430/440 MHz FM TRANSCEIVER
TH-41A
TH-41BT
TH-41E
220 MHz FM TRANSCEIVER
TH-31A
TH-31BT
144 MHz FM TRANSCEIVER
TH-21A
TH-21BT
TH-21E
INSTRUCTION MANUAL
KENWOOD CORPORATION
©PRINTED IN JAPAN B50-8132-00(K,M,W)(G)
87/12 11 10 987654321 86/12 11 10 9
Before operation
• Ensure the supplied whip
antenna is securely tight
ened.
• The trimmers and cores in
side the unit are factory ad
justed. Do not touch them.
• Should the unit require ser
vice, contact your author
ized dealer.
This Instruction Manual covers the following models:
Illustrations show the TH-41 BT.
TH-41A 430/440 MHz FM transceiver
TH-41 BT 430/440 MHz FM transceiver with DTMF
TH-41 E 430/440 MHz FM transceiver with 1750 Hz tone
TH-31A 220 MHz FM transceiver
TH-31 BT 220 MHz FM transceiver with DTMF
TH-21A 144 MHz FM transceiver
TH-21 BT 144 MHz FM transceiver with DTMF
TH-21 E 144 MHz FM transceiver with 1 750 Hz tone
Contents
1.
Accessories............................................................................................................. 3
Specifications.......................................................................................................... 4
2.
Battery notes........................................................................................................... 5
3.
Controls and their functions.................................................................................. 6
4.
Operation............................................................................................................... 10
5.
5-1. Reception....................................................................................................... 10
5-2. Transmission................................................................................................. 10
5-3. DTMF key pad operation............................................................................... 10
Optional accessories........................................................................................... 11
6.
7.
Block Diagram...................................................................................................... 11
1. Accessories
Confirm that the accessories shown below are included.
Whip antenna................................................................................................................. 1
Ni-Cd battery pack......................................................................................................... 1
Battery charger.............................................................................................................. 1
Earphone (TH-41A/41 BT/31A/31 BT/21A/21 BT)........................................................ 1
Hand strap...................................................................................................................... 1
Instruction Manual......................................................................................................... 1
Warranty card (For users in USA only)............................................................. 1
The carton box and packing materials should be retained for future tran
sportation.
Note:
The TH-31A/31BT does not operate above 224.995 MHz, since
this is the upper limit of the 220 MHz band.
Attempting to operate above this frequency will not produce any re
ceive or transmit functions.
Remember the radio is designed to operate from 220.000 MHz thru
and including 224.995 MHz only.
2. Specifications
TH-41A/41BT/41E
430MHz
version
General
Frequency range 430MHz
Signal type F3 (FM)
Operating tempera
ture
Antenna impedance
Power supply voltage
Power consumption At reception standby; Less than 30 mA
Dimensions
Weight
Transmitter section
Output power Hi; 1.0W, Low; approx. 1 50 mW
Modulation system
Max. frequency de
viation
Unwanted reflection Less than -60 dB
Microphone
Receiver section
Reception system
Intermediate fre
quency
Sensitivity
Squelch sensitivity
Selectivity
AF output
to
440MHz
-20X ~ +50°C
50i3
5.8V - 10.OV (rating voltage; 7.2V)
At transmission (Hi); Less than 650 mA
W 57 (65.5) X H 120 (127.5) x D 28 (32) mm
The numbers in the parenthesis include projections.
Approx. 290 g (including antenna and Ni-Cd batteries)
Reactance modulation
±5 kHz
Condenser type
Double superheterodyne
1st: 21.6MHz
2nd: 455kHz
S/N more than 26 dB
at -6dB// (0.5 ^V) input
12 dB SINAD; less than -1 2 dB/i (0.25 //V)
Less than 0.2^V
-6 dB at more than 12 kHz
-40 dB at less than 28 kHz
More than 250 mW (8Q load, distortion 10%)
440MHz
version
440MHz
to
450MHz
(Low); About 350 mA
TH-31A/
31 BT
220MHz
to
225MHz
1 St:
16.9MHz
2nd:
455kHz
S/N more than 28dB at-6dB|t/
(0.5/c/V) input
'’^^0^2^V 1 0.25//V
TH-21A/
21 BT
144MHz
to
148MHz
Less than 28 mA
Less than 600 mA
About 300 mA
1st: 16.3MHz
2nd: 455kHz
TH-21E
144MHz
146MHz
to
Design and specifications subject to change without notice.
