Section 6
TROUBLESHOOTING HINTS
A) 91/3 will not turn on; nothing happens when ON switch is pushed.
1) External AC wiring, fuse or circuit breaker may be open.
2) Amplifier cover not in place; cover safety interlock open.
3) Fuse F1-F4 open or missing; check fuses with an ohmmeter.
4) Step-start resistor R6or R7 open.
B) Amplifier turns on but no HV is indicated by the multimeter LED bargraph.
1) Multimeter selector switch in wrong position, e.g., Ip.
2) Possible HV circuit fault.
3) HV sampling resistor in power supply damaged.
4) Transformer plugged into power supply incorrectly.
C) Amplifier turns on but no multimeter indications; other LED bargraphs are operative.
1) Low voltage power supply problem.
2) Defect or damage on control board.
D) Amplifier turns on but time delay will not complete; WAIT LED does not turn off.
1) Defect or damage in timing circuitry on control board.
E) Amplifier turns on, time delay completes but amplifier will not transmit.
1) Open T/R control line from transceiver to RELAY jack.
F) Amplifier transmits but red GRID LED often lights.
1) Amplifier overdriven or underloaded; reduce transceiver output and/or increase
amplifier loading.
2) Load VSWR (reflected power) exceeds 200W.
3) Exciter output poorly controlled. External ALC may help.
G) Amplifier operates but green GRID LED will not light and plate current is low; transceiver
does not seem to be able to drive amplifier to its rated RF output power level.
1) External ALC control voltage to transceiver excessive (see section 5.6, ALC Provi
sion).
2) Input rf load resistor or bias circuitry damaged.
3) Possible damaged or defective tube(s).
H) Receive signals disappear or are severely attenuated when switching from STBY to OPR
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