Vertex Standard VX-600 User manual

1
Contents
Operating Manual Reprint ................................................................................................................................................ 2
Cloning ................................................................................................................................................................................ 10
Specifications ..................................................................................................................................................................... 11
Exploded View & Miscellaneous Parts ......................................................................................................................... 12
Block Diagram .................................................................................................................................................................... 13
Circuit Description ............................................................................................................................................................ 14
Alignment ........................................................................................................................................................................... 17
Test Adapter Schematic .................................................................................................................................................... 22
Board Units (Schematics, Layouts & Parts)
MAIN Unit ...................................................................................................................................................................... 23
VR Unit ............................................................................................................................................................................ 43
SW Unit ............................................................................................................................................................................ 44
Dummy Unit ................................................................................................................................................................... 45
Optional Board Units (Schematics, Layouts & Parts)
F2D-8 2-Tone Decode Unit............................................................................................................................................ 46
VTP-50 VX-Trunk Unit .................................................................................................................................................. 48
FVP-25 Encryption / DTMF Pager Unit ...................................................................................................................... 50
F5D-14 5-Tone Unit ........................................................................................................................................................ 52
©2001 VERTEX STANDARD CO., LTD. Printed in Japan.
VHF Band
Service Manual
VX-600
Introduction
This manual describes the circuit theory, program-
ming procedures, and alignment procedures for the
VHF Portable Transceiver.
Much of the operating flexibility of the is
derived from its versatile "Soft Key" front panel keys.
These keys may be configured for a number of op-
erating functions, as described in this manual.
Following the discussion of transceiver operation,
details regarding programming software, align-
ment, and maintenance will follow.
VERTEX STANDARD CO., LTD.
4-8-8 Nakameguro, Meguro-Ku, Tokyo 153-8644, Japan
VERTEX STANDARD
US Headquarters
17210 Edwards Rd., Cerritos, CA 90703, U.S.A.
International Division
8350 N.W. 52nd Terrace, Suite 201, Miami, FL 33166, U.S.A.
YAESU EUROPE B.V.
P.O. Box 75525, 1118 ZN Schiphol, The Netherlands
YAESU UK LTD.
Unit 12, Sun Valley Business Park, Winnall Close
Winchester, Hampshire, SO23 0LB, U.K.
YAESU GERMANY GmbH
Am Kronberger Hang 2, D-65824 Schwalbach, Germany
VERTEX STANDARD HK LTD.
Unit 5, 20/F., Seaview Centre, 139-141 Hoi Bun Road,
Kwun Tong, Kowloon, Hong Kong

2
Operating Manual Reprint
CONTROLS & CONNECTORS
VOL/PWR (Volume/Power) Knob
TOGGLE Switch
LED Indicator
Steady Green: Signaling off (or Scan active)
Blinking Green: Busy Channel (or Squelch off)
Steady Red: Transmission in Progress
Blinking Red: Battery voltage is low
Blinking Yellow: Receiving a Selective Call
Antenna Jack
TOP SEL (Selector) Key
CH (Channel)Selector
SIDE SEL
(Selector) Key
PTT ( Push To Talk )
Switch
MONITOR Button
LAMP Button
MIC/SP Jack
(External Microphone/
Speaker)
Battery Pack Latch
Sub Microphone
(Noise Canceling Microphone)
Main Microphone
Speaker
16-Button DTMF Keypad
(16-key version only)

3
Operating Manual Reprint
BEFORE YOU BEGIN
Battery Pack Installation and Removal
To install the battery, hold the transceiver with
your left hand, so your palm is over the speaker
and your thumb is on the top of the belt clip. Care-
fully mate the battery four insertion slots with
their corresponding alignment tabs on the trans-
ceiver case, while tilting the Belt Clip outward.
Proper alignment occurs with the battery pack
offset about 1/2 inch from the top edge of the bat-
tery compartment.
Guide the pack to the tabs with a slight inward
pressure, then slide the battery pack upward, un-
til it locks in place with a “Click.”
To remove the battery, turn the radio off and re-
move any protective cases. Slide the Battery Pack
Latch on the bottom of the radio toward the front
panel while sliding the battery down about 1/2
inch. Then lift the battery out from the radio while
unfolding the Belt Clip.
Do not attempt to open any of the re-
chargeable Lithium-Ion pack, as they
could explode if accidentally short-cir-
cuited.
Low Battery Indication
As the battery discharges during use, the volt-
age gradually becomes lower. When the battery volt-
age reaches 6.0 volts, it is time to substitute a freshly
charged battery and recharge the depleted pack. The
LED indicator on the top of the radio will blink red
when the battery voltage is low (6 Volts or lower).
OPERATION
Preliminary Steps
Install a charged battery
pack onto the transceiver,
as described previously.
Screw the supplied antenna
onto the Antenna jack.
Never attempt to operate
this transceiver without an
antenna connected.
If you have a Speaker/Mi-
crophone, we recommend
that it not be connected until you are familiar with
the basic operation of the VX-600.
Operation Quick Start
Turn the top panel’s VOL/
PWR knob clockwise to
turn on the radio on.
Turn the top panel’s CH
selector knob to choose
the desired operating
channel. If you want to se-
lect the operating channel
from a different Memory
Channel Group, pressing
the Soft key (assigned to the Memory Group Up or
Down function) to select the Memory Channel
Group to be you want before selecting the operat-
ing channel.
Note: Some models are programmed so that the
operating channels are selected by the Soft key
and the memory channel group is selected by the
channe selector knob. For further details, contact
your VERTEX STANDARD dealer.
Rotate the VOL/PWR
knob to set the volume
level. If no signal is
present, press and hold
in the MONITOR button
(under the PTT switch)
more than 2 seconds;
background noise will
now be heard, and you
may use this to set the
VOL/PWR knob for the
desired audio level. Press
and hold the MONITOR
CAUTION
Danger of explosion if battery is incorrectly
replaced.
Replace only with the same or equivalent type.
Tilt the Belt Clip
Insert the Battery Pack

