Galaxy DX 93T User manual

DX 93T
B
SW R
A
MOD
Twin Turbine CDE
OFF TB OFF
PU SH OFF PU SH NB/ANL PU SH
EC H O TIME
OFF
G
DIM
MIC TB
HILO
VO L SQ
PW R
H
MED LAM P
PAD
40dB
OFF MOD
LSB
FM
PA
FUSB
AM
RX
+10KHz
RX/TX
FINE CO ARSE
OFF
5/6 DIGIT
ANL KHz
HIGH SW R ALERT
NB PAD
+10
3
0
SW R
1
20
PW R
MOD
S
+40
80
+60
50
3
30
40
60
40
2
1.5
1
5
10
20
100%
MAX
+20
7
5
9
dB
DX 93T
10 Meter
Amateur Mobile Transceiver
With Built-in Frequency Counter &
StarLite Face Plate
OWNER’S MANUAL
TABLE OF CONTENTS
- 1 -
PAGE
CHAPTER 1
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
CHAPTER 2
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Installing The Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Ignition Noise Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
External Speaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Public Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
CHAPTER 3
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Procedure to Receive and Transmit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Receiving SSB Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Alternate Microphone and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 12

- 2 -
CHAPTER 1 SPECIFICATIONS
GENERAL
Model DX 93T
Frequency Range 28.315 ~ 28.755 MHz
Emission FM/AM/USB/LSB
Frequency Control Phase-Lock-Loop (PLL) Synthesizer
Frequency Stability 0.001%
Temperature Range -30°C to +50°C
Antenna Impedance 50 Ohms
Antenna Connectors Standard SO-239 type
Input Voltage 13.8V DC
Size 7 7/8" (W) x 2 3/8" (H) x 10 3/4" (D)
Weight 4 lb. 10 oz.
TRANSMITTER
AM/FM: 20W/8W/2W (HI/MED/LO)RF Power Output
USB/LSB: 50W PEP
Spurious Emission -50 dB
Unwanted Sideband -50 dB
Audio Distortion 10%
Frequency Response 300 to 2500Hz
Microphone Dynamic
Clarifier Range Coarse: ±6.0KHz, Fine: ±1.0KHz
RECEIVER
Sensitivity for 10 dB (S+N)/N AM: < 0.5 µV; USB/LSB: < 0.25 µV
Sensitivity for 12 dB (S+N)/N FM: < 0.25 µV
Squelch Sensitivity < 0.5 uV
Selectivity -55 dB
Image Rejection -50 dB
AGC Figure of Merit 100 mV for 10dB Change in Audio Output
Audio Power Output 2.5W @ 10% Distortion
Audio Response 300 to 2500 Hz
(SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE)
- 3 -
CHAPTER 2 INSTALLATION
INSTALLING THE RADIO
Choose a convenient location for operation that does not interfere with driver or
passenger. This radio 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 vehicle.
Proceed as follows to install the radio.
1. Locate a convenient area in your vehicle for the installation of the radio.
Hold the mounting bracket with the radio in the location where the radio is to
be installed. Make sure nothing will interfere with either the radio or the
mounting bolts. Mark and then drill holes for the mounting bracket.
2. Most radio antennas come equipped with a PL-259 plug. Connect this plug to
the ANT. Jack in the rear of the radio.
3. Extending from the rear of the radio is a fused red and black wire for the DC
connections to the vehicle’s electrical system. For best performance, it is
strongly recommended that the red lead be taken directly to the positive
terminal on the vehicle’s battery and the black lead be connected to the
nearest chassis ground. (Note: This radio is designed for vehicles with
negative ground systems.)
Connections should be made using appropriate “crimp on” lugs of a size
large enough to make good contact with the bolt used to fasten to the battery
and the chassis ground. It is a good safety idea to install a second fuse that
would provide protection in case the red wire was to “fray” or get pinched
and short to the body of the vehicle, somewhere between the battery and the
radio.
High power radios such as this one require large DC current flow when in the
TX mode. Poor power connections cause supply voltage drops that can
substantially decrease the performance of your radio. A good DC connection
is probably one of the most important things for getting the best transmitter
performance and in some cases, least receiver noise.
4. Mount the microphone bracket near the radio in an easily accessible spot
using the two screws provided.

