Kenwood TH-27A User manual

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Z
o
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o
144 MHz FM TRANSCEIVER
TH-27A/27E
430/440MHz FM TRANSCEI VER
TH-47A/47E
INSTRUCTION MANUAL
KENWOOD CORPORATION
© PRINTED IN JAPAN 862-0046-00(A.T)(K.X.T)
91 / 12111098765432190/1211109876

CAUTION
THE MEMORY IS MAINTAINED BY A RECHARGEABLE
SECONDARY LITHIUM BATTERY. WITH THE BATTERY
CASE REMOVED, THE MEMORY IS RESET TO ITS INI-
TIAL STATE AFTER ABOUT 20 DAYS. A FULLY DIS-
CHARGED BATTERY WILL REQUIRE APPROX . 10
HOURS TO REACH FULL CHARGE AFTER INSTALLING
A NiCd BATTERY PACK OR AN EXTERNAL POWER
SUPPLY.
FCCWARNING
Press the powe r
switch for l on ger
than 0.3 second
to turn the tran s-
ceiver on or off .
This
equipment may generate or use radio frequency
energy . Changes or modifications to this equipment
may cause harmful interference unless the mod ifica-
tions are expressly approved in the instruction man-
ual. The user could lose
the authority to operate this
equipment if an unauthorized change or modification
is made.
2
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CONTENTS
1. BEFORE OPERATION .............................................. 4
2. SPECIFICATIONS and ACCESSORIES ................. 4
3. BATTERY PACK ................ ........................... 6
4. OPERATION .............................................................. 8
4-1 OPERATING CONTROLS ............................. 8
4-2
RECEIVER OPERATION ................................ 15
Receiver Operation
Frequency Selection
Step
Size selection
Programmable VFO Tuning Limits
4-3 TRANSMITTER OPERATION .......
18
4-4 MEMORy....... ...................................... 19
Microprocessor Memory Back-up
Microprocessor Initialization
Memory Channel
Memory Contents
Memory Entry
Memory Channel Re call
Memory Shift
4-5 SCAN ................................... 23
Scan Options
Hold/Resume Programming
Band Scan
Programmable
Ba nd Scan
MHz Scan
Memory Channel Scan
VFO/Memory Channel Scan
CALL Scan
Memory Channel Lockout
Pr ior ity Alert Function
4-6 REPEATER OPERATION ...............................
28
Transmitter Offset
Reverse Function
Tone and CTCSS Operation
Autopatch Operations
4-7 DTMF MEMORy ......................................... 31
4-8 DTSS ................................................................ 33
DTSS Code
D
TSS Code Selection
Us ing the DTSS function
Us ing DTSS with a Repeater
4-9 PAGING .
... ............................................... ... .... 35
Paging Code Memories
Setting the
Pag ing Codes
Paging Transmission (Calling)
Paging Reception (Wait)
Code Lockout
4 -10 TONE ALERT SYSTEM ................................. 41
4-11 BATTERY SAVER ........................................... 42
4 -1 2 AUTOMATIC POWER OFF .......................... 42
4 -13 CLOCK ............................................................ 43
5. 8LOCK DIAGRAM and SCHEMATIC DIAGRAM
..... ................................................... another sheet
6. MAINTENANCE .......................................................
46
In Case of Difficulty
7. OPTIONAL ACCESSORIES .................................... 48
3

