Vertex Standard VX-450 series, Service Manual

Page: 31 / 71

31 VX-450 Series UHF Band Service Manual
Alignment
Alignment Preparation & 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 possi-
ble with an antenna.
Because of the BTL ( B ridged T rans L ess) Amplifier
circuit used in the
VX-450
series, do not connect earth
side of the speaker leads to chassis “ground”.
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, if connected) be-
fore proceeding.
Correct alignment requires that the ambient temper-
ature be the same as that of the transceiver and test
equipment, and that this temperature be held con-
stant between 68 and 86 °F (20 ~ 30 °C). When the
transceiver is brought into the shop from hot or cold
air, it should be allowed time to come to room tem-
perature before alignment.
Whenever possible, alignments should be made with
oscillator shields and circuit boards firmly affixed in
place. Also, the test equipment must be thoroughly
warmed up before beginning.
Note: Signal levels in dB referred to in the alignment
procedure are based on 0 dB μ EMF = 1 μ V.
Test Setup
Setup the test equipment as shown below for trans-
ceiver alignment, apply 7.5 V DC power to the trans-
ceiver.
The Alignment Tool Outline
Installation of the alignment tool

Install the CE115 (PC Programming Software) to
your PC.

“Alignment“ function in the “Radio“ menu tab of
CE115.
Action of the switches
When the transceiver is in the “Alignment mode,“ the
action of the PTT and all PF KEYS are ignored. All of
the action is controlled by the PC.
Caution!
Please never turn off the power supply during
alignment. If the power supply is turned off
during alignment, the alignment data will be
corrupted.
B
ATTERY
T
ERMINAL
P
OLARITY
Inline
Wattmeter
50-ohm
Dummy Load
RF Signal
Generator
AF Signal
Generator
SINAD Meter
Power Supply
7.5 VDC
Computer
(CE115)
FRB-6
Deviation
Meter
Frequency
Counter
MIC/SP
D-Sub 15-pin
Connector
MIC IN
SP OUT B
CT-160
SP/LOAD Switch: LOAD
LOAD Switch: 16
ٛ
Battery Terminal CLONE Port
CT-104A, CT-106, or CT-171
ANT
Sampling
Coupler
FIF-12