3. Battery notes
3.1. Recharging the battery pack
• Plug the BC-3 into the AC line outlet and interconnect the adapter to
the battery pack PB-21. At this time, be sure the polarities. While re
charging is correctly in progress, the red LED on the BC-3 lights.
However, the LED remains lits while the BC-3 is still connected to the
AC line outlet. Therefore, unplug the BC-3 after 8 hours of recharging.
Notes:
1. Recharging should be done within ambient temperature between
10°C and 40°C. Recharging performed out of this range may not
fully charge the battery pack.
2. Excessive charging, if happened, the battery performance and its
life may lessen.
• Align the grooves in the bat
tery case and unit and slide
in the battery case to the
right. Slide to the left to re
move the battery case.
3.2. Operation time with AAA batteries
The operation time with a repeated 1 minute TX and 3 minute RX cy
cle is approximately 40 minutes with manganese batteries and about
90 minutes with alkaline manganese batteries.
To communicate over a short distance, set the Hi/Low switch to
I LOW I to conserve power and thus extend operation time. When the
batteries are exhausted and the [ON AIR| indicator lights dimly, replace
the batteries with new ones.
5
4. Controls and their functions
VOL control (Volume control/power switch)
• This knob is dual-purpose; power switch and volume control.
• When this knob is turned clockwise, power is supplied.
• When this knob is further rotated, the volume level increases.
MIC jack (Microphone Jack)
(D
• Used in combination with the SP jack, for connection of the op
tional speaker/microphone (SMC-30) or headset with VOX
(HMC-1).
Do not use other microphones other than the SMC-30 and the
HMC-1, or damage of the transceiver may result. (Because of DC
voltage is present at the plug.)
• When the plug is inserted in this jack, the built-in microphone is
automatically disconnected.
SP jack (Speaker jack)
(3)
• Connect an external speaker or earphone.
• Used with the MIC jack, for optional SMC-30 or HMC-1.
• When the plug is inserted in this jack, the built-in speaker is auto
matically disconnected.
Antenna connector
0
• Insert the supplied helical antenna and rotate to the right to se
cure.
(D Tone switch
• Activates the sub tone (TH-41 BT/31 BT/21 BT).
• Tone unit is the optional TU-6 (TH-41 A/31A/21 A).
• Activates 1 750 Hz tone (TH-41 E/21 E).
(D +5 kHz switch
• When the switch is ON the operating frequency is 5 kHz higher
than indicated by the thumb wheel switches.
0
Frequency setting switches (Thumb wheel switches)
A
....
Used to set to 1 MHz.
B
....
Used to set to 100 kHz.
C
....
Used to set to 10 kHz.
0 ON AIR indicator
• Lights for transmission.
• When this indicator lights dimly, replace the batteries with new
ones.
0 SQ control (Squelch control)
• Used to eliminate noise at non-signal condition. For normal opera
tion, turn the knob clockwise to the point at which noise just dis
appears.
(3B) PTT switch (Press-To-Talk switch)
• Press this switch and speak into the micro phone for transmission.
• The microphone is built in the same place as the speaker.
0 Hi/Low switch
• Used to adjust the transmission output.
• At Hi position, the output power is 1 W. At Low position, the out
put power is about 1 50 mW.
TX offset switch
TH-41A/41BT "S" Transmit and rec eive frequency are the
same. (Also known as "Simplex".)
"+" Transmit frequency is 5 MHz higher than
the receive frequency.
Transmit frequency is 5 MHz lower than
the receive frequency.
TH-41E Shifts the transmit frequency for repeater operation.
"S" Simplex (receive and transmit frequencies
are the same).
"D - A" Sets the transmit frequency 7.6 MHz lower
than the frequency set by the thumb wheel
switches.
"D - B" Switches the transmit frequency down 1.6
MHz from the receive frequency.
TH-31A/31 BT
TH-21A/21BT
TH-21E
Shifts the transmit frequency for repeater operation.
"S" Simplex (receive and transmit frequencies
are the same).
"REV" Sets the receive frequency 1.6 MHz lower
than the frequency set by the thumb wheel
switches.
Switches the transmit frequency down 1.6
MHz from the receive frequency.
"+" Transmit frequency is 600 kHz higher than
the receive frequency.
Transmit frequency is 600 kHz lower than
the receive frequency.
"S" Transmit and receive frequency are the
same. (Also known as "Simplex".)
Shifts the transmit frequency for repeater operation.
"S" Simplex (receive and transmit frequencies
are the same).
"REV" Sets the receive frequency 600 kHz lower
than the frequency set by the thumb wheel
siwtches.
"-" Switches the transmit frequency down
600 kHz from the recieve frequency.
