DRAKE R8A - Troubleshooting; R8 A Special Display Messages

TROUBLESHOOTING
Symptom
No front panel display or lights
when power is depressed
Scrambled front panel display
when power is depressed
No signals heard when antenna
is connected or sensitivity low
S$ meter indication, but remains
constant
S meter indication, but no sound
heard
SSB signals have excessively
high or low frequency response
No front panel operation i.e.
tuning, frequency entry, etc.
Timer does not operate
Direct frequency entry will not work
R8A Special Display Messages
Probable Cause
A) Power connection
B) Blown supply fuse
A) Microprocessor malfunction
A) Squelch enabled
B) Incorrect antenna input selected
C) RF ATTN enabled
D) RF gain improperly set
A) RF gain improperly set
A) Improper mode selected
B) External speaker selected
C) Squelch enabled
A) PASSBAND OFFSET improperly set
A) Lock enabled
A) Timer not properly set
B) Alternate clock selected
A) Alternate button functions enabled
i.e.) is displayed
Troubleshooting 38
Corrective Action
A) Check power supply cables
B) Check fuse
C) Contact service
A) Unplug from power source and re-
connect to reset microprocessor
A) Tum squelch counterclockwise
B) Select correct antenna input
C) Turn off RF ATTN
D) Turn RF gain clockwise
A) Turn RF gain clockwise
A) Check mode selection
B) Check external speaker switch on
rear panel
A) Center PASSBAND OFFSET control
A) Press [Eel “LOCK” to unlock front
panel
A) Program timer ON/OFF times
A) Press [ * | for confirmation beep
and annunciator not displayed
"PWRLOS" or "PWRLOS” (power lost) indicates that power
has been disrupted to the receiver and the clocks have
lost their time settings. There is no problem with the
receiver, anditmay be operated as normal. To extinguish
this message, simply reset the clocks.
"PWRFAIL" (Power Fail) indicates that the power supplied
tothe receiver does not meetthe specified requirements.
This could be caused by an improperly selected AC line
voltage, low AC line voltage (brown out), or low DC
voltage. Normal operations of the receiver are halted in
the "PWRFAIL" mode. To return to normal operation,
disconnect the receiver from the power source, Make
sure the proper AC Voltage range is selected from the
rear panel switch, then reconnect the power.
Continued "PWRFAIL" messages under a known good
powersource couldindicate receiver power supply prob-
lems, Should this occur, contact the Service Department.
"UNLOCKD" (unlocked) indicates that the synthesizer of
the phased locked loop circuit is not locking to the proper
frequency. If this should occur with the receiver, contact
the Service Department with details on what operations
are affected.