Adjustment - Kenwood TK-780 Service Manual

Test Mode
Test Mode Operating Features
This transceiver has a test mode. To enter test mode,
press [B] key and turn power on. Hold [B] key until test
channel No. and test signalling No. appears on LCD.
Test mode can be inhibited by programming. To exit test
mode, switch the power on again. The following functions
are available in test mode.
• Controls ("SFT" appears)
[PTT] Used when making a transmission.
[ ] Shift off.
[A] FFSK 1200 bps and 2400 bps.
[B] Shift off.
[C] Compander function on and off.
[D] Beat shift on and off.
[CALL] Shift off.
[Channel Up/Down] Shift off.
[Volume Up/Down] Shift off.
• Controls ("SFT" not appears)
[PTT] Used when making a transmission.
[ ] Monitor on and off.
[A] Sets to the tuning mode.
[B] Shift on.
[C] RF power high and low.
[D] Changes signalling.
[CALL] Changes wide, semi-wide and nar-
row
[Channel Up/Down] Changes channel.
[Volume Up/Down] Volume up/down.
Note : If a [A], [B], [C], [D] key is pressed during transmis-
sion, the DTMF corresponding to the key that was pressed
is sent.
• LCD indicator
"SCN" Unused
" " Lights at compander on.
"AUX" Unused.
"P" Lights at RF power low.
"MON" Lights at monitor on.
"SVC" Unused.
" " Lights at FFSK 2400 bps.
• LED indicator
Red LED Lights during transmission.
Green LED Lights when there is a carrier.
• Sub LCD indicator
"SFT" Appears at shift on.

ADJUSTMENT

Frequency and Signalling
The set has been adjusted for the frequencies shown in
the following table. When required, re-adjust them follow-
ing the adjustment procedure to obtain the frequencies you
want in actual operation.
• Frequency (MHz)
Channel No.
1
2
3
4
5
6
7~16
• Signalling
Signalling No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Preparations for Tuning the Transceiver
Before attempting to tune the transceiver, connect the
unit to a suitable power supply.
Whenever the transmitter is turned, the unit must be
connected to a suitable dummy load (i.e. power meter).
The speaker output connector must be terminated with a
4Ω dummy load and connected to an AC voltmeter and an
audio distortion meter or a SINAD measurement meter at all
times during tuning.
Transceiver Tuning
(To place transceiver in tuning mode)
Channel appears on LCD. Set channel according to tun-
ing requirements.
LCD display (Test mode)
E,E3
RX TX
160.05000 160.10000
146.05000 146.10000
173.95000 173.90000
160.00000 160.00000
160.20000 160.20000
160.40000 160.40000
– –
RX
None None
None 100Hz square
QT 67.0Hz QT 67.0Hz
QT 151.4Hz QT 151.4Hz
QT 210.7Hz QT 210.7Hz
QT 250.3Hz QT 250.3Hz
DQT 023N DQT 023N
DQT 754I DQT 754I
DTMF DEC, (159D) DTMF ENC, (159D)
None DTMF tone 9
2-tone (321.7/928.1Hz) None
Single tone 1200Hz Single tone 1200Hz
5-tone DEC. (EIA #12345) 5-tone ENC. (EIA #12345)
None FFSK
FFSK code FFSK code
–
n 1 1
W/SW/N Channel No. Signalling No.
TK-780
TX
45