4
Operating Manual Reprint
button more than 2 seconds (or press the MONI-
TOR button twice) to quiet the noise and resume
normal (quiet) monitoring.
To transmit, press and
hold the PTT switch.
Speak into the micro-
phone area of the front
panel grille (above the
[D]key) in a normal voice
level. To return to the Re-
ceive mode, release the PTT switch.
Press the Soft key (if assigned to the Scan func-
tion) or switch the TOGGLE Switch to the as-
signed “Scan” position (when so programmed by
your dealer) to start the scanner. The scanner rap-
idly steps through each of the dealer-pro-
grammed channels, looking for incoming calls.
Press the TOP SEL key
(on the top panel) or
SIDE SEL key (the top
button on the left side) to
activate one of the
preprogrammed func-
tions which may have
been enabled at the time
of programming by the
dealer. Similarly, when
using the 16-key version,
the [A], [B], [C], and [D]
function keys activate
one of these functions, if
programmed by the dealer. See the next section
for details regarding the available features.
Switch the top panel’s
TOGGLE switch to the
[A], [B] or [Center] posi-
tion to activate one of the
pre-programmed func-
tions which may have
been enabled at the time
of programming by the dealer. When this switch
is in the [A(left)], [B(right)] or [Center] position,
the feature programmed (by your dealer) to that
switch position will be activated. See the next sec-
tion for details regarding the available features.
Press the DTMF keys on the telephone keypad
while pressing the PTT switch to send DTMF
tones (16-key version only).
If a Speaker/Microphone is available, remove the
plastic cap and its two mounting screws from the
right side of the transceiver, then align the con-
nector of the Speaker/Microphone on the trans-
ceiver body; secure the connector pin using the
screws supplied with the Speaker/Microphone.
Hold the speaker grille up next to your ear while
receiving. To transmit, press the PTT switch on
the Speaker/Microphone, just as you would on
the main transceiver’s body, and speak into the
microphone on a normal voice level.
Note: Save the original plastic cap and its mount-
ing screws. They should be reinstalled when not
using the Speaker/Microphone.

5
Operating Manual Reprint
ADVANCED OPERATION
Soft key and TOGGLE switch Functions
The VX-600 includes the [TOP SEL], [SIDE SEL],
[MONITOR], and [LAMP]keys, and the TOGGLE
switch, while the 16-key version additionally pro-
vides [A], [B], [C], [D]function keys. The Soft key
and TOGGLE switch functions can be customized,
via programming by your VERTEX STANDARD
dealer, to meet your communications/network re-
quirements. Some features may require the purchase
and installation of optional internal accessories. The
possible Soft key and TOGGLE switch program-
ming features are illustrated at the right, and their
functions are explained on next page. For further
details, contact your VERTEX STANDARD dealer.
For future reference, check the box next to each func-
tion that has been assigned to the Soft key and TOG-
GLE switch on your particular radio, and keep it
handy.
:Requires FVP-25 DTMF/Encryption Unit
:Requires FVP-25 DTMF/Encryption Unit
TOGGLE switch (Position)
AB
None
Channel Scan
Dual Watch
High/Low Power
Talk Around
TX Save Disable
Encryption Disable
Lock
Follow-Me Scan
Group recall Shortcut
Functions
center
Group 1
Group 2
Group 3
Group 1
Group 2
Group 3
Group 1
Group 2
Group 3
None
Channel Scan
Dual Watch
High/Low Power
Talk Around
TX Save Disable
Encryption Disable
Follow-Me DW
Call/Reset
Speed Dial
Emergency
Group Up
Group Down
Channel Up
Channel Down
Monitor
Lamp
Functions
TOP SEL
Soft key
SIDE SEL MONITOR LAMP
[A][
B][ C][ D]

6
Operating Manual Reprint
ADVANCED OPERATION
Description of Operating Functions
Channel Scan
The Scanning feature is used to monitor multiple sig-
nals programmed into the transceiver. While scanning,
the transceiver will check each channel for the pres-
ence of a signal, and will stop on a channel if a signal
is present.
One key or switch may be assigned to the Scan func-
tion, as follows:
One of the Soft keys may be assigned for Scan
operation; or
The TOGGLE switch may have one position as-
signed to the Scan function.
To activate scanning:
Press the assigned Soft key, or set the TOGGLE
switch to the assigned position.
The scanner will search the channels, looking for
active ones; it will pause each time it finds a chan-
nel on which someone is speaking.
To stop scanning:
Press the assigned Soft key, or set the TOGGLE
switch to a different position.
Operation will revert to the channel to which the
CH knob is set.
Note: Your dealer may have programmed your radio
to stay on one of the following channels if you press
the PTT switch during scanning pause:
Current channel (“Talk Back”)
“Last Busy” channel
“Priority” channel
“Home” channel
“Scan Start” channel
Dual Watch
The Dual Watch feature is similar to the Scan feature,
except that only two channels are monitored:
The current operating channel; and
The “Priority” channel.
To activate Dual Watch:
Press the assigned Soft key, or set the TOGGLE
switch to the assigned position.
The scanner will search the two channels; it will
pause each time it finds a channel on which some-
one is speaking.
To stop Dual Watch:
Press the assigned Soft key, or set the TOGGLE
switch to a different position.
Operation will revert to the channel to which the
CH knob is set.
High/Low Power
Press the assigned Soft key or switch the Toggle
switch to the assigned position to set the radio’s trans-
mitter to the “Low Power” mode, thus extending bat-
tery life. Press the assigned Soft key again or switch
the TOGGLE switch to the other Position to return to
“High Power” operation when in difficult terrain.
Talk Around
Press the assigned Soft key or switch the TOGGLE
switch to the assigned position to activate the Talk
Around feature when you are operating on duplex
channel systems (separate receive and transmit fre-
quencies, utilizing a “repeater” station). The Talk
Around feature allows you to bypass the repeater sta-
tion and talk directly to a station that is nearby. This
feature has no effect when you are operating on “sim-
plex” channels, where the receive and transmit frequen-
cies are already the same.
Note that your dealer may have made provision for
“Talk Around” channels by programming “repeater”
and “Talk Around” frequencies on two adjacent chan-
nels. If so, the key may be used for one of the other
Pre-Programmed Functions.
TX Save Disable
Press the assigned Soft key or switch the TOGGLE
Switch to the assigned position to disable the Transmit
Battery Saver, if you are operating in a location where
high power is almost always needed.
The Transmit Battery Saver helps extend battery life
by reducing transmit power when a very strong signal
from an apparently nearby station is being received.
Under some circumstances, though, your hand-held
radio may not be heard well at the other end of the
communication path, and high power may be neces-
sary at all times.
Encryption Disable
Press the assigned Soft key or switch the TOGGLE
switch to the assigned position to turn off the optional
voice encryption unit temporarily, for use when an in-
correct setting of (or failure in) the encryption system
at one end of the communication path has made it im-
possible to talk to the other station.
Remember that disabling the encryption will mean that
your transmissions are no longer secure. Return to the
encrypted mode as soon as possible, and do not discuss
any critical or confidential information while in the non-
encrypted mode of operation.