1. BEFORE OPERATION
Thank you for pur ch as ing th is new transceiver .
IMPORTANT
Please read this instruction manual carefully before
placing your transceiver in service.
CAUTION
Long transmission or extended operation in the HI
power mode mi ght cause the rear of this transceiver
to get warm . Do not place the transceiver where the
heat sink ( rear panel) mi ght come in contact with
pla st ic or vinyl surfaces.
Use of an external antenna for fixed station is
recommended.
SAVE THIS INSTRUCTION MANUAL.
Th is Instruction Manual covers the following mode ls:
TH-27A: 144MHz FM transceiver
TH-27E:
144MHz FM trans ceiv er
(U.K.and European version)
TH-47
A: 440MHz FM transceiver
( U.S.A. and Canadian version)
TH-47A: 430MHz FM transceiver (Other market)
TH-
47E : 430MHz FM transceiver
(U.K.and European version)
The following explicit definitions apply in this manual:
NOTE If d isr egarded. inconvenience only. no risk of equi pment
damage or personal i njury_
CAUTION Equ ipment damage may occur, but not personal inju ry.
4
2. S PECIFICATIONS and
ACCESSORIES
2-1. SPECIFICATIONS
GENERAL TH-27A1E TH·47AJE
U.S.A. VerSion 144 to 148 4 3B to 450
FREQUENCY U.K.and Europe
144t0146 430 to 440
RANGE (MHz)
Other market
430 to 440
144t0148
or 438 to 450
MODE F3E (FM)
ANTENNA IM PEDANCE 50 Q
OPERATING TEMPERATURE 20°C -+ 60°C ( 4
°F-14 0 °F)
POWER I DC IN(nom,nal) 7.2 v-16 VDC (13.B VDC)
REQUIREMENTS I BATTERY PACK 6.3 V -
16 VDC (7 .2VDC)
CURRENT DRAIN
13.8VDC (Ext. Power Supply) H
Approx. 1.SA Approx. 1.SA
7 2VDC (Battery) H
Approx.1A Approx.1A
Transmit mode L
Approx O.SA
Approx.O.SA
Transmit mode EL
Approx. 0,' 2A App
r
ox.O.1SA
Receive mode With no signal
Approx.60mA Approx.6SmA
Battery Save mode
Approx 17mA
Approx. 17mA
GROUND Negative
DIMEN510N(W x H x D) 49.5x 124.7x38.0mm
DIMENSION( Projection Included) 57x138.7x39.7mm
WEIGHT
360
9
MICROPHONE INPEDANCE
2kQ
TRANSMITTER
H (13 8VDC) more than SW
OUTPUT H (7.2VDC) Approx. 2.5W TApprox. 1.SW
POWER L Approx.O.SW
EL Approx.20mW

TH·27A1E TH·47A1E
MODULATION
Reactance
MAXIMUM FREQUENCY DEVIATION + 5kHz
SPURIOUS RADIATION less than 60dB
RECEIVER
double converSIon super-
CIRCUITRY heterodyne
INTERMEDIATE FREQUENCY 1 st IF
45.05 MHz S8.525 MHz
INTERMEDIATE FREQUENCY 2 nd IF 455 kHz
less than
less than
SENSITIVITY (1 2dB SINAD) - 1
6dB~ - 1 SdB~
(0.l6uV)
(0.18u V)
SQUELCH SENSITIVITY less than 20dBu(0.1
~V)
SELECTIVITY - 6dB morethan 12kHz
SELECTIVITY -
60dB less than 28kHz
AUDIO OUTPUT POWER more than 200 mW
(10% distortion)
(across aQ load)
NOTES:
1. Circuits and rating are subject to change without notice. due to
development in technology. . . .
2. Recommended duty cycle: 1 minute Transmission. 3 minutes
Reception.
2-2. ACCESSORIES
Unpack your transceiver carefully and confirm that the
accessories listed
below are included in the box.
Antenna (TH-27
N27E) T90-0420·x X 1
(TH-47N47E) T90-0421-x x 1
Belt Hook .................................... J29-0459-04 ......... 1
Hand Strap ..................................
J69-0312-04 ..... .. .. 1
Rubber Cap ..................................
B09·0324-03 ........ 1
NiCd Battery Pack(PB-13) ........
W09-0563-05 ....... 1
Battery Charger(BC·1
4) .... .................................. 1
for U.S.A. and Canadian version
(1 20V)
W09-0565-x X
for European version
(220V) W09-0569-X X
for U.K.version
(240V) W09-0568- x X
for Oceania.version
(240V) W09-0567-x X
for other market (120/240V) W09·0566 -x X
Instruction Manual B62·0046-XX 1 copy
Warranty Card .................................................................. 1
(U.S.A
.. Canada.and European version only)
After unpacking
Shipping container:
Save the boxes and
packing in the event
your unit needs
to be
transported for re-
mote operation. main-
tenance. or service. !;P ~
Hand Strap
t
~~
Belt Hook 5