- 4 -
IGNITION NOISE INTERFERENCE
With weak signals, you may experience interference of the signal by
background noise. This radio has NB and ANL circuits which will help reduce
background noise from sources such as your ignition system. However,
background electrical noise may come from several sources and all noise may not
be eliminated. With extremely weak signals, you can operate this radio with the
engine turned off, which should improve reception. If the ignition noise level is
too high to allow proper operation under most conditions, you should have your
installation of the radio checked by a qualified technician.
ANTENNA
This radio has a jack in the rear for a standard PL-259 antenna plug. If you are
looking for the most range for your transmission, use a vertically polarized,
quarter-wave length antenna. If antenna height is a problem, you may use a
shorter, loaded-type whip antenna although you can expect some loss of
transmission range.
To improve performance, your antenna should be matched to your radio. Your
antenna can be adjusted so that it matches your radio.
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 Public Address (PA) function, first connect an external speaker to
the PA. SP. Jack on the rear of the radio. See the above specifications for a proper
external speaker. Keep the speaker away from the microphone to avoid acoustic
feedback.
- 5 -
CHAPTER 3 OPERATION
CONTROL FUNCTIONS
FRONT PANEL
1. MOD LAMP: When switched on, this Modulation indicator will illuminate
as you speak into the microphone. When you speak louder, it appears bright
because it is on nearly 100 percent of the time and when you speak softer, it
appears dimmer because it is flickering on and off. It does not glow at all
when there is no modulation. This lamp operates in all modes.
2. SWR/MOD/PWR SWITCH: This switch controls the function of the meter
during the transmit mode. In the “SWR” position, the meter indicates the
Standing Wave Ratio (SWR) of your antenna (accurate only in HI power).
There are no adjustments because the SWR circuit in this radio calibrates
itself automatically. When the switch is in the “MOD” position, the green
scale on the meter indicates your percentage of modulation in the AM mode
only. It is most accurate when testing at maximum power output. When this
switch is in “PWR” position, the meter indicates your power output.
3. MICROPHONE JACK: Used to connect microphone.
4. ON/OFF VOLUME CONTROL: This knob controls the volume and power
to the radio. To turn radio on, rotate the knob clockwise. Turning the knob
further will increase the volume of the receiver.
1 2 3
SW R
DX 93T
Twin Turbine
A
MOD
DE
B
C
14 15 16
134 5 768 1110912
OFF
ECH O TIME
40dB
DIM
PW R
MIC TB
OFF PU SH
TB OFF
VOL SQ
PUSH
OFF
PAD
LSB
H
LO MED HI
FM
PA
G
FAM USB
OFF MOD
LAM P
RX
RX/TX
PUSH
NB/ANL
FINE COARSE
+10KHz OFF
5/6 DIGITHIGH SW R A LER T
NB
ANL PAD
KHz
+10
252117 18 2019 22 2423
3
0
SW R
1
20
PW R
MOD
S
+40
80
+60
50
3
30
40
60
40
2
1.5
1
5
10
20
100%
MAX
+20
7
5
9
dB

