General Receiver Problems; General Transmitter Problems; Transmit And Receive Problems - Heathkit HW-9 User Manual

Page 92
Heathkit®
General Receiver Problems
No
audio
output,
sidetone present, transmit
okay
but
meter
not
working
in
receive.
No
audio output,
sidetone present, transmits okay,
meter okay
in
receive.
No
audio or sidetone,
meter okay
in
transmit
and
receive.
Weak
or
low audio
on
alt
bands, transmits okay.
Poor receiver
sensitivity.
1.
2.
3.
4.
5.
6.
U301.
AGC
(pin
5 of
U301
)
too high.
AGC
Threshold (R329) misadjusted.
U302, Q301,
D301.D302.
No R1 2
Volts
on D301
.
(Q407,
Q408)
L308
open.
U303, U304.
Shorted cables to Selectivity switch.
U303, U306.
Phone
jack
wiring,
cables shorted
D301
,
D302,
open
L303.
Q301,U301,FL301.
T404
incorrectly
wired
or
shorted
D403, D404, D407.
AGC
(R329) misadjusted.
Q107.
Q301.
General Transmitter Problems
Low
or
no
RF
output
on
all
bands,
receive
and
sidetone okay.
I
1.
CW
Level control wiring.
2.
Low
or
no
TX
Out from
BFO
(see
"BFO
Problems").
3.
D401.D402,
L421.
4.
Q401 through Q406.
No RF
output or sidetone,
receive okay.
1.
Q408.
2.
No
T1 2
volt
supply.
3.
Wiring
at
Key
jack or
T/R
board.
4.
Broken
lead
in
key
cable.
Transmit and Receive Problems
No
transmit or receive
on any band, sidetone okay.
1.
9-volt supply,
U402.
2.
Antenna
or
cable connection.
I
3.
Bandswitch wafer
misaligned.
4.
No
HFO
output
(See
"HFO
Problems").
5.
Q10t,Q107.
6.
No
BFO
output
(See
"BFO
Problems").
7.
Mixer
filters.
No
transmit or receive
-
one
band.
I
1
.
HFO
oscillator,
mixer
filter.
2.
Band
switch or
switched
9-volt
supply
to oscillator.
I
3.
Bandpass
filter
misaligned.