Kenwood TR-851A User manual

GOO/ANADI
430MHz ALL MODE TRANSCEIVER
TR-851A
TR-851E
144MHz ALL MODE TRANSCEIVER
TR-751A
TR-751E
INSTRUCTION MANUAL
KENWOOD CORPORATION
CPRINTEG IN JAPAN 850-8111-00 (K, M, T, WXT)
10987654321 2

Thank you for purchasing our latest transceiver. This
unit has been carefully engineered and manufac-
tured to rigid quality standards, and should give you
satisfactory and dependable operation for many
years.
IMPORTANT: $$
Please read this instruction manual carefully before
placing your transceiver in service.
The following explicit definitions apply in this
manual:
Note: If disregarded, inconvenience only, no risk
of equipment damage or personal injury.
Caution: Equipment damage may occur, but not
personal injury.
This Instruction Manual covers the TR-851A/
851€/751A/751E.
When there are differences in operation
separate instructions will be given for each
model. Illustrations show the TR-751A.
CONTENTS
1. BEFORE OPERATION. ..............::ssseeesseeeeeeeees 4
2. SPECIFICATIONS AND ACCESSORIES ........... 5
2-1, SPECIFICATIONS ......... ce eeeeeeeeeeeeeeeeeeee 5
2-2. ACCESSORIES .............000000 . 6
3. INSTALLATION AND CONNECTION.. - 7
“1. INSTALLATION............ccceeeee .7
3-2. CONNECTION . 8
4. OPERATION ......ccccccecssseesseesseecssesssesess 1.10
4-1. CONTROLS AND THEIR FUNCTIONS ..
4-2. RECEPTION........
4-3. TRANSMISSION . 18
4-4, MEMORY........... +18
4-5. SCAN 0... eeccceeeeeeeceeeseneeeeeeeeeeeseaeeeeeees 21
4-6. REPEATER ............cccceecessecceeeceteeeeeeseees 22
4-7. DCL (Digital Channel Link) SYSTEM.. we 2S
4-8. VOICE SYNTHESIZER.............0004 see
4-9. MICROPHONE UP/DWN SWITCH..
5. MAINTENANCE AND ADJUSTMENT... es
5-1. GENERAL INFORMATION ..............ceeeeeee 33
5-2. SERVICE...........scccssssasvescesseceeneneeessueooren
5-3. CLEANING
5-4. IN CASE OF DIFFICULTY
5-5. MICROPROCESSOR BACK-UP LITHIUM
BATTERY REPLACEMENT. ...........ccceeeeesees 34
5-6. ORDERING SPARE PARTS. a
5-7. ADJUSTMENTS..........ccccccceesseeesseseeeeenees
7-1, TU-7 TONE UNIT
7-3. TU- 7 TONE UNIT AND MU-1 MODEM UNIT... 43
7-4. VS-1 VOICE SYNTHESIZER UNIT.............. 43
7-5. OTHER ACCESSORIES ............ 144
8. REFERENCE..............

1. BEFORE OPERATION
Safety precautions
Never remove the case unless specified in this Instruction
Manual. If the internal parts are touched, accidently, a serious
electric shock might occur.
Never touch internal parts.
If a meta! object, such as a hait pin or a needle, comes into
contact with the power socket on the rear panel, a dangerous
electric shock may result. For families with children, never
permit children to put anything, especially metal, inside this
unit.
Touching the power plug when your hands are wet may result
in a serious electric shock
wal
ly . v
JOD SA Never touch with wet hands.
o6
Never pull, bend or extend the power cord. This could
damage the power cord, resulting in a broken cord or short:
circuit,
SN
™ Always grasp the piug.
In case of abnormal smell
If an abnormal smelt or smoke is detected, immediately turn
the power OFF and pull out the power cord. Contact your
dealer or nearest Service Station.
Notes on installation
Do not place the unit m a place which is exposed to direct
sunlight, neat a heating appliance, etc.
Do not store or use the unitin a dusty location or in a moist at-
mosphere. Select a ocation where a:r is well ventilated
To maintain good ventilation, do not put records or a
tablecloth on the unt. Place the unit at feast 10 cm away
from the walls
The unit may not functon properly if used at extremely low,
or freezing temperatures
Cleaning
Do not use volatde solvents such as atcoho!, paint thinner,
gasoline, benzine, etc. to clean the cabinet. Use a silicone
cloth ar a clean dry cloth
Sibcone cloth Thinner Benzine

