GALAXY Microsystems DX 959 User Manual

Printed In Malaysia

AT0949011A

MIC980508

SOLID STATE CITIZENS BAND

AM/SSB MOBILE TRANSCEIVER

OWNER’S MANUAL

DX 959

TABLE OF CONTENTS

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Installation

Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Mounting The Radio . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Ignition Noise Interference . . . . . . . . . . . . . . . . . . . . . 4

Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Tuning The Antenna For Optimum SWR . . . . . . . . . . 5

External Speaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Operation

Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Frequency List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Procedure To Receive And Transmit . . . . . . . . . . . . . 12

Receiving SSB Signals . . . . . . . . . . . . . . . . . . . . . . . . 13

Alternate Microphones And Installation . . . . . . . . . . . 15

Maintenance And Adjustment . . . . . . . . . . . . . . . . . . . 18

A Few Rules That Should Be Obeyed . . . . . . . . . . . . 19

How Your CB Can Serve You . . . . . . . . . . . . . . . . . . 19

Use Channel 9 For Emergency Messages Only . . . . . 20

Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

SPECIFICATIONS

GENERAL

Channels 40

Frequency Range 26.965 ~ 27.405 MHz

Emission AM/USB/LSB

Frequency Control Phase-Lock-loop (PLL) Synthesizer

Frequency Stability 0.001%

Temperature Range

Input Voltage 13.8 VDC

Antenna Impedance 50 Ohms

Speaker Impedance 8 Ohms

Size 7 7/8” (W) x 9 1/4” (D) x 2 1/8” (H)

Weight 5.5 lbs.

TRANSMITTER

RF Power Output AM : 4W ; USB/LSB : 12W PEP

Frequency Response 300 to 2500 Hz

Frequency Tolerance 0.005%

Spurious Emission Better Than -55 dB

Unwanted Sideband Better Than -55 dB

RECEIVER

Sensitivity for 10 dB (S+N)/N

Squelch Sensitivity Less Than 0.5 uV

Audio Power Output 2W @ 10% Distortion

Image Rejection Ratio -65 dB

AGC Figure of Merit 100 mV for 10dB Change in Audio Output

Audio Response 300 to 2500 Hz

Clarifier Range

(SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE)

-30°C to +50°C

AM : 0.5 uV ; USB/LSB : 0.25 uV

± 1.0 KHz

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INSTALLATION

LOCATION

Plan the location of the transceiver and microphone bracket before starting
the installation. Select a location that is convenient for operation and does not
interfere with the driver or passengers. In automobiles, the transceiver is
usually mounted the dash panel with the microphone bracket beside it.

MOUNTING THE RADIO

The transceiver is supplied with a universal mounting bracket. When
mounting the bracket and radio to your car, make sure it is mechanically
strong. Also, provide a good electrical grounding connection to the chassis of
the vehicle. Proceed as follows to mount the transceiver:

1. After you have determined the most convenient location in your vehicle,

hold the transceiver with mounting bracket in the exact location desired.
If nothing will interfere with mounting it in the desired position, remove
the mounting bolts. Before drilling the holes, make sure nothing will
interfere with the installation of the mounting bolts.

2. Connect the antenna cable plug to the standard receptacle on the rear

panel. Most transceiver antennas are terminated with a type PL-259 plug
and mate with the ANT receptacle.

3. Connect the red DC power input wire (with the fuse) to +13.8V DC.

This wire extends from the rear panel. In automobile installation, +13.8V
DC is usually obtained from the accessory contact on the ignition switch.
This prevent the set being left on accidentally when the driver leaves the
car and also permits operating the unit without the engine running.
Locate the accessory contact on most ignition switches by tracing the
power wire from the AM broadcast receiver in the car.

4. Connect the black lead to –13.8V DC. This is usually the chassis of the

car. Any convenient location with good electrical contact (remove paint)
may be used.

5. Mount the microphone bracket on the right side of the transceiver or

near the transceiver, using two screws supplied. When mounting in an
automobile, place the bracket under the dash so that microphone is
readily accessible.

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IGNITION NOISE INTERFERENCE

Use of a mobile receiver at low signal levels is normally limited by the
presence of electrical noise. The primary source of noise in automobile
installation is from the generator and ignition system in the vehicle. Under
most operating conditions, when signal level is adequate, the background
noise does not present a serious problem. Also, when extremely low level
signals are being received, the transceiver may be operated with vehicle
engine turned off. The unit requires very little current and therefore will not
significantly discharge the vehicle battery.