7
Operating Manual Reprint
ADVANCED OPERATION
Lock
Switch the TOGGLE switch to lock the top-panel keys;
this can be enabled to prevent radio settings from be-
ing disturbed.
Follow-Me Scan
“Follow-Me” Scan feature checks a User-assigned Pri-
ority Channel regularly as you scan the other chan-
nels. Thus, if only Channels 1, 3, and 5 (of the 8 avail-
able channels) are designated for “Scanning,” the user
may nonetheless assign Channel 2 as the “User-as-
signed” Priority Channel via the “Follow-Me” feature.
To activate “Follow-Me” scanning, first select the chan-
nel you want to designate as the “User-Assigned Pri-
ority Channel” and Switch the TOGGLE switch to
the assigned position. Then turn the CH selector knob
to the “Scanning Start” channel which has been pro-
grammed by your dealer to activate the scanner. When
the scanner stops on an “Active” channel, the User-
assigned Priority Channel will automatically be
checked every few seconds; if activity is found on the
User-assigned Priority Channel, the radio will switch
between it and the Dealer-Assigned Priority Channel,
if any.
Follow-Me DW
To set up a “Dual Watch” frequency pair using the “Fol-
low-Me” feature, select a channel using the CH selector
knob. Now press the assigned Soft key; pressing the
assigned Soft key locks the current channel as the User-
assigned Priority Channel. Now rotate the CH selector
knob to another channel (not the “Scanning Start” chan-
nel). Your radio will now switch back-and-forth between
the currently-selected channel (shown on the CH selec-
tor knob) and the User-assigned Priority Channel.
During “Follow-Me” scanning (after you have pressed
the key), you can set up the “Dual Watch” feature by
rotating the CH selector knob to another channel. The
radio will then scan back and forth between the origi-
nal User-assigned Priority Channel and the newly-se-
lected channel.
The Priority Channel you have assigned (before press-
ing the key) will be retained in memory until you
change it.
Channel Group Selection
The VX-600 is capable of separating its 48 memory
channels into any of 3 Groups. There is no limit as to
the number of channels which may be assigned to each
Group. The Dealer will have made the Group assign-
ment at the time of channel programming. At the same
time, one of the Soft Keys will be assigned as the
Channel Group Selection key.
To change Channel Groups, press the assigned
soft key to step through the available Groups. Once
the desired Group is reached, rotate the CH selector
knob to select the desired channel within the selected
Group.
You may wish to have the Scanner (described previ-
ously) pass through more than one Group during the
scanning process (normally, scanning is performed
within the current group only). To include the current
Group in the scanning loop, press and hold in the as-
signed Soft key for one second.
To remove a Group from Group Scan, press and
hold in the assigned Soft key again for one second.
Call/Reset
This feature, if enabled, allows the user to change the
3-digit Page Call code, used to call other similarly-
equipped stations. Press the Dealer-assigned soft key,
followed by the three digits representing the Page Call
code of the station you wish to call. Three tones will
be heard after the last key is pressed (the new code
will now be transmitted).
The receiver squelch of the other station will be opened,
and you can begin communication.
Speed Dial
Your Dealer may have pre-programmed Auto-Dial tele-
phone number memories into your radio.
To dial a number, press the Dealer-assigned key
for Speed Dialing, then press the numbered key corre-
sponding to the Auto-Dial memory number list pro-
vided by your Dealer. The DTMF tones sent during
the dialing sequence will be heard in the speaker.
Emergency
The VX-600 includes an “Emergency” feature which
may be useful if you have someone monitoring on the
same frequency as your transceiver’s channel. For fur-
ther details contact your nearest VERTEX STAN-
DARD dealer.

8
ARTS (Auto Range Transpond System)
This system is designed to inform you when you
and another ARTS-equipped station are within com-
munication range.
During ARTS operation, your radio automatically
transmits for about 1 second every 25 seconds (the
interval is programmed by the Dealer) in an attempt
to shake hands with the other station.
If you move out of range for more than two min-
utes, your radio senses that no signal has been re-
ceived, three beeps from the beeper will sound. If
you subsequently move back into range, a single
beep will be heard whenever your radio shakes
hands with the other station.
Operating Manual Reprint
ADVANCED OPERATION
DTMF Paging System
This system allows paging and selective calling, us-
ing DTMF tone sequences.
When your radio is paged by a station bearing a tone
sequence which matches yours, your radio's squelch
will open and the alert ringer will sound (unless you
have disabled it, as described previously).

