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).

Important Note

When connecting the CT-71plug into the MIC/

SP jack of the VX-900, 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.

50-ohm

Dummy Load

 

 

 

RF Signal

Inline Wattmeter

 

 

Generator

 

 

 

 

RF Sampling

 

 

Deviation Meter

 

Transceiver

Coupler

 

 

 

 

 

 

 

 

 

CT-71 connection

MIC/SP

Frequency

Cable

 

Power Supply

 

 

Counter

PC

 

 

7.5V DC

 

COM port

 

 

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.

Frequency

Channels

(Simplex)

Band-LOW 450.000

Band-MID 470.000

Band-HIGH 485.000

Alignment

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-

21