3. BATTERY PACK
• Ni-Cd BATTERY PACK (PB-13)
This battery pack has not been charged at the factory in
order to provide you with the greatest number of
charge/discharge cycles. You must charge the battery
before use. The battery pack will require several
charge/discharge cycles before you can expect to see
the maximum operating period between charges. If the
battery will be stored for greater than 2 months it should
be recharged before use.
• RECHARGING
Insert the charge plug from the charger (BC-' 4) i nto the
receptacle on the top of the transceiver. Then plug the
charger
into the AC line. Do not allow the battery to
charge for greater than' 5 hours. The use for life and
battery performance will be reduced
if you exceed the
recommended charge period.
(Illustrations show the U.S.A. version.)
6
NOTE
Recharging should be done within an ambient
temperature between SoC - 40 °C (41 °F - 104 ° F).
Reharging performed out of this range may not fully
charge the battery.
• INSTALLING THE BATTERY PACK
Insert the battery pack i nto the transceiver unt il it locks
in place.
To remove the battery pack slide the Release button and
pull the pack.
RELEASE button

• BATTERY VOLTAGE LEVEL METER
The meter indicates the relative battery voltage during
transmit.
Recharge
or replace the batteries when the level reaches
the
low indicator. NiCd Battery pack
Fully charged Fully discharged
Approximate battery condition
• OPERATING TIME
H M L EL
PB·13 2 2.5 4 15
TH·27A
TH·27E
Alkaline B.
--0.8 5.5
Manganese B. 2 2 3 6.5
PB·13 2 2.5 4 13.5
TH·47A
TH·47E
Alkaline B. - - 0.8 4.5
Manganese B. 2 2.5 3 6
• 1 minute transmission. 3 minutes reception, AF output
0.2 W/8 11.
• Battery saver function on.
CAUTION
The display indicator flashes and the POWER switch
will not work when the battery starts to go flat.
When this happens, recharge or replace the battery.
We recommend use of the NiCd battery pack for long
transmission or extended operation.
Manganese
ba tteries (except Alkaline manganese batter-
ies) is available for Low or EL position.
• MANGANESE or ALKALINE BATTERIES
Load 6 x R6 (AA) manganese or alkaline batteries in
series
in the optional battery case(BT·8). (Be sure to
observe the polarities.)
(We recommend use of high perfomance manganese
batteries.)
Be sure the pack and transceiver are locked together.
Manganese
or Alkaline batteries
New batteries
r::::: -_-:::. " -
-
~
-
•
Need to change batteries
Approximate battery condition
7

4. OPERATION
4·1. OPERATING CONTROLS
<D Antenna connector
Connect the antenna that
is supplied to this connector.
Twist to lock.
® DC IN terminal
This terminal
is used for an external power supply. Input
voltage is 1 3.a VDC nominal. The center is the + side
and the sleeve
is the -side.
NOTE
You should turn the power switch OFF when connect-
ing a power source to this terminal. Pay close atten-
tion to polarity.
Use the KENWOOD PG-2W or PG-3F optional cable for
connection.
@ MIC jack
This jack
is used for connection of an external micro-
phone. The use of an electret type microphone is
recommended. Input impedance is 2kn and the DC
voltage on this terminal is Approx. 4 V (MAX 3.5 mAl.
a
NOTE
The use of a dynamic microphone is not recommend-
ed.
Speaker
..
SP , V D
"' 0#12 .5
Ground Plug ;;
w
...
,
~
5V
,
~
5 V ! V ] .~
MIC
•
MIC
1\
>-
u
>-
:>
PTT ,
10 ~F
PTT
~
w
@ SP jack
This jack
is used to connect an external speaker or
earphone. The recommended impedance
is an.
@ ON AIR indicator
On whenever the transceiver is in the transmit mode.
@ VOL control
Rotating the control further clockwise will increase the
volume.
(J) SQL(Squelch) control
This control
is used to select the desired Squelch
threshold level.
® Tuning control
This control
is used to select the desired transmitter
/receiver frequency, M
Hz step, Memory Channel. Fre-
quency Step, Tone Frequency, Scan Direction, etc.