Even though the transceiver has ANL and NB controls, in some
installations ignition interference may be high enough to make good
communications impossible. The electrical noise may come from several
sources. Many possibilities exist as variations between vehicles require
different solutions to reduce the noise.

ANTENNA

A vertically polarized, quarter-wavelength whip antenna provides the most
reliable operation and greatest range. Shorter, loaded-type whip antennas are
more attractive, compact and adequate for applications where the maximum
possible distance is not required. Also, loaded whips do not present the
problems of height imposed by a full quarter-wavelength whip.

Mobile whip antennas utilize the metal body of the vehicle as a ground
plane. When mounted at a corner of the vehicle they are slightly directional,
in the direction of the body of the vehicle. For all practical purpose, however,
the radiation pattern is nondirectional. The slight directional characteristic
will be observed only at extreme distances. A standard antenna connector
(type SO-239) is provided on the transceiver for easy connection to a
standard PL-259 cable termination.

If the transceiver is not mounted on a metal surface, it is necessary to run a
separate ground wire from the unit to good metal electrical ground in the
vehicle. When installed in a boat, the transceiver will not operate at
maximum efficiency without a ground plate, unless the vessel has a steel
hull.

Before installing the transceiver in a boat, consult your dealer for
information regarding an adequate grounding system and prevention of
electrolysis between fittings in the hull and water.

TUNING THE ANTENNA FOR OPTIMUM S.W.R

Since there is such a wide variety of base and mobile antennas, this section

will strictly concern itself to the various types of mobile adjustable antennas.

Because the antenna length is directly related to the channel frequency, it
must be tuned to resonate optimally on all channels of the transceiver.
Channel 1 requires a longer antenna than Channel 40 because it is a lower
frequency.

Due to the various methods of adjusting antennas for proper S.W.R., we
have chosen what we think is the optimum method:

A. Antenna with adjustment screws (set screws).

1. Start with the antenna extended and tighten the set screw lightly enough

so that the antenna can be lightly tapped with your finger for easy
adjustment.

2. Set your transceiver to Channel 20. Press the PTT (push-to-talk) switch,

and tap the antenna (making it shorter). The S.W.R meter will show a
lower reading each time the antenna is tapped. By continuing to shorten
the antenna, you will notice the S.W.R reading will reach a low point
and then start rising again. This means that you have passed the
optimum point for Channel 20.

Extend the antenna a short distance and again follow the procedure above.
When the lowest point has been reached, switch to Channel 1 and then to
Channel 40 and compare S.W.R readings. They should be almost equal.

NOTE

The proper setting is achieved when the SWR is 1.5 or
below, and when it has the same reading for channels 1
and 40.

B. Antennas which must be cut to proper length

1. Follow the same procedure as above, but adjust the length by cutting in

1/8” increments until a good match is obtained.

2. Be very careful not to cut too much at one time, as once it is cut, it can

no longer be lengthened.

3. The whip is easily cut by filing a notch all the way around and breaking

the piece off with pliers.

If you’re having difficulties in adjusting your antenna, check the following:

a. All doors must be closed when adjusting the antenna
b. Make sure the antenna base is grounded.
c. Check your coaxial cable routing (it may be pinched when routed into

the car)

d. Try a different location in your car (keeping in mind the radiation pattern

you wish.)
e. Is the antenna perfectly vertical?
f. Try a different location in your neighborhood. Stay away from large

metal objects when adjusting (metal telephone or lamp post, fences, etc.)

NOTE

The transceiver will operate into an SWR of 2 to 1
indefinitely and sustain an SWR of 20 : 1 for a maximum
of 5 minutes at rated operating conditions.

EXTERNAL SPEAKER

The external speaker jack (EXT SP.) on the rear panel is used for remote
receiver monitoring. The external speaker should have 8 ohms impedance
and be able to handle at least 4 watts. When the external speaker is plugged
in, the internal speaker is disconnected.

PUBLIC ADDRESS

To use the transceiver as a public address system, connect an external 8
ohms speaker (4 watts minimum) to the PA. SP. jack located on the rear
panel. Direct speaker away from the microphone to prevent acoustic
feedback. Physical separation or isolation of the microphone and speaker is
important when operating the PA at high output levels.

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