13
Troubleshooting
If your symptoms are not covered below, check the orientation of all components, connectors, and wiring;
look for cold solder joints; and check all DC voltages (see DC Voltage Chart).
Band-pass filter passband not adjustable, or low-pass filter doesn't roll off high-pitch noise:
If there's
a problem with the audio filter, verify that U1 (LM837) is not installed backwards. Also check all
components in the low-pass and band-pass filter sections. Check continuity of L1 and L2.
Clock time doesn't increment:
This probably indicates that U3 is installed backwards or is defective, or
that the 32.768-kHz oscillator is not running. Check X1 and C19.
Clock doesn't keep time with K2 power turned off:
Make sure the battery is installed correctly. (Nothing
will be damaged if the battery is installed backwards, thanks to diode D2.) If you suspect the battery is bad,
measure it with a voltmeter, and replace it if it reads under about 2.5 volts.
Receiver noise heard when in time or date display mode:
This is normal. The main microcontroller polls
the KAF2 for time or date information once per second, waking up all option module processors, which
generates noise that is audible at some frequencies. The K2 does not mute the receiver when date or time is
being displayed, because the operator may want to use WWV or some other on-air time source for clock
setting. If you wish to leave the clock display on for long periods of time, simply turn down the receiver's
volume control or use the squelch menu entry (
S L C H
, in the secondary menu).
Error messages:
If you see
N O T I N S T
or a similar message when you hold
A F I L
or tap
D I S P L A Y
, the
KAF2's microcontroller (U2) may not functioning. Make sure it isn't installed backwards. Also check for
bent pins, check voltages on all pins, etc. Try turning power off and back on.
DC Voltage Chart
Voltages are approximate. Measurements were made under the following conditions: 13.8 V power supply,
K2 turned on, 3 V battery installed,
O F F
audio filter mode in effect, jumpers W1 and W2 removed, and S1
set to
IN
.
Pin
V
Pin
V
Pin
V
Pin
V
Pin
V
Pin
V
Pin
V
U1-1
6.0
U1-8
6.0
U2-1
0
U1-10
6.0
U3-1
6.0
Q1-G
6.0
D1-A
5.5
2
6.0
9
6.0
2
6.0
11
6.0
2
~3
S
6.0
D1-C
5.1
3
6.0
10
6.0
3
0
12
6.0
3
~3
D
6.0
D2-A
3.0
4
~12
11
0
4
6.0
13
5.5
4
0
Q2-G
0
D2-C
5.1
5
6.0
12
6.0
5
0
14
6.0
5
0
S
6.0
6
6.0
13
6.0
6
6.0
15
~3
6
0
D
6.0
U4-I
13.8
7
6.0
14
6.0
7
6.0
16
~3
7
0
Q3-G
0
U4-G
0
8
0
17
0
8
5.1
S
6.0
U4-O
6.0
9
0
18
0
D
6.0
Содержание KAF2
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