ill MONI switch
m rnrnco ·
mmrnrn .
CDcTICDam<
~rn~;nB .
,. ,...,,,.,,,.,,,
,.,../
When operating in the CTCSS (Tone Squelch) mode you
can use this key to determine
if the frequency is in use
before transmitting. Pressing this key will disable the
CTCSS function as long as the key is held depressed.
~ PTT (Push To Talk) switch
Press this switch whenever you wish to transmit.
@ POWER switch .
Press for longer than 0.3 second to turn the transceiver
ON or OFF.
@ LAMP key
This switch
is used to control the night lamp on the LCD
display. The lamp will turn itself OFF automatically 5
seconds after the last key operation.
Pressing the key within 10 seconds of pressing the Fkey
will light the lamp on the LCD display until pressing this
key again.
@ TONEITONE SEL key
Except European version; This key
is used to activate the
subaudible tone encoder.
European version; This key
is used to transmit the
1750Hz repeater access tone whenever this key is
depressed.
U.S.A .. Canada. or with optional TSU-7; Pressing the key
within 10 seconds of pressing the F key will switch to
the tone frequency selection mode. The Tuning control
can then
be used to select the desired tone frequency.
@ CALVC. SCAN key
Press this key to activate the call channel function.
Pressing the key within 10 seconds of pressing the Fkey
will start or stop CALL channel scanning.
(/) DTSS/PAG key
This key
is used to activate the DTSS function.
Pressing the key within 10 seconds of pressing the Fkey
will turn the PAGING function on or off.
@ LOW/CLOCK key
This key
is used to switch the transmit output power;
M
edi um(M)/Low(L)/Econom ic· Low(E L)/H igh (no
indicator).
9

Pressing the key within 10 seconds of pressing the Fkey
will switch alternately between the frequency displayand
CLOCK display.
~ " ~ CTCSS T" T 'J ,
b ffi Ci!J mA
PROG-l PROG - 2 MEMO TX 5
,F~~
<D l/AL key
This key
is used to turn memory channell on or off.
Pressing the key
within 10 seconds of pressing the Fkey
will check Memory Channel 1 at approx. 5 second
intervals.
If the channel is busy, a beep will sound
(ALERT).
® 2/CTCSS key
This key is used
to turn memory channel 2 on or off.
Pressing the key
within 10 seconds of pressing the Fkey
will turn the CTCSS function on or off.
@ 3/T.AL T key
This key
is used to turn memory channel 3 on or off.
Pressing the key
within 10 seconds of pressing the Fkey
will turn the TONE ALERT function on or off.
10
@ F key
This key
is used to activate control of the functions. The
"F" indicator will turn ON or flash for approximately 10
seconds. You must press the desired function key before
the indicator turns off.
® 4/ PROG-1 key
This key
is used to turn memory channel 4 on or off.
Pressing the key
within 10 seconds of pressing the Fkey
will select the programmable scan 1 MODE.
@ 5/ PROG-2 key
This key
is used to turn memory channel 5 on or off.
Pressing the key within
10 seconds of pressing the Fkey
will select the programmable scan 2 MODE.
(f) 6/ MEMO key
This key
is used to turn memory channel 6 on or off.
Pressing the key
within 10 seconds of pressing the F key
will select the memory scan MODE.
@ M/ TX.S key
This key
is used to store the displayed data into memory.
Pressing the key within
10 seconds of pressing the Fkey
will turn the TX.STOP function on Or off.