2. SPECIFICATIONS AND ACCESSORIES
2-1. SPECIFICATIONS
Specification Cia: cee ele eee ; Teele | TR 731A TRS TE i
“Frequency range 430 to 440 MHz | 14410148 MHz | 144 to 146 MHz
cae eae ~~ USB/LSB (J3E), CW (ATA), FM (F3E, F2D
for the contro! signal of the DCL system) i
Antenna impedance 50 ohms i
Power requirement 13.8 VDC +15% !
_ | Grounding Negative
5 ! | Receive mode with no in- OBA
§ | Current drain put signal '
fee | Transmit mode {Max.) { 7.5A | 6A
Frequency stability (20°C to +60°C) | aleiobal | Better than +15x 10°
| Operating temperature \ —20°C to + 60°C (—4°F to + 140°F)
|_ Dimensions (W x H x D) (Projections included) | 180 x 63 x 233 mm | 180 x 63x 213 mm
Weight : , 2.5 kg (5.5 Ibs) | 2.2 kg {4.8 Ibs)
. [HI | 25 W
Output power gesa eS Fists :
i | LOW | 5 W (Adjustable up to out 25 W)
: | USB/LSB i Balanced modulation
5 | modulation i FM : Reactance modulation
= | Spurious radiation Less than —60 dB
& | Cartier suppression (SSB) ' More than 40 dB
Br idab i
& | Unwanted sideband suppression (SSB) More than 40 dB .
‘ Maximum frequency deviation (FM) +5 kHz
_Audio distortion (FM, at 60% modulation) == Less than 3% (300 to 3000 Hz) 7
_ Microphone impedance 7 500 to 600 ohms _|
: ' USB/LSB/CW polar anlairta' a Single conversion superheterodyne
ircuit I ek Peay Prag Spe
¥ | FM sensed ve. Double conversion superheterodyne
ee. - 41.415 MHz |
Intermediate frequency 10.695 MHz2/ ' 10.695 MHz/455 kHz (FM only)
; 455 kHz (FMonly) ) | a ie
5 | Sensitivity | 110.08 SAIN) Less than 0.11 V i Less than 0.13 pV
2 F : _ | FM (12 dB SINAD) Less than 0.18 «V | Less than 0.2 pV
é LORELEI Ook ce : GLE thee 2 2 aHe
, 60 dB Less than 4.8 kHz
Selectivity Mm dB Me than 12 kHz ;
Dek, | es, Clee -60d8 - Less than 24 kHz
Spurious response — Better than 60 dB | Better than 70 dB (Except fd-IF/2)
RIT variable range More than + 1.2 kHz
. Squelch sensitivity i ___Less than 0.1 pV
| Output | More than 2 W across 8 ohms load (5% distortion)
| External speaker impedance ' 8 ohms
. Code NRZ equal-length code
| Modulation _MSK modulation
§ Frequency deviation : +3.5 kHz (Reference)
; s Mark frequency and deviation | 1200 Hz, +2x 10+
o | Space frequency and deviation ar : 1800 Hz, +2x 10% :
| Code transmission speed and deviation ‘| 1200 bits/second, +2x 10
Notes:
1. Circuit and ratings are subject to change without 2. * Recommended duty cycle
notice due to advancements in technology.
1 minute : Transmission
3 minutes: Reception

2-2. ACCESSORIES
Unpack your transceiver carefully and confirm that it is supplied with the following accessories.
Dynamic microphone (TR-751A U.S.A. version only) .........
Dynamic microphone (Except TR-751A U.S.A. version) ..
Hook (TR-851A U.S.A. version only) ..........ccceceeseeeeeree .
Hook (TR-751A U.S.A, version Only) ...........c.seceecssceenereesenreceeceeneeensteeeeenen
Tapping screw (TR-851A U.S.A. version Only).........:ssseeeeeseeeereeeeeeteseeeeaneres (NO9-0633-05) ....
Tapping screw (TR-751A U.S.A. version OMly)...........:--ssseeeeeeeseeeeeereeeeseeenes (N46-3010-46)
Mobile mounting kit
Bracket.........ccseseeee ste sdehdaecceeuasananeaseee david nes svovesecssteeeewetes {A13-0668-04)
Bracket ass’y (Right) ...........ccccsssceeccereesersreneeseeaeeesssnecerceeseesseensanseesees {A13-0666-12)
Bracket ass’y (Left) .. .. {A13-0667-12)....
Cushion .........cceeeeee ... (G13-0823-04) ....
Allen bolt (Black)... ...(N99-0304-04)
Hex socket screw . ...(NO9-0008-04)
Flange nut........... ...(N14-0510-04) ....
Flat washer (Black)...........ccccsessencerseeeeeeeereeeeesesoes ...(N15-1040-45) ....
Flat WaSHE?, ..0...ccccscvccsssasecevcnrsecesccnscnccsnceresonssess ...(N15-1060-46) ....
Spring washer... (N16-0060-46)
Tapping screw .. .. (NO9-0632-05)....
HO WITCH cs cissivissvadnvinntewessnaadoaee to ¥en ccnnaneadaveydeadnak aUecbines te Rdencenboore ver {(W01-0401-05) ... 6
DC power Cable ...........ccececcsseeceeseeeeeeeeeseeeeeeecerseseeseeeeeenseeeeeeaeeeeeeeenes {E30-2053-05).. lea
A-DIM PIUG.........eeeccsecnseceeeeteeeeee ...(EO9-0471-05).. 1 ea.
Spare fuse (8 A) for TR-851A/851E.. ... (FO5-8021-05).. weed ea.
Spare fuse (7 A) for TR-751A/751E.. we (FO5-7025-05)......ccceeeeeeee 1 ea.
FOOt vcs sisssccevevesseaversbescttectcuscesvecanctsacdobeiscsestadseedecdesssilecasessesecaceseeediues (JO2-0439-05)..........cceeeee 4 ea.
INStrUction
MANUA
...........cccecceeeceeeeeeeessnaeeesneeeeueeseenecennecsserersaeeeseneeneeeees
(B50-8111-O0)
.........:.000
1
copy
After unpacking
Shipping container:
Save
the
boxes
and
packing
in
the
event
your
unit
needs
to
be
transported
for
remote
operation,
maintenance,
or
service.