9
Operating Manual Reprint
ACCESSORIES & OPTIONS
Availability of accessories may vary; some accessories are supplied standard per local requirements, others may be
unavailable in some regions. Check with your VERTEX STANDARD Dealer for changes to the this list.
FVP-25 Encryption/DTMF Pager Unit
F2D-8 2-Tone Decode Unit
F5D-14 5-Tone ENC/DEC Unit
FNB-V68LI 7.4 V 1800 mAh Lithium-Ion Battery
FNB-V69LI 7.4 V 2400 mAh Lithium-Ion Battery
FBA-27 Alkaline Battery Case (6 x AA)
VAC-900 Rapid Desktop Charger
VAC-6900 6-Unit Multi Charger
VCM-1 Mobile Mounting Bracket
VTP-50 VX-Trunk Unit
MH-50A7A Speaker/Microphone (Noise Canceling)
VH-110 Over the Head, Heavy Duty Headset
VH-120 3-Wire Earpiece, Mic, Palm PTT Switch
VH-130 2-Wire Earpiece, Palm Mic/PTT Combo
VH-140 DSP VOX Earpiece Microphone
VH-150 DSP VOX Bone-vibration Headset
VH-160 Earpiece, Mic, Body PTT System
VH-170 Bone-vibration Headset
CE39 Programing Software
CT-70 Radio Programing Cable (Requires VPL-1)
CT-71 PC Programing Cable
CT-72 Radio to Radio Programming Cable
ATV-6A VHF Antenna, 134 ~ 151 MHz (Stubby)
ATV-6B VHF Antenna, 150 ~ 163 MHz (Stubby)
ATV-6C VHF Antenna, 161 ~ 174 MHz (Stubby)
ATV-6XL VHF Antenna, 134 ~ 174 MHz (Untuned)

10
Cloning
The includes a convenient “Clone” feature,
which allows the programming data from one trans-
ceiver to be transferred to another . Here is
the procedure for Cloning one radio’s data to an-
other.
Note: When a cloning isn't made, you correct the fol-
lowing part using "CE39."
When a "Radio to Radio Clone" which is in the
"Miscellaneous" menu is "Disabled," change this
menu to "Enabled."
1. Turn both transceivers off.
2. Remove the plastic cap and its two mounting
screws from the jack on the right side
of the transceiver. Do this for both transceivers.
3. Connect the optional cloning cable be-
tween the jacks of the two transceivers.
4. Press and hold the and (just be-
low the ) switches while turning the trans-
ceiver on. Do this for both transceivers (the or-
der of the switch-on does not matter).
5. On the Destination transceiver, press the
switch (LED indicator will glow green).
6. Now, on the source transceiver, Press the
switch.Data will now be transferred to the Des-
tination transceiver from the source transceiv-
er (LED indicator will glow red).
7. If there is a problem during the cloning process,
sound an error beep from source the transceiver.
Check your cable connections and battery volt-
age, and try again.
8. If cloning is a successful, LED indicator will be
disappeared, turn the Destination transceiver
off. Now turn the source transceiver off.
9. Disconnect the . Replace the plastic cap
and its two mounting screws.
10. You can then turn the transceivers back on, and
begin normal operation.
Optional Cloning Cable CT-72
ABCD
1
4
7

2
5
8
0
3
6
9
#
ABCD
1
4
7

2
5
8
0
3
6
9
#
DealerProgramming of VTP-50 and F5D-14
These procedures are designed to be used by the installing technician after the and has
been installed in the transceiver. To program a 's and board, you will need the
programming interface cable, the Programming diskette, and an IBM PC/AT or PS/2-
compatible tyoe computer.
To enter the Programming mode, use the following procedure:
1. Turn the transceiver off.
2. Turn on the transceiver while holding in the TOP SEL Key and PTT switch.

11
Specifications
GENERAL
Frequency Range: 134 - 160 MHz (A), 148 - 174 MHz (C)
Number of Channels: 48 channels
Channel Spacing: 12.5 / 25 / 30 kHz
PLL Steps: 1.25 / 2.5 / 5 / 6.25 kHz
Power Supply Voltage: 7.4 VDC ±20%
Battery Life (5-5-90 duty): w/FNB-V68LI (1800 mAh): 13 hrs. (17 hrs. w/saver) @ 5 W
w/FNB-V69LI (2400 mAh): 16 hrs. (21 hrs. w/saver) @ 5 W
Operating Temperature Range: –22°F to +140°F (–30°C to +60°C)
Frequency Stability: better than ±2.5 ppm
Dimensions: 2.3" (w) x 6.1" (H)x 1.3" (D) (59 x 155 x 34 mm)
Weight: 0.93 lb. (420 g) w/Antenna, FNB-V68LI and Belt clip
Battery: Lithium-Ion 7.4 V 1800 mAh or 7.4 V 2400 mAh
RECEIVER (Measurements made per EIA standard TIA/EIA-603)
Sensitivity: EIA12-dB SINAD: 0.25 µV
20 dB Quieting: 0.35 µV
Adjacent Channel Selectivity: 75 dB (25 kHz) / 70 dB (12.5 kHz)
Intermodulation: 75 dB (25 kHz) / 68 dB (12.5 kHz)
Spurious and Image Rejection: 75 dB
Hum & Noise: 45 dB / 40 dB
Audio Output: 700 mW @ 16 Ohms, 5% THD
TRANSMITTER (Measurements made per EIA standard TIA/EIA-603)
Power Output: 5.0 / 2.5 / 1.0 / 0.25 W
Modulation System: Direct FM 16K0F3E, 11K0F3E
Conducted Spurious Emissions: 70 dB Below Carrier
FM Hum & Noise: 45 dB (25 kHz) / 40 dB (12.5 kHz)
Audio Distortion (@ 1 kHz): < 3 %
Measurements per EIA standards unless noted above.
Specifications subject to change without notice or obligation.

