Galaxy DX 2547 Service Manual Excerpts

Support, support, support...The Galaxy support department was gracious enough to send the Galaxy Noise Filter schematic with out a request! This is what is missing in most instances these days with large consumer electronics companies. Their either to big to follow up on details, don't know were to get the information, or plain don't care. Another reason for the lack of support for many radios is that the radios are designed, built and documented off shore and shipped directly to the distributor. The distributor doesn't understand radio technology nor do they understand end user customer support. All they see is the chance to make higher profits by cutting out the important link between the factory over seas and themselves. Most of these radios end up in yard sales or the trash soon after the purchase. Sure you can save a few bucks, but what do you do when the thing quits or there is a technical design flaw. Who's out their to follow up on it. Don't think the distributor or mail order company will. They'll drop it like a hot rock and find a new product to make profit on. Not at Galaxy, they support their product 100% and beyond. To be honest there are a few companies that support their products, but increasingly I see more products that are not supported at all. Have you ever tried to get a service manual for the Uniden Washington base radio? They haven't supplied them for many years! Need more be said?

Click On Picture For Close-up.

Galaxy Noise Filter Schematic

Galaxy Noise Filter Schematic.

 

Galaxy Microphone Wiring Diagram. Galaxy DX 2547 Mic Jack Pin Assignments.
Figure 2-3 Your Transceiver Microphone Schematic. Figure 2-4 Microphone plug and pin numbers viewed from rear of pin receptacle.

The following information is from the Galaxy DX 2547 Service Manual supplied with the radio.

 

Figure 4-1, Transmitter Test Setup
Galaxy Transmitter Test Setup Diagram.
Figure 4-2, Receiver Test Setup
Galaxy Receiver Test Setup Diagram.

 

REQUIRED TEST EQUIPMENT
  1. DC Power Supply (13.8VDC, 10A)
  2. RF Wattmeter (100 MHz, SOW)
  3. Multimeter (Digital)
  4. Automatic Modulation Meter
  5. Audio Signal Generator
  1. Frequency Counter (100 MHz)
  2. RF Signal Generator (100 MHz)
  3. Automatic Distortion Meter
  4. Oscilloscope (50 MHz) 
  5. Sinad Meter 

ALIGNMENT PROCEDURES 

This transceiver has been aligned at the factory and does not require any adjustments at installation. The required test equipment listed is used for the test setup or alignment shown in Figure 4-1 Transmitter Test Setup and Figure 4-2 Receiver Test Setup. This test setup is used in part or total during the following adjustments. Refer to Page 43 for adjustment location. 

PLL ALIGNMENT
ITEM U.U.T. (UNIT UNDER TEST) SETTING ADJUST
POINT
MEASUREMENT
Regulator
Voltage
Connect Voltmeter positive lead to power switch.
Connect Voltmeter negative lead to PCB ground.
VR701 13.8 VDC
VCO Disconnect 'short PCB' from TP7, TP8 and TP9.
Set radio to CH 1 AM RX mode.
Connect Voltmeter to TP2.
L14 2.5 VDC t 0.1
Set CLARIFIER Control to 12 o'clock.
Connect Oscilloscope to TP3.
L15  Adjust for max.
Connect Frequency Counter to IC3 Pin 8 VC1 10.2400MHz t 20Hz
 AM Frequency Set radio to CH 1 AM RX mode.
Connect Frequency Counter to TP3.
L20 16.2700MHz t 20Hz 
USB Frequency Set radio to CH 1 USB RX mode.
Connect Frequency Counter to TP3.
L21 16.2725MHz 20Hz
LSB Frequency Set radio to CH 1 LSB RX mode.
Connect Frequency Counter to TP3.
L22 16.2675MHz 20Hz 
TX Offset
Frequency
Set radio to CH 1 AM TX mode.
Connect Frequency Counter to TP3.
VR7 16.2675MHz t 20Hz
AM OSC Set radio to CH 1 AM TX mode.
Connect Frequency Counter to TP5.
L23 10.695OMHz 10Hz 
USB OSC Set radio to CH 1 USB TX mode.
Connect Frequency Counter to TP6.
L24 10.6925MHz t 10Hz
LSB OSC Set radio to CH 1 LSB TX mode.
Connect Frequency Counter to TP6.
L25 10.6975MHz:t 10Hz
TRANSMITTER ALIGNMENT
BIAS Current Set radio to CH 19 USB TX mode.
Modulation Off.
Connect current meter to TP7(+) and TP9
Connect current meter to TP7 (+) and TP8
VR12
VR10
50 mA
100 mA
SSB APC Set radio to CH 19 USB RX mode.
Connect Multimeter to TP7.
VRI7 12.5 VDC
SSB TX Power Connect "short PCB" to TP7, TP8 and
Connect RF Power Meter to antenna jack.
Set radio to CH 19 USB TX mode.
AF signal 30mV, 1 KHz to microphone.
Set RF PWR Fully Clockwise.
Set MIC GAIN Fully Clockwise.
L40,L42,
L43,L44
MAX > 12W
Spurious Emission
Minimum.
Balance Power
Between CH1 and
CH4O.
SSB ALC Set radio to CH 19 USB TX mode.
AF signal 3OmV, I KHz to microphone
VRI3 11.5 W
SSB Carrier
Balance
Set radio to CH 19 USB TX mode.
Set MIC GAIN Fully Counter Clockwise.
Connect Oscilloscope to antenna connector.
VR6 Spurious Emission to
Minimum.
AM TX
High Power
Set radio to CH 19 AM TX mode.
Modulation Off.
VR14 3.8 W
AM TX
Low Power
Set RF POWER fully counterclockwise. VR18 0.5w
RF Power
Meter
Set radio to CH 19 AM TX mode.
Set RF POWER fully Clockwise.
Set SWR/MOD/PWR Switch to PWR position
VR9 For a needle reading
of "4" on TX PWR 
scale.
AM Modulation
Meter
Set radio to CH 19 AM TX mode.
AF signal 30mV, 1 KHz to microphone.
Set MIC Gain fully Clockwise.
Set SWR/MOD/PWR Switch to MOD position 
VR16 For a needle reading
of 95% on the
Modulation scale.
Frequency
Counter Adjust
 Set radio to CH 19 AM RX mode
 Set CLARIFIER Control to 12 o'clock.
 VC1 on
frequency
counter
PCB.
Display should be
27.1850