- 6 -
5. SQUELCH CONTROL: This knob is used to eliminate background noise
being heard through the receiver, which can be disturbing when no
transmissions are being heard through the receiver. To use this feature, turn
the knob fully counterclockwise and then turn clockwise slowly until the
background noise is just eliminated. Further clockwise rotation will increase
the threshold level which a signal must overcome in order to be heard. Only
strong signals will be heard at a maximum clockwise setting.
6. MIC GAIN CONTROL/PUSH TB OFF SWITCH: Adjusts the
microphone gain in the transmit and PA modes. This controls the gain to the
extent that full talk power is available several inches away from the
microphone. In the Public Address (PA) mode, the control functions as the
volume control. Pushing this knob turns the Talkback circuit on and off.
7. TALKBACK (TB) CONTROL: Adjust this knob for desired volume of
Talkback. This is used to monitor your own voice. For example, you could
use this feature to compare different microphones.
8. ECHO CONTROL/PUSH OFF SWITCH: This control is used to adjust
echo effect. Pushing this knob turns the Echo circuit on and off.
9. TIME CONTROL: This control is used to adjust intervals of echo.
10. COARSE/FINE CONTROL/PUSH NB-ANL OFF SWITCH: Allows
variation of the radio operating frequencies above and below the channel
frequency. Although this control is intended primarily to tune in SSB signals,
it may be used to optimize AM/FM signals. Pushing this knob turns the
Noise Blanker (NB) / Automatic Noise Limiter (ANL) circuit on and off. The
Noise Blanker (NB) is very effective in eliminating repetitive impulse noise
such as ignition interference.
11. RX/TX/OFF/RX SWITCH: When in the RX/TX position, the two clarifiers
(Coarse and Fine) function on both receive and transmit. When the switch is
in the RX position, the Fine clarifier functions on receive only and the Coarse
clarifier still functions on both receive and transmit. When in the OFF
position, both clarifiers have no effect on the frequency.
12. CHANNEL SELECTOR: This control is used to select the desired transmit
and receive channel.
13. +10KHz LED: This LED lights green when the +10KHz function is on.
- 7 -
14. FRONT PANEL METER: The front panel meter allows the user to monitor
incoming signal strength, RF output power, SWR level and AM modulation
level.
15. ILLUMINATED FACE PLATE: All faceplate lettering will fully
illuminate to allow the user easy viewing at night. This unique, solid state,
backlight is designed to maximize night vision while minimizing eye fatigue.
Therefore, it is ideal for switch and control recognition day or night.
16. BAND SELECTOR: This switch is used to select the band.
17. RF POWER SWITCH: This switch allows the user to adjust RF power
output.
18. MODE SWITCH: This control allows you to select one of the following
operating modes: PA/FM/AM/USB/LSB.
19. DIM/OFF/40dB PAD SWITCH: When in the DIM position, it lowers the
level of brightness for the meter lamp, frequency display and channel display.
When the switch is in the 40dB PAD position, the 40dB attenuation circuit is
activated. When the switch is in the OFF position, neither the Dim circuit nor
the Attenuation circuit will be active.
20. MOD LAMP/OFF/+10KHz SWITCH: When in the MOD LAMP position,
the Mod Lamp circuit is activated. When the switch is in the +10KHz
position, the frequency is shifted up 10KHz.
21. FREQUENCY COUNTER: This display indicates the frequency of the
selected channel.
22. 5/6 DIGIT SWITCH: Pushing this switch will change the frequency display
from a six digit readout to a five digit readout. It will turn the hundreds digit
on and off. Then a frequency of 28.3056 MHz would read 28.305 MHz.
23. NB/ANL LED: This LED lights green when the NB/ANL circuit is on.
24. CHANNEL DISPLAY: The channel display indicates the current selected
channel.
25. PAD LED: This LED lights green when the 40dB attenuator circuit is on.
NOTES
HIGH SWR ALERT: All three LEDs (NB/ANL, +10KHz & PAD) light red when
your SWR is higher than about 3:1. This alert is accurate only
in HI power. This is not an exact indicator of 3:1 SWR, but it
is an indication that you should check your SWR reading.

- 8 -
REAR PANEL
1. ANTENNA: This jack accepts a 50 ohm coaxial cable with a PL-259 type
plug.
2. DC POWER: This jack accepts the 13.8V DC power cable with built-in
fuses. The power cord provided with the radio has a black and red wire. The
black goes to negative and red goes to positive.
3. PA SP: This jack is for PA operation. Before operating, you must first
connect a PA speaker (8 ohms, 4W) to this jack.
4. EXT. SP: This jack accepts a 4 to 8 ohm, 5 watt external speaker. When the
external speaker is connected to this jack, the built-in speaker will be
disabled.
- 6 -
MADE IN TAIWAN
ANT.
EXT.SP.
+_
POWER
PA.SP.
1 2
3 4
- 9 -
PROCEDURE TO RECEIVE AND TRANSMIT
A. MICROPHONE
The push-to-talk switch on the microphone controls the receiver and transmitter.
Press the switch and the transmitter is activated, release switch to receive. When
transmitting, hold the microphone two inches from your mouth and speak clearly
in a normal voice. This transceiver comes complete with a low impedance
dynamic microphone.
B. PROCEDURE TO RECEIVE
1. Be sure that power source, microphone and antenna are connected to the
proper connectors before going to the next step.
2. Turn VOL knob clockwise to apply power to the radio.
3. Set the VOL for a comfortable listening level.
4. Set the MODE switch to the desired mode.
5. Listen to the background noise from the speaker. Turn the SQ knob slowly
clockwise until the noise just disappears. The SQ is now properly adjusted.
The receiver will remain quiet until a signal is actually received. Do not
advance the control too far or some of the weaker signals will not be heard.
6. Set the CHANNEL selector switch to the desired channel.
7. Adjust COARSE/FINE control to clarify the SSB signals or to optimize
AM/FM signals.
C. PROCEDURE TO TRANSMIT
1. Select the desired channel of operation.
2. Set the MIC GAIN control fully clockwise.
3. If the channel is clear, depress the push-to-talk switch on the microphone and
speak in a normal voice.

