TEL...
Page 334: ...G3 2 Talk Through Repeater M850 00 31 09 98 Copyright TEL...
Page 340: ...HII M850 00 31 09 98 Copyright TEL...
Page 356: ...I II M850 00 31 09 98 Copyright TEL...
Page 358: ...I1 2 Tools Required M850 00 31 09 98 Copyright TEL...
Page 366: ...I2 8 T855 856 857 SII SI Conversion M850 00 31 09 98 Copyright TEL...
Page 370: ...I3 4 T858 859 SII SI Conversion M850 00 31 09 98 Copyright TEL...