12
Exploded View & Miscellaneous Parts
Non-designated parts are available only
as part of a designated assembly.
U07230107 PAN HEAD SCREW M2X3B #1 1
U9900094 TAPTITE SCREW M2X5NI#2 4
U44104002 TAPTITE SCREW M2X4NI 7
U20206002 BINDING HEAD SCREW M2.6X6NI 2
U00119006 PAN HEAD SCREW M2X18AU 1
U9900117 TAPTITE SCREW M2X4NI #2 1
U07240202 PAN HEAD SCREW M2X4NI#2 2
U20305007 BINDING HEAD SCREW M3X5B 2
U02206007 SEMS SCREW SM2.6X6B 2
REF. VXSTD P/N Description Qty.
M4090153
SPEAKER
RA0343700
FRONT CASE ASS'Y (16KEY)
RA0343800
FRONT CASE ASS'Y (KEYLESS)
RA0306900 (x2 pcs)
COIL SPRING
RA0297300
HOOK
RA0297000
LATCH PLATE
RA0343500
RUBBER KNOB
RA030720A
KNOB
RA030770B
KNOB
RA0297700
LIGHT GUIDE
MAIN UNIT
SW UNIT
VR UNIT
CP6974001
REAR CASE ASS'Y
(W/ TERMINAL PLATE(-))
RA029800A
RUBBER PACKING
RA0296800
RUBBER PACKING
RA0295300
RUBBER KNOB
(16KEY ONLY)
RA0297600
EXT CAP
RA0215400
SHEET
RA0298300
INTER CONNECTOR
RA0296500
LIGHT GUIDE
RA0239100
INTER CONNECTOR
R6147510
(x2 pcs)
RING NUT
DUMMY UNIT
RA0299400
(x2 pcs)
WASHER
CAUTION
The mic element must be desol-
dered and removed from the PCB
on order to reinstall its protective
rubber cover.
Therefore, be careful not to re-
move this cover unless mic ele-
ment replacement is necessary.





















RA0318200 (x2 pcs)
WASHER (B)
RA0317000
SHEET (SP)
RA0317300
LIGHT SHEET B
RA0305100
HOLDER (+)
RA0298100
RUBBER HOLDER (+)
RA0120500
SPRING CONNECTOR
CP6975001
BELT CLIP ASS'Y
RA0140200
MIC HOLDER
RA0207800
MIC HOLDER*
*
TERMINAL PLATE(-)
U9900088
NYLON WASHER



13
Block Diagram

14
Circuit Description
Overview
The is a VHF FM hand-held transceiver de-
signed to operate in the frequency range of 134 to
174 MHz.
Circuit Configuration by Frequency
The receiver is a double-conversion superhetero-
dyne with a first intermediate frequency (IF) of 22.05
MHz and a second IF of 450 kHz. Incoming signals
from the antenna are mixed with the local signal
from PLL to produce the first IF of 22.05 MHz.
This is then mixed with the 21.6 MHz second local
oscillator (using the 21.6 MHz reference crystal) out-
put to produce the 450 kHz second IF. This is subse-
quently detected to produce the demodulated signal.
The transmit signal frequency is directly generated
by the PLL VCO, and modulated by the signal from
the microphone. It is then amplified and sent to the
antenna.
Receive Signal Path
Front-end RF Amplifier
Incoming RF from the antenna jack is delivered to
the RF Unit and passes through a low-pass filter and
high-pass filter consisting of coils , ,
, , , , and , capacitors
,,,,,,,
, , , , , and ,
and antenna switching diode ( ).
Signals within the frequency range of the transceiver
are then amplified by ( ) and en-
ter a varactor-tuned band-pass filter consisting of
coils , , and , capacitors ,
,,,,,,
, , , , , and ,
resisters , and , and diodes
,,,,, and
(all ) before delivery of the RF signal to the
first mixer.
First Mixer
Buffered output from the VCO is amplified by
() to provide a pure first local signal be-
tween 112.3 and 152.3 MHz for injection to the first
mixer ( ). The 22.05 MHz first mixer
product then passes through monolithic crystal fil-
ters and ( , ±5.5 kHz BW)
to strip away all undesired mixer products.
IF Amplifier
The first IF signal is amplified by (
).
The amplified first IF signal is applied to FM IF sub-
system IC ( ), which contains the
second mixer, second local oscillator, limiter ampli-
fier, noise amplifier, and S-meter amplifier.
The IF signal is then mixed with the second local/
PLL reference oscillator ( ), de-
rived from 21.6 MHz crystal ,to produce the
450 kHz second IF when mixed with the first IF sig-
nal within .
The second IF then passes through the ceramic fil-
ter ( : wide channels),
( : narrow channels) to strip
away all but the desired signal, and is applied to the
limiter amplifier in , which removes ampli-
tude variations in the 450kHz IF, before detection of
the speech by the ceramic discriminator
().
Audio Amplifier
Detected audio from is applied to
() and the audio low-pass filter, and
then through the volume control ( : )
to the audio amplifier (;external
speaker) or (;internal speaker), pro-
viding up to 0.5 Watt to the optional headphone jack
or 16-ohm loudspeaker.
Attention: Audio output is BTL output. Both sides
of the audio output are above ground, and this line
must not be connected to a speaker line which uses
a grounded shield.
Squelch Control
The squelch circuitry consists of a noise amplifier
and band-pass filter within , and noise detec-
tor /( ).
When no carrier received, noise at the output of the
detector stage in is amplified and band-pass
filtered by the noise amplifier section of and
the network between pins 7 and 8, and then recti-
fied by .