- 10 -
RECEIVING SSB SIGNALS
There are four types of signals presently used for communications: FM, AM,
USB and LSB. When the MODE switch on your unit is placed in the AM
position, only standard double-side band and in FM position, only frequency
deviation, full carrier signals will be detected. An SSB signal may be recognized
while in the AM or FM mode by its characteristic "Donald Duck" sound and the
inability of the detector to produce an intelligible output. The USB and LSB
modes will detect upper sideband and lower sideband respectively, and standard
AM signals.
SSB reception differs from standard AM reception in that an SSB receiver does
not require a carrier or opposite side band to produce an intelligible signal. A
single-side band transmitted signal consists only of the upper or the lower side
band and no carrier is transmitted. The elimination of the carrier from the AM
signal helps to eliminate the biggest cause of whistles and tones heard on
channels that make even moderately strong AM signals unreadable. Also, SSB
takes only half the space of an AM channel, therefore two SSB conversations will
fit into each channel, expanding the 40 AM channels to 80 SSB channels. The
reduction in channel space required also helps in the receiver because only half of
the noise and interference can be received with 100% of the SSB signal.
An SSB signal may be received only when the listening receiver is functioning
in the same mode. In other words, an upper side band signal (USB) may be made
intelligible only if the receiver is functioning in the USB position.
If a lower side band (LSB) signal is heard when the receiver is in the USB
mode, no amount of tuning will make the signal intelligible. The reason for this
may be understood if you consider that when the modulation is applied to the
transmitter's microphone in the USB mode, the transmitter output frequency is
increased whereas in the LSB mode the transmitter's output frequency is
decreased.
The result in listening to the receiver is that when the MODE switch is in the
proper position (either USB or LSB), a true reproduction of a single tone of
modulation will result, and if the tone is increased in frequency (such as a low-
pitched whistle or a high-pitched whistle) you will hear the increase in the output
tone of the receiver. If the incorrect mode is selected, an increase in tone of a
whistle applied to the transmitter will cause a decrease in the resultant tone from
the receiver.
- 11 -
Thus when a voice is used in place of a whistle or tone, in the proper listening
mode the voice will be received correctly whereas in the incorrect mode, the
voice will be translated backwards and cannot be made intelligible by the
COARSE/FINE control. When listening to an AM transmission, a correct side
band is heard in either mode since both upper and lower side bands are received.
Once the desired SSB mode has been selected, frequency adjustment may be
necessary in order to make the incoming signal intelligible. The COARSE/FINE
control allows the operator to vary frequency above or below the exact frequency
of the channel. If the sound of the incoming signal is high or low pitched, adjust
the operation of the COARSE/FINE.
Consider it as performing the same function as a phonograph speed control.
When the speed is set too high, voices will be high-pitched and if set too low,
voice will be low-pitched. Also, there is only one correct speed that will make a
particular record produce the same sound that was recorded. If the record is
played on a turntable that is rotated in the wrong direction (opposite side band) no
amount of speed control (COARSE/FINE) will produce an intelligible sound.
An AM signal received while listening in one of the SSB modes will produce a
steady tone (carrier) in addition to the intelligence, unless the SSB receiver is
tuned to exactly the same frequency by the COARSE/FINE control. For
simplicity, it is recommended that the AM modes be used to listen to AM signals.