~~
TI~E ~OCK
CH QNT C
4
REV L. OUT 5 rEP ... ~ , SCAN
rr~~
CD 7/SEEK key
This key
is used to turn memory channel 7 on or off.
Pressing the key within 10 seconds of pressing the Fkey
will select SEEK operated scan.
® 8/CAR key
This key
is used to turn memory channel 8 on or off.
Pressing the key within 10 seconds of pressing the Fkey
will select CARRIER operated scan.
@ 9/TIME key
This key
is used to turn memory channel 9 on or off.
Pressing the key within 10 seconds of pressing the Fkey
will select TIME operated scan.
@ ENT / LOCK key
This key
is used to switch to the direct keyboard
frequency entry mode.
Pressing the key within 10 seconds of pressing the Fkey
will deactivate all functions except the PTT, POWER,
MON!. LAMP, F then ENTER (LOCK) keys.
If you press the F key for longer than 1 second, then
press the ENT key the Tuning control lock
function will
turn on or off.
@SHIFT/REV/" key
Pressing the key will cause the radio to shift from one
offset direction to the other, i.e.+ to - to simplex
where no indicator shows. [- to - - for European
version (TH-47
E) ].
Pressing the key within 10 seconds of pressing the F
key will reverse the transmit/receive frequencise
during repeater operations. If you have selected
simplex this key will not function.
® O/L.OUT key
This key
is used to turn memory channel 0 on or off.
Pressing the key within 10 seconds of pressing the F
key will turn the memory channel lock out function
on
or off.
(/) MHZ/STEP/# key
This key
is used to select the tuning rate of the Tuning
control. When the MHz indicator is lit. the Tuning
control will cause the transceiver to increase or
decrease in 1 MHz steps.
During VFO operation pressing the key within
10
seconds of pressing the F key will select the desired
frequency step.
® SCA N/VM.SCAN key
This key
is used to start or stop scanning.
Pressing the key within 10 seconds of pressing the F
key will start or stop
VFO/Memory scan.
11

• NOT DISPLAYED FUNCTION
• Press the M key then the key below
Key Function Refer
to
M, CALL Displayed
data in call
P.2l
4-4~S
channel.
M, MONI DTMF
memory entry
P. 3l
4~7
mode.
Clear the displayed
M, ENT
memory channel data~
P.2l 4-4-5
• Press the M key for longer than 1 second, then the key
below
Key Function
Referto
Enter the upper limit
M1Sec.4 frequency of
P.24
4-$-4
programmable scan 1
Enter the upper limit
M1Sec,5 frequency of P.24
4-5-4
programmable scan 2
Enter the lower limit
M1Sec.7
frequency of
P.24
4~5~4
programmable scan 1
Enter
the lower limit
M1Sec,8 frequency of
P.24
4-5-4
programmable scan 2
12
• Press the F key for longer than 1 second, then the key
below
Key Function Refer to
flSec,MONI
Recall the DTMF
memory
P.32
4~7
F1Sec.OTSS DTSS Code Selection P.33
4~8~2
f15ec, LOW Battery Saver
function
P.42 4-11
on or off
F1Sec,1
Audio confirmation
BEEP on or off
P.1S
4~2
F1Sec,3 Tone
Alert sound (Pi
PAl
4~1O
Pi Pi or Pul Pul Pull
Displays the upper
F1Sec,4 limit frequency of the P.24
4~S~4
programmable scan 1
Displays
the upper
F1Sec,5
limit frequency of the P24
4-$-4
programmable scan 2
Displays
the lower
F15ec,7 limit frequency of the P 24
4~S~4
programmable scan 1

• Press the F key for longer than 1 second and then the
key
below
Key Function Refer to
Display s the lower
F 1 Sec, B limit frequency of the P.24 4-5-4
programmable scan 2
F 1 Sec, ENT Tuning control lock P.l1 ENT key
FlSec+O
Automatic Power Off
function on or off
PA2 4-12
• Press and hold the key below and turn on the power
switch
Key Function Refer to
OTSS and power
DTSSdeiay time
selection (450!750mS)
P34
4-8 -4
ON
DTMF delay time ( 2
5 and power ON
sec) on or off
P.30 4-6-4
Memory recall mode
6 and power ON selection ( 1
or 2
digits)
P22 4-4-6
• Press and hold the key below and turn on the power
switch.
Key Function Refer
to
Enter the lower limit
8 and power ON
ofthe programmable
P. 17 4-2-4
VFO tuning limit .
Enter
the upper limit
9 and power ON
of the programmable
P.17 4-2-4
VFO tuning limit.
M and power ON MEMORY
RESET
P.19 4-4-2
ENT and power
VFO RESET
ON P.19 4-4-2
SHIFT and power
Switching the Alert
P27. 4-5-10
ON
methods
13