3. INSTALLATION AND CONNECTION
3-1. INSTALLATION
3-1-1. Precautions
1. Avoid direct sunlight, and select a dry, well ven-
tilated location.
2. Since the heat sink is on the rear panel, avoid
placing the equipment with the bottom and rear
sides close to a wall or desk.
3. When installing the equipment in an automobile,
ensure adequate ventilation. Install the equip-
ment in a location where the rear does not make
direct contact with the seat, and is not directly
exposed to vibration.
4. Avoid installing the equipment in front of the car
heater air outlet.
3-1-2. Power supply
The standard operating voltage of these transceivers
is 13.8 V. The current is 7.5 A with the TR-
851A/851E and 6 A with the TR-751A/751E. Do
not use a power supply (either fixed or mobile) that
provides over 16 V with the POWER switch of the
transceiver turned off.
Operation under such conditions will void the war-
ranty. Also, do not use a power supply that does not
supply at least 12 V in transmit or receive. Use of
such supply may cause the performance of the
transceiver to suffer.
3-1-3. Foot installation
Attach the feet (4 pcs.) using the following pro-
cedures,
1. Place the radio with the bottom up.
2. Place each foot on the bottom cover so that the
hole in the feet line up with the holes in the bot-
tom cover.
3. Insert a rivet with pin into the hole of each foot.
(Make sure the pin is not inserted too far or the
tivet will not go in.)
4. Push the pin down securely to complete the in-
stallation.
fuvet
3-1-4. Mounting bracket
A. Secure the transceiver under the dashboard us-
ing the supplied mounting bracket. Install the
bracket as shown below. Do not install
backwards.
Nut
bal
ot
32
_—~
—_——_
Af.
Mounting
Ga
Prat
washer
aT
tat
washer
bracket
4!
Bolt
Spring
rye
7
washer
;
Tapping
screw
3
:
a
Moun
bracket
B. Installing the transceiver
Note:
Make sure that the transceiver will not slip out of
place while operating the vehicle.
Follow the steps below:
1. Lift the lever.
2. Carefully slide the transceiver into the mounting
bracket.
Step 2
3. The angle of the bracket may be adjusted to any
of 5 possible viewing angles by loosening the 4
allen bolts at the top of the bracket using the hex
wrench provided.
After the desired angle has been selected tighten
the 4 bolts.
Step 6
4. Press the lever down to secure the transceiver.
5. By installing a lock thru the keyhole on the side
of the mounting bracket, the lever can be locked
and the transceiver secured.

3-2. CONNECTION
3-2-1. Precautions
1. Before connecting and disconnecting the power
connector, be sure to turn off the power swit-
ches of the transceiver and the DC power supp-
ly.
3-2-2. Fixed station
AC
3-2-3. Mobile SP-50 of SP-40
Transceiver
> To battery
Accessories OC cate
A. Battery connection
Connect the supplied power cable with fuse directly
to the battery terminals. Connecting to the cigarette
lighter socket can cause a poor connection, and ex-
cessive voltage drop.
Caution:
1. When connecting or disconnecting the power
cable to or from the power connector, be sure
that the power switch is always in the ‘‘OFF’’
position.
2. Disconnect the transceiver before jump-starting
or before charging the battery.
2. Observe polarity of the cable. The transceiver
operates on 13.8 VDC, negative ground. Bat-
tery polarity must be correct. The power cable is
color coded:
Red —
Black ~—
+ (Positive) polarity
— {Negative} polarity
Transceiver
Antenna
—_)
Transceiver
as eee
a :
eO. @,
EL AS
“7
ae
.
Rubber grommet
To battery