15
Circuit Description
The resulting DC squelch control voltage is passed
to pin 19 of the microprocessor . If no carrier
is received, this signal causes pin 6 of
() to go low and pin 89 of to go
high. Pin 6 of signals ( ),
( ) and ( ) to disable the
supply voltage to audio amplifiers and
, while pin 89 makes ( ) hold
the green (Busy) half of the LED off, when pin 6 of
is low and pin 89 of is high.
Thus, the microprocessor blocks output from the au-
dio amplifier, and silences the receiver while no sig-
nal is being received, and also during transmission.
When a carrier appears at the discriminator, noise
is removed from the output, causing pin 19 of
to go low and the microprocessor to blink the busy
LED via .
The microprocessor then checks the DTMF decoder
chip on the Optional Unit, the CTCSS and the CDCSS
code for DTMF or CTCSS or CDCSS code squelch
information, if enabled, respectively. If not transmit-
ting and CTCSS or CDCSS is not activated, or if the
received tone or code matches that programmed, the
microprocessor stops scanning, if active, and allows
audio to pass through the audio amplifier and
( ) to the loudspeaker by enabling
the supply voltage to it via , and .
Transmit Signal Path
Microphone Amplifier
Speech input from the microphone is amplified in
( ), is filtered, and is sent to
() and sent to the Dummy Unit (or Op-
tional Unit). The audio which returned from the
Dummy Unit passes through ( ) to be
pre-emphasized.
The processed audio is then mixed with a CTCSS tone
generated by microprocessor and delivered to
( ) for frequency modulating the PLL
carrier up to ±5 kHz from the unmodulated carrier at
the transmitting frequency.
If an external microphone is used, PTT switching is
controlled by ( ), which signals the mi-
croprocessor when the impedance at the microphone
jack drops.
If a CDCSS code is enabled for transmission, the code
is generated by and delivered to
() for CDCSS modulation.
If DTMF is enabled for transmission, the tone is gen-
erated by the microprocessor and applied to
the splatter filter ( ) in place of speech audio.
Also, the tone is amplified for monitoring in the
loudspeaker.
Noise Canceling Microphone Circuit
Two signals from separate internal microphones
(main and sub) are fed to the positive input (sub)
and to the negative input (main) and of
(). If the same signal level is present at
both main and sub, the main signal will be canceled
at the output of Pin 1 of . In other words, noise
from nearby sources not directly connected to the
transceiver enters the main and sub input at the same
signal and, in the absence of (stronger) voice input,
is therefore canceled out.
When a signal is only input to the main microphone,
and there is no signal at the sub microphone, the
main signal is passed as-is from .
Drivers and Final Amplifiers
The modulated signal from the VCO,
(), is buffered by (
) and amplified by ( ) . The low-
level transmit signal is then applied to the Power
Module ( ) for final amplification up
to a maximum of 5 Watts of output power.
The transmit signal then passes through the antenna
switch ( ), and is low-pass filtered to
suppress harmonic spurious radiation before deliv-
ery to the antenna.
Automatic Transmit Power Control
RF power output from the final amplifier is sampled
by and , and is rectified by
(). The resulting DC is fed back through
( ) to the Power Module, provid-
ing control of the power output.
The microprocessor selects either "High" or one of
three "Low" power levels.

16
Circuit Description
Transmit Inhibit
When the Transmit PLL is unlocked, pin 18 of PLL
chip goes to logic "low." The resulting DC
"unlock" control voltage is passed to pin 20 of mi-
croprocessor . While the transmit PLL is un-
locked, pin 85 of remains low, which then
turns off the Automatic Power Controller
() and ( ) to disable
the supply voltage to the Power Module , dis-
abling the transmitter.
Spurious Suppression
Generation of spurious products by the transmitter
is minimized by the fundamental carrier frequency
being equal to final transmitting frequency, modu-
lated directly in the transmit VCO. Additional har-
monic suppression is provided by a low-pass filter
consisting of , , and and ,
, , , , and , result-
ing in more than 60 dB of harmonic suppression
prior to delivery of the signal to the antenna.
PLL Frequency Synthesizer
The PLL frequency synthesizer consists of the VCO,
( :RX) or (
:TX); VCO buffers ( ),
() ; PLL subsystem IC
() and 21.6 MHz reference crystal .
The frequency stability is ±2.5 ppm within the tem-
perature range of -30° to +60°C. The output of the
21.6 MHz reference is applied to pin 8 of the PLL IC.
While receiving, VCO oscillates between
111.94 and 151.94 MHz according to the transceiver
version and the programmed receiving frequency.
The VCO generates at 111.94 to 151.94 MHz for pro-
viding to the first local signal. In the transmit mode,
the VCO generates 134 to 174 MHz.
The output of the VCO is amplified by , and
is routed to pin 5 of the PLL IC. Also the output of
the VCO is amplified by the and routed to
the first local and the drive chain according
toinstructions from .
The PLL IC consists of a prescaler, fractional divider,
reference divider, phase comparator, and a charge
pump. This PLL IC is a fractional-N type synthesizer
utilizing a 40 or 50 kHz reference signal which is
eighth multiple of the channel step size (5, 6.25 or
7.5 kHz). The input signal from pins 5 and 8 of the
PLL IC is divided down to 40 or 50 kHz and com-
pared at the phase comparator. The pulsed output
signal of the phase comparator is applied to the
charge pump and transformed into a DC signal in
the loop filter. The DC signal is applied to the pin 1
of the VCO and locks to keep the VCO frequency
constant.
PLL data is delivered from DTA (pin 100), CLK (pin
2) and PSTB (pin 98) of the microprocessor .
The data are applied to the PLL IC when the channel
is changed or when transmission switches is changed
to reception (and vice versa). A PLL lock condition is
always monitored by the pin 20 of . When the
PLL is unlocked, the "UL" line goes low.
Miscellaneous Circuits
Push-To-Talk Transmit Activation
The PTT switch on the microphone is connected to
pin 32 of microprocessor
, so that when the PTT switch is closed, pin
85 of goes high. This signals the micropro-
cessor to activate the TX/RX controller
(), which then disables the receiver by in-
terrupting the 5 V supply bus at () to
the front-end, FM IF subsystem IC , and the
receivers VCO circuitry.
At the same time, ( ) and
() activate the TX 5V supply line to enable
the transmitter.