Display panel
<D (2) @ @ @@(!)@ ®
( LO ~K T 1. 5 4;f _~~~- ~ttJJJ Jl
® ® @
<D L OCK
® T X.S
@ -
-
-
•
@ +-
+- El
(European version)
@
@ O
CD DT
@C T
® ~
14
LOCK ON when LOCK function is active.
ON when TX.STOP function is active.
This level meter indicates the relative
receive input strength or battery voltage
level during transmit.
Displays the selected transmitter
offset
direction.
During split channel operation both +
and -indicator light.
ON when Reverse function is active.
ON when Tone function is active.
ON when DTSS function is active.
ON when CTCSS function is active.
On when Tone Alert System is active. The
indicator will flash when a signal is
received.
@ElM
@m'fJ
@8 88 '88 1:
p 8S 88
2] 39
@ AL
®I c:lON
®I I';]
@lAPO
088
•
Displays the selected scan mode.
Flashes when scanning.
Displays the selected scan hold/resume
condition.
Displays the selected
output power .i.e.
Economic·low . Low. Medium. and no
indicator H
i.
On when squelch is open.
Displays the operating frequency
to the
nearest
kHz. the frequency step si ze . or
the tone frequency. Flashes during
VM
SCANNING and MHz scanning.
ON in paging mode.
ON in CLOCK mode.
ON when Priority Alert system is active.
ON when the ON TIMER function is
active.
ON when the OFF TIMER function IS
active.
ON when BATTERY SAVER function is
active.
ON when AUTOMATIC POWER OFF
function is active.
Displays the current
Memory Channel
number.The star indicator is on when the
Memory channel will be skipped during
Memory Channel Scan.
ON whenever the F key is depressed.

4-2. RECEIVER OPERATION
Audio confirmation is provided whenever a front panel
key is depressed. You can disable this function by
pressing the Fkey for longer than 1 second. then pressing
the 1 key.
4-2-1. Receiver Operation
Connect the battery pack and the supplied antenna.
Set the controls as follows:
1. Press the power switch for longer than 0.3 second.
r
TH -27
series
L
, ,_,,_, rIrI
, 1 I.!.t!.t
Iillm I!l APO
TH-47 ,.--
series
.,lIri rIri
." -, l!.t.!.t!.t
Iillm I!l APO
'-- ~
The frequencies shown above are the default frequencies after a
microprocessor reset.
If the display shows incomplete data or you
think the displayed frequency
is in error, reset the microprocessor
Memory Initialization on page
19 .
2. Rotate the VOL control clockwise until a signal or
noise
is heard coming from the speaker.
3. Rotate the tuning control
to selected an open channel.
4. Rotate the SOL control clockwise until the noise just
disappears and the BUSY indicator turns off. This
point is known as the Squelch Threshold point.
5. Select the desired operating frequency using the
tuning control. When a signal
is received the S-meter
will
deflect and the BUSY indicator will turn On.
4-2-2. Frequency Selection
• Dire ct Ke yboard Frequency Entry
1. Press the ENT key to select the ENTER mode.
,----- I
( ENT )
,1..
,
'_ --
, . I
L I!l
APO
2. Within
10 seconds of pressing the ENT key enter the
frequency from most significant
digit to the least
significant digit.
( 4 )
~
------
I
( 5 )
,lIli CC J
."
, 1 1 .• I!.t
( 6 ) L I!l
APO
( 5 ) Before entering 1 kHz digit this
indicator may flash.
The transceiver change frequency after 1 kHz digits have
been entered
(1 kHz digit is not displayed).
If 1 kHz digit indicator flashes. enter the 1 kHz digit
frequency.
If you should make an error before entering all digits.
press the ENT key
twice. and reenter all digits.
15

