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D4.8
T869 Fault Finding
M860-00-Preliminary
30/06/98
Copyright TEL
4.5.2
Power Control
Approximate voltages (@ 260MHz) under normal operating conditions:
Forward & Reverse Power
Measurement
Output Power
40W
100W
forward power at IC1 pin 1
forward power at IC1 pin 2
reverse power at IC1 pin 8
reverse power at IC1 pin 2
2V
—
0.5V
—
—
3.2V
—
0.8V
N
Y
Y
Does low forward power alarm
LED light when output power
reduced to 60W using RV63?
Low Forward Power Alarm Check
Does output power adjust over
the range 20-100W using RV63?
RF Power Level Control Check
N
Check 12V DC present
on IC5 pin 8.
Check sense voltages
from directional coupler.
Check IC1 pins 1 & 8.
Check Q1 & Q11.
Check IC1 pin 14 >12V DC
when forward power low.
High Reverse Power Alarm Check
Check Q16 & Q17.
Check IC1 pin 7 >12V DC
when reverse power high.
Does high reverse power alarm
LED light when PA operated into
a mismatch of 3:1 or worse?
N
Y
Over-Temperature Shutdown Check
Does the output power reduce to
40W at high operating temperatures?
Earth IC3 pin 9.
Check IC1 pin 13 is at 0.6V.
Check IC1 pin 14 goes from
high to low when IC3 pin 9
is earthed. Check Q22.
N
Y
Power control OK.
The following voltage checks are all done with RV69
(driver power clamp) set to maximum.
Caution
Note:
A final confirmation of high temperature
shutdown and/or fan activation at high
temperatures can be obtained by heating
the earth pad of R193 to >130°C with the
tip of a soldering iron. Take care not to
damage R193.
Summary of Contents for T860 Series II
Page 6: ...AII M860 00 Preliminary 30 06 98 Copyright TEL...
Page 12: ...A2 4 Mechanical M860 00 Preliminary 30 06 98 Copyright TEL...
Page 18: ...BII M860 00 Preliminary 30 06 98 Copyright TEL...
Page 20: ...B1 2 T865 General Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 30: ...B1 12 T865 General Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 32: ...B2 2 T865 Circuit Operation M860 00 Preliminary 30 06 98 Copyright TEL...
Page 42: ...B2 12 T865 Circuit Operation M860 00 Preliminary 30 06 98 Copyright TEL...
Page 56: ...B3 14 T865 Initial Tuning Adjustment M860 00 Preliminary 30 06 98 Copyright TEL...
Page 58: ...B4 2 T865 Functional Testing M860 00 Preliminary 30 06 98 Copyright TEL...
Page 84: ...B5 20 T865 Fault Finding M860 00 Preliminary 30 06 98 Copyright TEL...
Page 86: ...B6 2 T865 PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 90: ...B6 6 T865 PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 110: ...T865 Preliminary PCB Information T865 Grid Reference Index Page B6 26...
Page 112: ...CII M860 00 Preliminary 30 06 98 Copyright TEL...
Page 114: ...C1 2 T867 General Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 148: ...C4 2 T867 Functional Testing M860 00 Preliminary 30 06 98 Copyright TEL...
Page 154: ...C4 8 T867 Functional Testing M860 00 Preliminary 30 06 98 Copyright TEL...
Page 170: ...C5 16 T867 Fault Finding M860 00 Preliminary 30 06 98 Copyright TEL...
Page 172: ...C6 2 T867 PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 176: ...C6 6 T867 PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 204: ...T867 Preliminary PCB Information T867 Grid Reference Index Page C6 34...
Page 206: ...DII M860 00 Preliminary 30 06 98 Copyright TEL...
Page 208: ...D1 2 T869 General Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 214: ...D1 8 T869 General Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 216: ...D2 2 T869 Circuit Operation M860 00 Preliminary 30 06 98 Copyright TEL...
Page 224: ...D3 2 T869 Initial Adjustment M860 00 Preliminary 30 06 98 Copyright TEL...
Page 230: ...D4 2 T869 Fault Finding M860 00 Preliminary 30 06 98 Copyright TEL...
Page 238: ...D4 10 T869 Fault Finding M860 00 Preliminary 30 06 98 Copyright TEL...
Page 240: ...D5 1 2 T869 PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 244: ...D5 2 2 T869 PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 254: ...D5 2 12 T869 PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...
Page 256: ...EII M860 00 Preliminary 30 06 98 Copyright TEL...
Page 258: ...E1 2 T860 VCO PCB Information M860 00 Preliminary 30 06 98 Copyright TEL...