- 12 -
ALTERNATE MICROPHONES AND INSTALLATION
For best results, the user should select a low-impedance dynamic type
microphone or a transistorized microphone. Transistorized type microphones
have low output impedance characteristics. The microphones must be provided
with a four-lead cable. The audio conductor and its shielded lead comprise two of
the leads. The third lead is for transmit control and fourth is for receiving control.
The microphone should provide the functions shown in the schematic below.
4 WIRE MIC CABLE
Pin Number Mic Cable Lead
1 Audio Shield
2 Audio Lead
3 Transmit Control
4 Receive Control
Fig. 1 Your transceiver microphone schematic.
If the microphone to be used is provided with pre-cut leads, they must be
revised as follows.
1. Cut leads so that they extend 7/16" beyond the plastic insulating jacket of the
microphone cable.
2. All leads should be cut to the same length. Strip the ends of each wire 1/8"
and tin the exposed wire.
- 13 -
Before beginning the actual wiring, read carefully the circuit and wiring
information provided with the microphone you select. Use the minimum heat
required in soldering the connections. Keep the exposed wire lengths to a
minimum to avoid shorting when the microphone plug is reassembled.
Fig. 2 Microphone plug wiring
To wire the microphone cable to the plug provided, proceed as follows:
1. Remove the retaining screw.
2. Unscrew the housing from the pin receptacle body.
3. Loosen the two cable clamp retainer screws.
4. Feed the microphone cable through the housing, knurled ring and washer as
shown Figure 2.

- 14 -
5. The wires must now be soldered to the pins as indicated in the above wiring
tables. If a vise or clamping tool is available it should be used to hold the pin
receptacle body during the soldering operation, so that both hands are free to
perform the soldering. If a vise or clamping tool is not available, the pin
receptacle body can be held in a stationary position by inserting it into the
microphone jack on the front panel. The numbers of the microphone plug are
shown in Fig. 3, as viewed from the back of the plug. Before soldering the
wire to the pins, pre-tin the wire receptacle of each pin of the plug.
Fig. 3 Microphone plug pin numbers viewed from rear of pin receptacle.
6. Be sure that the housing and the knurled ring of Figure 2 are pushed back
onto the microphone cable before starting to solder. If the washer is not
captive to the pin receptacle body, make sure that it is placed on the threaded
portion of the pin receptacle body before soldering.
7. If the microphone jack is used to hold the pin receptacle during soldering
operation, best results are obtained when the connections to pin 1 and 3 are
made first and then the connections to pins 2 and 4. Use a minimum amount
of soldering and be careful to prevent excessive solder accumulation on pins,
which could cause a short between the pin and the microphone plug housing.
8. When all soldering connections to the pins of the microphone are completed,
push the knurled ring and the housing forward and screw the housing onto
the threaded portion of the pin receptacle body. Note the location of the
screw clearance hole in the plug housing with respect to the threaded hole in
the pin receptacle body. When the housing is completely threaded into the
pin receptacle body, a final fraction of a turn either clockwise or
counterclockwise may be required to align the screw hole with the threaded
hole in the pin receptacle body. When these are aligned, the retaining screw
is then screwed into place to secure the housing to the pin receptacle body.
- 15 -
9. The two cable clamp retainer screws should now be tightened to secure the
housing to the microphone cord. If the cutting directions have been carefully
followed, the cable clamp should secure to the insulation jacket of the
microphone cable.
10. Upon completion of the microphone plug wiring, connect and secure the
microphone plug in the transceiver.

MEMO
WARRANTY
This radio is covered by a two
year Limited parts and labor
warranty.
 “Limited” means that we will repair problems caused by factory defects or
normal use at no charge.
 Before returning a radio to us for warranty service, please call our Service
Department for a Repair Authorization Number (RAN). This RAN must be
written below your return address on the outside of the shipping box. Boxes,
which arrive without an RAN, will be refused, and the shipping company
will return the unopened box to you. Be sure to have a pen and paper ready
along with the serial number of your radio before calling. We will give you
the RAN and our shipping address over the phone. The telephone number of
the Service Department is [phone], and we suggest calling between
10:00 AM and 4:00 PM Pacific Time.
 Please include a note with a detailed description of the symptoms. This is
important because it will help the technician who works on your radio to
locate your problem. Intermittent problems are easily overlooked, so be sure
to give as much detail as possible in your note. Also, please include your
daytime telephone number in case our technicians have any additional
questions.
 Do not send your power cord or microphone unless we ask for these items
during our telephone conversation.
 You are responsible for getting the radio safely to us. (We suggest using
United Parcel Service.) You must pay to ship the radio to us, and we will pay
to ship the radio back to you. Since we use UPS and they do not ship to Post
Offices boxes, please provide us with a street address for the return of your
radio.
 We will repair and return your radio as soon as we can. We appreciate your
choosing a Galaxy radio and we want you to be on the air as much as
possible!
Be sure to visit our web site at
www.GalaxyRadios.com

Printed in Taiwan
AT0949010G