In 12.5 kHz .or 25kHz step size. direct frequency
selection will be completed in the 10kHz digit. When
you enter the
fo llowing keys for the 1 0k Hz digit. 1 kHz
and 100
Hz digit frequencies are automatically selected
the list below.
(10 kHz dIgit)
Frequency (10 kHz
d,git)
Frequency
key. (kHz I key. 1kHz)
0 00 5 50
1 12.5 6 62.5
2 25 7 75
3 37.5 8 87.5
4 37.5 9 87.5
4-2-3. Step Size Selection
To select the desired tuning or scan step size use the
following procedure:
1. Press the F key momentarily. then press the
MHz/STEP key. The current frequency step size wi ll
be displayed.
( F )
STEP
(MHZ)
I!IAPO
2. Rotate the Tuning control until the desired tuning step
size appears in the display.The frequency step
is
indicated in the chart below.
16
S ±> 10 ±> 1S ±> 20 ±> 1 2. S ±> 2S ±> S
3. To complete the programming of the step size you can
press the MHz/STEP key.
The chart below illustrates the way the displayed frequency will change
when you change from one step size to another.
51015201012525 12525t05101520 , , ,
0,5,10,15 0 0 0
20,25.30,35 25 12.5 10
40,45,50,55 50 25 20
60,65,70,75
75
80,85,90,95 37.5 30
50 50
62.5
60
75
70
87.5
80
For example:
Assume you are presently displaying a frequency of 439.920 MHz and
had previously selected a 20 kHz step size. If you were to change the
step
size to 12.5 kHz the display would then read 439 . 925 MHz.
4-2-4. Pr ogrammable VFO Tuning Limi ts
The radio provide the capability of programming the VFO
tuning range. in 1 MHz band segments. as well a
providing a separate programmable band scan function.
(See section 4-5.) For example you could tell the trans-
ceiver that you only wish
to tune the 144.000 MHz and

145.000 MHz band segment by specifying any fre-
quency
with these two segments. The Tuning controls
would then only tune within these specific bands. The
procedure for specifying the bands
is described below.
1. Rotate the Tuning control until the desired lower
tuning range appears on the frequency display.For
example you might
want to select the 144 MHz band
and dial up
144.100 MHz.
2. Turn
off the transceiver POWER switch. Now press
and hold the
8/CAR key while you turn on the POWER
switch.
3. Rotate the Tuning control until the desired upper
tuning range appears in the frequency display.
4. Turn
off the transceiver POWER switch. Now press
and hold the
9/TIME key while you turn on the
POWER switch.
5. To
confirm that the programming was properly per-
formed rotate the Tuning control. The transceiver
should
not go above or below the programmed band
limits.
6. To clear both programmed limits simultaneously ini-
tialize the VFO
memory reset using the procedures
discussed on page
19.
You can reprogram either limit independently by follow-
ing the appropriate instructions above.
17

4-3_ TRANSMITTER OPERATION
NOTE
1. Ensure that an antenna with a low standing wave
ratio (less than 1.5 SWR) is attached to the
antenna connector before attempting to transmit.
Failure to provide proper termination may result
in damage
to the final amplifier section.
2. Always check that the frequency is clear before
transmitting.
1. Select the desired operating frequency using any of
the methods previously discussed.
2. Check the frequency to see if it is occupied before you
transmit.
3. Press the PTT switch. The ON AIR indicator will light.
and the battery level meter will light.
4. Speak into the microphone. The recommended dis-
tance to the microphone is 5 cm (2 inches).
NOTE
Talking closer may result in overdeviation of your
transmit signal, which might be reported as a loss
of clarity or an excessively wide transmit signal.
Talking too far away may result in reports of
weak audio.
5. Release the PTT switch to return to the receive mode.
The ON AIR
indicator should go out. and the battery
level meter will return to zero.
18
• Time Out Timer
The transceiver has a time-out timer function to prevent
possible problems caused by continuous transmission.
This
function forcibly stops continuous transmission
after
10 minutes. When the timer times out. the trans-
ceiver beeps and automatically returns
to the RX mode.
Press the PTT
switch to transmit again.
• TX. STOP
Pressing the MITX.S key within 10 seconds of pressing
the F key
will set the TX. STOP function on or off.
• Changing Transmitter Output Power
Pressing the LOW key will allows you to select 4 different
transmitter output power levels. The actual transmitter
output power for this unit depends on the power supply
being used.
• H (High power): For maximum output power.
• M (Medium power)
• L (Low power): For short-distance communication.
• EL (Economic Low power): For line-of-sight short-
distance communication.
Output Power
TH-27A127E TH·47A147E
H M H L
EL
M
PS-13
25 2 2 1.5 0.5 20
Manganese Battery 5 2 5 5 2.5
05 20
Alkaline Battery 2.5 2 2 1.5
05 20