RECEIVER ALIGNMENT 

AM Sensitivity Set radio to CH 19 AM RX mode.
Set RF GAIN Fully Clockwise.
Set SQ Fully Counter Clockwise.
Set VOL Control at 2 o'clock.
Set NB/ANL switch to OFF position.
Set TONE Fully Clockwise.
Set CLARIFIER Control to 12 o'clock.
Connect RF SG to antenna jack 
Frequency 27.185 MHz, lmV. Mod 30%. 
L2,L3,L5,L6,
L7,L8,L9,L10
Audio Output > 2V
S/N > 10 dB.
Set radio to CH 40 AM RX mode.
RF SG setting 27.405 MHz.
Set radio to CH 1 AM RX mode.
RF SG setting 26.965 MHz. 
L5,L6 For Balance Between
CH 1 and CH 40
USB Sensitivity Set radio to CH19 USB RX mode
Set VOL Control Fully Clockwise.
RF SG setting 27.186 MHz, 0.5uV. Mod off. 
L11,L12 Audio Output > 2V
S/N > lOdB
LSB Sensitivity Set radio to CH19 LSB RX mode
Set VOL Control Fully Clockwise.
RF SG setting 27.184 MHz, 0.5uV. Mod off. 
L11,L12 Audio Output > 2V
S/N >lOdB.
NB Adjust Set radio to CH 18 AM RX mode.
RF SG setting 27.185 MHz, 1000mV Mod off.
Set NB/OFF switch to ON position.
Connect Multimeter to TP1 (D2 cathode). 
L1  DC Voltage to max.
(> 2.OV)
AM Squelch Set radio to CH 19 AM RX mode.
Set SQ Control Fully Clockwise.
RF SG setting 27.185 MHz, 2OmV. Mod 30%.
VR4 Adjust very slowly
until squelch just 
closes.
SSB Squelch Set radio to CH 19 USB RX mode.
Set SQ Control Fully Clockwise.
RF SG setting 27.186 MHz, 20 mV. Mod off.
VR3 Adjust very slowly
until squelch just
closes.
AM S-Meter Set radio to CH 19 AM RX mode.
RF SG setting 27.185 MHz, 100mV. Mod 30%.
VR1  For a reading of "9"
on the "S" scale.
SSB S-Meter Set radio to CH 19 USB RX mode.
RF SG setting 27.186 MHz, 100mV. Mod off.
VR2 For a reading of "9"
on the "S" scale

 

Main PCB Adjustment Location

The Galaxy service manual has many more diagrams including circuit board layouts, block diagram and schematics. Only a small sample have been included in this issue to give the reader a feel for how good the manual is. The manual is professional in every way and will be an valuable asset to anyone who works on the DX 2547.

I don't know for a fact, but judging by Galaxy's past history, much of the manual will probably be available on their site before you know it. CBWI

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