34
TK-480/481
ADJUSTMENT
Test Mode■ Test mode operating features
This transceiver has a test mode.
To enter test mode,
press [A] key and turn power on. Hold [A] 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 avail-
able in test mode.
•Controls
Controls “FCN” appears “FCN” not appears
[PTT] Used when making a Used when making
transmission. a transmission.
[AUX] Unused Unused.
[MON] Monitor ON and OFF. Monitor ON and OFF.
[LAMP] Lights the lamp for five Unused.
seconds.
Lighting is extended for
a further five seconds by
pressing any key while
the lamp is lit.
[S] MSK 1200 bps and Sets to the Tuning
2400 bps mode.
[A] Function OFF Function ON.
[B] Compander function RF power HIGH and
ON and OFF. LOW.
[C] Beat shift ON and OFF Changes group.
[0] to [9], Used as the DTMF Used as the DTMF
and [#], keypad. If a key is keypad. If a key is
[*] pressed during trans- pressed during trans-
mission, the DTMF mission, the DTMF
corresponding to the corresponding to the
key that was pressed key that was pressed
is sent. (keypad model) is sent. (keypad model)
[ENCODER]
Changes system. Changes system.
Note : If a [S], [A], [B], [C] 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.
“LO”Lights at RF Power Low.
“P”Unused
“MON”Lights at moniter ON.
“SVC”Unused
“”Lights at MSK 2400 bps.
•LED indicator
Red LED Lights during transmission. Blinks at the
low battery voltage warning.
Green LED Lights when there is a carrier.
•Sub LCD indicator
“FCN”Appears at Function ON.
■Frequency and signalling
The set has been adjusted for the frequencies shown in
the following table. When required. re-adjust them following
the adjustment procedure to obtain the frequencies you
want in actual operation.
Frequency (MHz)
SYS No. TK-480 TK-481
RX (TX : TA) TX RX (TX : TA) TX
1 851.0500 806.0500 935.0250 896.0250
2 851.5500 806.5500 935.0500 896.0500
3 860.0000 815.0000 938.0000 899.0000
4 860.5000 815.5000 938.0250 899.0250
5 865.9875 820.9875 939.9875 900.9875
6 869.4000 824.4000 940.4000 901.4000
7 869.9000 824.9000 940.9000 901.9000
8 855.4000 810.4000 936.2500 897.2500
9 865.6000 820.6000 939.3000 900.3000
10 867.5000 822.5000 936.7500 897.7500
11~16 ––––
Signalling
Group No. RX TX
1 None None
2 None 100Hz square
3 LTR data LTR data
4 QT 67.0Hz QT 67.0Hz
5 QT 151.4Hz QT 151.4Hz
6 QT 210.7Hz QT 210.7Hz
7 QT 250.3Hz QT 250.3Hz
8 DQT D023N DQT D023N
9 DQT D754I DQT D754I
10 DTMF DEC, (159D) DTMF DEC, (159D)
11 None DTMF tone 9
12 None None
13 Single tone 1200Hz Single tone 1200Hz
14 None MSK
15 MSK code MSK code
•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
16Ω dummy load and connected to an AC voltmeter and an
audio distortion meter or a SINAD measurement meter at all
times during tuning.