4-4_ MEMORY
4-4-1 . Microprocessor Memory Back-up
CAUTION
THE MEMORY IS MAINTAINED BY A RECHARGE-
ABLE SECONDARY LITHIUM BATTERY. WITH THE
BATTERY CASE REMOVED, THE MEMORY
IS RE-
SET TO ITS INITIAL STATE AFTER ABOUT 20
DAYS. A FULLY DISCHARGED BATTERY WILL
RE -
QUIRE APPROX. 10 HOURS TO REACH FULL
CHARGE AFTER INSTALLING A NiCd BATTERY
PACK OR AN EXTERNAL POWER SUPPLY.
4-4 -2. Microprocessor Initialization
The initial state of the microprocessor. as delivered from
the factory
is shown in the chart below.
TH-27A TH-27E TH-47A TH-47E
VFOf . 144
MHz 144 MHz 440MHz 430 MHz
Call CH
f. step 5 kHz 12.5 kHz 25 kH z 25 kHz
Tone 88.5
Hz (,; ') 1750
Hz 88.5 Hz(·:- ) 1750 Hz
frequency
(*l Only when the CTCSS un it TSU-7 IS insta ll ed .
• Memory Reset
IMEMORY RE SET I
Press and hold the M key and turn on the POWER switch.
All the LCD indicator may light. Release the M key. All
user programmed data will be initialized.
IVFO RESETI
Press and hold the ENTER key and turn on the POWER
switch to reset the microprocessors VFO memory.
without destroying the memory channel. automatic di-
aler
DTMF memory channel. Programmable VFO tuning
range.
or call channel data.
4-4-3. Memory Channel
This transceiver provides 40 memory channels .
In addition to serving as a normal memory channel
Memory Channel l is used to store the frequency for the
Priority
Alert function.
4-4-4 . Memory Contents
Each memory channel is capable of storing the following
information;
19

Channel Normal Split
channel channel
RX frequency
0 0
TX frequency NA 0
lone(CTCSS) frequency
0 0
Tone «(TCSS) status
Frequency step 0 0
Shih status, REV onloff
0 NA
DTSS code, DTSS status 0 0
4-4-5, Memory Entry
• Normal channel entry or Odd split channel RX fre-
quency entry
1. Select the desired receiver frequency, tone informa-
tion etc.
2. Press the M key momentarily. The - - indicator will
light in the memory channel display.
( M )
'\
( 0 ) ,flC C
if
, 1_f.l..'!.1 ~
( 5 )
IHPO
3. Select any memory channel (00 - 39) using the
numeric keys.
To enter data in memory, a 2-digit number
is used.
20
Memory channel number will turn off. This indicates that
the receiver data
has been properly stored in memory.
• TX frequency entry (Split memory channel only)
1. Press the ENT key and numeric keys
to select the
desired transmitter
frequency .
2. Press the M key momentarily. The - - indicator will
light on the memory channel display.
3. Press and hold the PTT switch and select the
memory
channel ( 00 - 39) using the numeric keys.
(M) ~ U
~8 Tr
,lIC -,i,
Il@ , ,_" 11.1 --
IHPO
( 0 )
( 5 )
NOTE
,-- --------~
When recall the nothing is stored memory a error
so und w ill be heard
4. The radio return
to the previous mode.