Troubleshooting Chart; Diodes; Rit Problem; Sidetone Problems - Heathkit HW-9 User Manual

Page
91
Heathkit
DIODES
To
check
a diode, unsolder one end from
the circuit
board, pull the lead up and
out of the
circuit
board
hole,
and proceed
as follows:
1.
Set the
ohmmeter
to the
R
x 1000
range.
2.
Connect one
of the
ohmmeter
test
leads
to the
lead
at
the
cathode (banded) end
of
the diode.
Connect
the other
test
lead
to
the other diode
lead.
Note
the
meter
reading.
Then
inter-
change
the meter
leads
and
take another
read-
ing.
One
reading should be high
and
the other
low
(at
least 10:1).
If
both readings
are either
high
or low, the diode should be
replaced.
TROUBLESHOOTING CHARTS
The
following
chart
lists
problems
and
possible
causes
of
some
troubles
you might encounter.
If
a
particular part
is
mentioned (Q103
for
example)
as
and/or
wired
correctly.
Also check
for
solder bridge
and poor
connections
in
the
surrounding
area.
It
is
also possible,
on
rare occasions,
for a part to
be
a possible cause,
check
that part
and
other
compo-
faulty
and
require replacement,
nents
connected
to
it
to
see that
they are installed
CONDITION
POSSIBLE
CAUSE
RIT Problem
No
control of
RIT 1.
2.
3.
Q103.Q104.
Diode D1
18.
Broken
wire or
poor connection
to
RIT control or points
D
or
C
on
the
oscillator
board.
S-Meter
and Power
Indicator
Problems
RF
out but
no power
reading, S/Units okay.
1.
Missing jumper
at
W41
5.
2.
D408.
No
S/Units or
power
reading,
Transceiver operates okay.
1.
Q302.
2.
No
9-volt
supply
to
Q302.
3.
Meter
wiring.
No
S/Units reading,
Transceiver operates okay.
1.
D306.
Sidetone
Problems