i When installing the transceiver in a vehicle, consider ease of operation and safety when selecting the installa-
tion location.
Make sure the positive (+) and negative (—)} !ead polarity are correct when wiring to the battery.
Engine compartment <——— f ——> Passenger companment
Select the location
where the power cable
iS protected from heat.
moisture of abrasion
secure the cable.
Chassis or fire watl
To the transceiver
Make sure the cable
Goes mot duectly con-
tact the edge of the hole
by using 3 grommet
Notes: --
1. Before installing the power cable, be sure to
remove the negative lead from the battery for
safety.
2. After installation and wiring, be sure to double
check for correct installation before reconnec-
ting the negative lead to the battery terminal.
3. If the fuse opens, be sure to check that each con-
ductor has not been damaged by short-
circuiting, etc.
Then replace with a new fuse of the same rating.
4. After completing the wiring, wrap the fuse
holder with tape to protect against moisture.
5. Do not remove the fuse even if the power cable
is too long.
@ If the wiring hole in the fire wall or chassis is too
small, disassemble the fuse holder to thread the
wire through the hole.
From passenger
compartment
Oy
Thread Iske this.
=
B. Ignition noise
This transceiver is designed to suppress ignition
noise; however, if excessive noise is present, it may
be necessary to use suppressor spark plugs (with
resistors), or an external noise filter such as the PG-
3B.
Note: -
20 A fuse is used in negative (ground) line for addi-
tional protection.
3-2-4. Antenna
The antenna impedance is 50 ohms, do not use an
antenna with other impedance ratings. Securely at-
tach the antenna.
3-2-5. Key
As shown below, plug the key or electronic keyer in-
to the KEY jack on the back panel. {f the plug does
Not fit, use a commercially available conversion plug
or wire the supplied 3.5 mm dia. plug as shown
below.
Manual key of electromc heyer
Connect as shown.
Ensure proper electronic keyer polarity.

4. OPERATION
4-1. CONTROLS AND THEIR FUNCTIONS @
4-1-1. Front panel
OD ‘5:
| |
(With the TR-851E/751E)}
A KENWOOD “144MHz ALL M(
Note: E 2
All segments on the Display Panel and Indicators are
shown on for this explanation.
@ @® Up/Down (¥ MHz/M.CH A) keys
Use these keys to step frequencies [in the VFO A or
VFO B mode] and Memory Channels [in the MR
(Memory Recall) mode] UP or DOWN.
Note; - —
When the FUNC (Function) indicator is ON, the Down
(¥ MHz) key functions as the F.LOCK (Frequency
Lock) and the Up (M.CH 4) key as the AL (Alert) key.
F.LOCK (Frequency Lock) key
Disables the TUNING knob, keys, and switches and
locks the selected frequency and other settings.
This function is active when the FUNC is ON and
F.LOCK key is pressed.
AL (Alert) key
This switch is used to check the priority channel
(M.CH1). When this switch is depressed M.CH1 will
be checked at about 6-second intervals. This func-
tion is active, when the FUNC is ON and the AL key
is pressed.
@ VOICE key
Press this key to activate the optional voice syn-
thesizer unit VS-1.
TONE key (TR-851A/751A only)
Activates the optional subaudible tone encoder
(TU-7) when it is installed.
This function is active when the FUNC is ON and
TONE key is pressed.
10
vot —@)—SOL RIT —2)— RE
18 PUSH ON i 0 ~~
“FS
MIN AA. af g
@ FUNC (Function) key
Pressing this key changes the functions of the
Up/Down (WV MHz/M.CH &) keys to the F.LOCK and
AL keys and the VOICE key to the TONE key (TR-
851A/751A only). FUNC indicator is ON when the
FUNC key is in the ON position. Each time this key is
pressed, the FUNC indicator alternates.
©) Display panel
The large LCD displays operational information such
as transmit/receive frequencies and memory channel
informations. (See page 12.)
© S & RF meter
This meter operates as the S meter during reception
to indicate signal strength and operates as the RF
meter during transmission to indicate relative
transmit power output.
This meter is set to point approximately to ‘’8’’ in
the high power mode.
Note: : —
The RF meter is calibrated with a 50-ohm dummy
load; the meter readings will differ when the anten-
na’s SWR is high.
S meter