17
Alignment
Introduction
The is carefully aligned at the factory for
the specified performance across the frequency
range specified for each version. Realignment
should therefore not be necessary except in the event
of a component failure, or when altering the ver-
sion type. All component replacement and service
should be performed only by an authorized
representative, or the warranty
policy may be voided.
The following procedures cover the sometimes criti-
cal and tedious adjustments that are not normally
required once the transceiver has left the factory.
However, if damage occurs and some parts subse-
quently are placed, realignment may be required. If
a sudden problem occurs during normal operation,
it is likely due to component failure; realignment
should not be done until after the faulty component
has been replaced.
We recommend that servicing be performed only
by authorized service tech-
nicians who are experienced with the circuitry and
fully equipped for repair and alignment. Those who
do undertake any of the following alignments are
cautioned to proceed at their own risk. Problems
caused by unauthorized attempts at realignment are
not covered by the warranty policy. Also,
reserves the right to change circuits and
alignment procedures, in the interest of improved
performance, without notifying owners.
Under no circumstances should any alignment be
attempted unless the normal function and opera-
tion of the transceiver are clearly understood, the
cause of the malfunction has been clearly pinpointed
and any faulty components replaced, and realign-
ment determined to be absolutely necessary.
Do not attempt to perform only a single step unless
it is clearly isolated electrically from all other steps.
Have all test equipment ready before beginning, and
follow all of the steps in a section in the order pre-
sented.
The following test equipment (and thorough famil-
iarity with its correct use) is necessary for complete
realignment. Correction of problems caused by mis-
alignment resulting from use of improper test equip-
ment is not covered under the warranty policy. While
most steps do not require all of the equipment listed,
the interactions of some adjustments may require
that more complex adjustments be performed after-
wards.
Required Test Equipment
ÌRF Signal Generator with calibrated output level
at 200 MHz
ÌDeviation Meter (linear detector)
ÌIn-line Wattmeter with 5% accuracy at 200 MHz
Ì50-Ohm RF Dummy Load with power rating 10W
at 200 MHz
Ì16-Ohm AF Dummy Load
(Attention : Audio output is BTL output; do not
short "shield" to ground!)
ÌRegulated DC Power Supply (standard 7.5V DC,
3A)
ÌFrequency Counter with 0.2 ppm accuracy at 200
MHz
ÌAC Voltmeter
ÌDC Voltmeter
ÌUHF Sampling Coupler
ÌIBM PC / compatible Computer with Microsoft
DOS v3.0 or later operating system
ÌVertex Standard Connection Cable and
SVC39 Alignment program
Alignment Preparation and Precautions
A 50-Ohm RF Dummy Load and in-line wattmeter
must be connected to the main antenna jack in all
procedures that call for transmission, except where
specified otherwise. Correct alignment is not pos-
sible with an antenna.
After completing one step, read the following step
to determine whether the same test equipment will
be required. If not, remove the test equipment (ex-
cept dummy load and wattmeter, in connected) be-
fore proceeding.
Correct alignment requires that the ambient tem-
perature be the same as that of the transceiver and
test equipment, and that this temperature be held
constant between 20° and 30° C (68 ° ~ 86 ° F). When
the transceiver is brought into the shop from hot or
cold air, it should be allowed time to come to room
temperature before alignment.

18
Alignment
Whenever possible, alignments should be made with
oscillator shields and circuit boards firmly affixed
in place. Also, the test equipment must be thor-
oughly warmed up before beginning.
Note: Signal levels in dB referred to in the alignment
procedure are based on 0 dBµ EMF = 0.5 µV (closed cir-
cuit).
When connecting the plug into the
jack of the , you must remove the
plastic cap and its mounting screws prior to
programming. Please remember to re-attach
the cap and screws when the programming is
complete.
Set up the test equipment as shown for transceiver
alignment, and apply 7.5V DC power to the trans-
ceiver.
The alignment tool outline
Installation of the Alignment Tool
The "alignment mode" is a software-based protocol,
accessed by an "Alignment Mode" command from
the computer while switching the transceiver on. It
is operated by the alignment tool automatically.
During use of the alignment mode, normal opera-
tion is suspended. The alignment tool program pro-
vides all needed operation capability.
The alignment tool consists of an executable file
“SVC39.exe” and an accompanying configuration
file “SVC39.cfg” which should be loaded per stan-
dard DOS procedures. Create a suitable directory,
then copy these files from the distribution diskette
into the new directory. For example, if copying the
file from Drive A, use the following DOS command
sequence:
c:\ mkdir align900 [enter]
c:\ cd align900 [enter]
c:\align900\ copy a:SVC39.*
No further installation steps are required. If you wish
to utilize a different name for the alignment direc-
tory, it will not matter to the executable file.
Booting the Alignment Tool
Change to the “align900” directory (or the directory
name you utilized in the previous section). Now type
on the command line: SVC39 [ENTER] to boot the
alignment tool.
Entering the Alignment Mode
To enter the alignment mode, turn the transceiver
off, then press [0] on the computer keyboard. Now,
turn the transceiver back On. When the command
has been successful, a message on the computer
screen will confirm that the transceiver is now in
the “Alignment” mode.
Action of the Switches
When the transceiver is in alignment mode, the [PTT],
[MON], and [DIAL] switches, as well as the Dial, are
disabled. In the Alignment mode, all of the
transceiver’s operation is remotely controlled by the
PC.
Alignment Sequence
Although the data displayed on the computer’s
screen during alignment is temporary data, it is im-
Important Note
The transceiver must be programmed for use in the
intended system before alignment is attempted. The
RF parameters are loaded from the file during the
alignment process.
In order to facilitate alignment over the complete
operating range of the equipment, it is recom-
mended that the channel data in the transceiver be
preset as per the chart below.
Inline Wattmeter
Deviation Meter
Frequency
Counter
RF Sampling
Coupler
RF Signal
Generator
Transceiver
Power Supply
7.5V DC
CT-71 connection
Cable
PC
MIC/SP
COM port
Channels Frequency (Simplex)
Type- A
Band-LOW
Band-MID
Band-HIGH
134.000
147.000
160.000
148.000
160.000
174.000
Type- C