Tone frequency setting switches (6P dip switches) (TH-41BT/
31BT/21BT)
Tone frequency setting table
Tone ON..
frequency
1
2 71.9
3 74.4
4
5
6 82.5
7 85.4
8 88.5 0
9
10 94.8 0
11 100.0
12
;13
14
15 114.8
16 118.8
17
18 127.3
19 131.8
20 136.5 0 1 1 1
67.0 0 0 0 000 21
77.0 0 0 0
79.7
91.5
103.5 001 1 1 0 32
107.2
110.9
123.0 0 1
1, OFF..
1
234
0
0 0 0
0 0
010
0
010 0
0 0 011
1
0 0
0 0
0 1 0
010 1
0 0 101
1
0 0
010 0 1 0
0 1 0 0 1
010
0 1 1
1 1
0
1 1 0
0
.0
5 6 frequency
1 0 22
0 23 151.4 1
1 24
1
0
0 25
0
26
1 0 0
1 1 1
0 0
1 1
1
0 1
27
28
0 29
0 30
1
31 203.5 1 1
1
33 218.1 1 1 0 1 1
34
1
35
1 0
36
1
37
0
1
1
1 0
Tone ON.. 1, OFF.
1
2 345
141.3 0
146.2 1 0 0 0 1 0
156.7
162.2 1
167.9 1 0
173.8 1 0
179.9 1 0
186.2 101 1
192.8
210.7 1 101
225.7 111 0 1
233.6 1
241.8 111 1 1
250.3 1 1 1 1
1 111
0 0 0 1 1
0 0
1
1
1
0 0 1 1
1 1
1
1 0
1 1
010
1 1
0
1 1
1 1
1
1 1
0
1 1
1 0 0
110 0 1 0
.0
6
1
1
0
0
1
0
0
5. Operation
5.1. Reception
(1 ) Turn the VOL control to the right to supply power, and adjust the vo
lume control to the desired level.
(2) Adjust the squelch control clockwise until the background noise just
quiets.
(3) Adjust the frequency switches to the desired receive frequency.
5.2. Transmission
( 1 ) Select the desired transmit offset.
(2) Check to see that the frequency is not busy.
(3) Press the PTT switch and speak into the microphone. The ON AIR in
dicator will light.
Note: The distance between the microphone and your mouth is 5
-10 cm.
5.3. DTMF key pad operation (TH-41BT/31BT/21BT only)
(1) To operate the keyboard as a DTMF key pad press the PTT switch
and dial the desired number.
(2) After the first number has been entered the radio will remain keyed
for approximately 1.5 seconds, thus allowing the release of the PTT
switch.
1 0
6. Optional accessories
The following optional accessories are available for the TH-41/31/21
series.
(1 ) Rechargeable Ni-Cd battery pack............................................................ PB-21
(2) Heavy Duty Ni-Cd rechargeable battery
(3) Quick battery charger
(4) Manganese battery case
(5) SUM-2 battery case (for extended operation)
(6) DC-DC power supply (for mobile operation)............................................ DC-21
(7) External speaker/microphone
(8) Headset with VOX...................................................................................... HMC-1
(9) Soft carrying case.......................................................................................... SC-8
(10) Earphone........................................................................................................ HS-8
(11 ) Antenna conversion plug (twist lock to BNC)
(12) Tone unit........................................................................................................ TU-6
....................................................................................
................................................................................
..................................................................
................................................
.............................................
............................................
PB-21 H
BC-6
BT-2
EB-2
SMC-30
AJ-3
7. Block Diagram
(1 ) Block Diagram(TH-41 A/41 BT/41 E)
1 1
(2) Block Diagram(TH-31A/31 ВТ)
(3) Block Diagram(TH-21A/21BT/21E)
ANT
220-225 MHz
1 2
KENWOOD CORPORATION
Shionogi Shibuya Building. I7-5, 2*chome Shtbuya. Shibuya-hu. Tokyo 150. Japan
TRtO-KENWOOO COMMUNICATIONS
Post Otttce Boi 7065, Compton,California 90224,U SA
KENWOOD COMMUNICATIONS
DIVISION OF KENWOOD ELECTRONICS DEUTSCHLAND GMBH
Remtxucker Str 15. 6056 Heusenstamm. West Germany
KENWOOD ELECTRONICS BENELUX NV
Leuvensesteenweg 504,8-1930 Zaventem. BeKHcri
KENWOOD ELECTRONICS AUSTRALIA PTY LTD.
4£ Woodcock Place. Lane Cove. NSW 2066. Australia
KENWOOD
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