19
Alignment
portant that you follow the basic alignment sequence
precisely, so that the displayed data and the data
loaded into the transceiver are identical.
Basic Alignment Sequence
1. Enter the alignment mode
2. Upload data from transceiver
3. Align data
4. Download data to transceiver
Alignment Tool Menu
Common Data
The parameters in this section represent "common"
data for all channels. Once these "Common Data"
parameters are correctly aligned, the "TXPOWER,"
"MAX DEV," and "SUB AUDIO DEV," can be trimmed for
each channel, if needed.
During alignment, each parameter is adjusted for a
higher or lower value via the computer’s [] and
[] keys. When the desired value is reached, type
[ENTER] to lock in the new value.
(0) Common Tx :
The first alignment section adjusts transmit-mode
parameters which are common to all channels.
- [0] FREQUENCY
This parameter is used to adjust the PLL reference
frequency. From the " " section, press
[] to activate this alignment sequence.
• Press the [ ] key on the keyboard to activate
the transmitter.
• Press the [] or [] key, as needed, so the counter
frequency is within 100 Hz of the channel center
frequency for the MID channel.
• When the precise frequency is attained, press [
] to lock in the new data.
• Now verify that the HIGH and LOW channels are
also within tolerance.
- [1] HIGH
This parameter is used to align Tx High power (5W).
From the " " section, press [ ] to ac-
tivate this alignment sequence.
• Use the [] or [] key to select the " " frequen-
cy channel in the alignment range.
• Press the [ ] key on the keyboard to activate
the transmitter.
• Press the [] or [] key, as needed, to set the
power output to 5 Watts, as indicated on the ex-
ternal wattmeter.
• When the 5 Watt level is attained, press [ ]
to lock in the new data.
- [2] L1
This parameter aligns the L1 power (0.25 W) level.
From the " " section, press [ ] to ac-
tivate this alignment sequence.
• Press the [ ] key on the keyboard to activate
the transmitter.
• Press the [] or [] key, as needed, to set the
power output to 0.25 W, as indicated on the exter-
nal wattmeter.
• When the 0.25 W level is attained, press [ ]
to lock in the new data.
- [3] L2
This parameter aligns the L2 power (1 W) level. From
the " " section, press [ ] to activate
this alignment sequence.
• Press the [ ] key on the keyboard to activate
the transmitter.
• Press the [] or [] key, as needed, to set the
power output to 1 Watt, as indicated on the exter-
nal wattmeter.
• When the 1 Watt level is attained, press [ ]
to lock in the new data.
- [4] L3
This parameter aligns the L3 power (2.5 W) level.
From the " " section, press [ ] to ac-
tivate this alignment sequence.
• Press the [ ] key on the keyboard to activate
the transmitter.
• Press the [] or [] key, as needed, to set the
power output to 2.5 W, as indicated on the exter-
nal wattmeter.
• When the 2.5 W level is attained, press [ ]
to lock in the new data.
- [5] MAXIMUM DEVIATION
This section adjusts the transmitter’s voice devi-
ation level. From the “ ” section,
select [ ] to enter this alignment sequence.

20
Alignment
• Use the [] or [] key to select the " " frequen-
cy channel in the alignment range.
• Disable any subaudible tone signaling on this chan-
nel, if present.
• Press the [ ] key on the computer keyboard
to start alignment. This activates the transmitter,
and injects a 1 kHz test tone.
• Press the [] or [] key, as needed, to set the
deviation to the desired value (typically 3.9 ~ 4.2
kHz, or 2.0 ~ 2.3 kHz for “ ” channels).
• When the desired deviation level is attained, press
[] to lock in the new value.
- [6] MIC GAIN
This parameter is used to align MIC Gain level.
From the " " section, press [ ] to
activate this alignment sequence.
• Use the [t] or [u] key to select the channel on which
you wish to adjust the MIC Gain.
• Press the [ ] key on the computer keyboard
to start alignment. This activates the transmitter,
and injects a subaudible test tone.
• Use the [] or [] key to find the desired MIC
Gain level is achieved.
• Press the [ ] key on the computer keyboard
to lock in the new MIC Gain level.
- [7] SUB AUDIO DEVIATION
This section adjusts the transmitter’s subaudible
tone deviation level. From the " "
section, select [ ] to enter this alignment sequence.
• After setting the Maximum Deviation in the pre-
vious section, it is now time to align the subaudi-
ble signaling deviation level.
• Use the [] or [] key to select the channel on
which you wish to adjust the Subaudible Devia-
tion.
• Press the [ ] key on the computer keyboard
to start alignment. This activates the transmitter,
and injects a subaudible test tone.
• Press the [] or [] key, as needed, to set the
deviation to the desired value (typically 0.6±0.1
kHz, or 0.4±0.1 kHz for “ ” channels).
• When the desired deviation level is attained, press
[] to lock in the new value.
(1) Common RX :
- [0] TIGHT NOISE SQUELCH
This parameter is used to align the "
" level. From the " " sec-
tion, select [ ] to enter this alignment sequence.
• Set the signal generator output level to –0dBµ EMF
(0.5 µV).
• Press the [ ] key on your computer key-
board to set the “ ” squelch level.
- [1] THRESHOLD NOISE SQUELCH
This parameter is used to align the squelch thresh-
old level. From the “ ” select [ ]
to enter this alignment sequence.
• Set the signal generator output level to –10 dBµ
EMF (0.16 µV).
• Press the [ ] key on your computer key-
board to set the squelch “ ” level.
- [2] RSSI (RECEIVED SIGNAL STRENGTH INDICATOR)
SQUELCH
This section allows adjustment of the RSSI level.
From the “ ” section, press [ ] to
enter this alignment sequence.
• Set the signal generator output level to +3.0 dBµ
EMF ( 0.7 µV ).
• Press the [ ] key on the computer keyboard
to set the RSSI squelch level.
- [3] TXSAVE
This section allows adjustment of the Tx Save ac-
tivation threshold (reducing the transmitter pow-
er in strong-signal environments). From the “
” section, press [ ] to enter this align-
ment sequence.
• Set the Signal Generator output level to +15 dBµ
EMF ( 2.8 µV).
• Press the [ ] key on the computer keyboard
to lock in the TX Battery Saver threshold level.