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_smgalaxy_noise_filter_sm2547_mic_schematic2547_mic_schematic

Figure 2-3 Your Transceiver Microphone Schematic.

2547_mic_connector2547_mic_connector

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.

transmitter_test_setuptransmitter_test_setup

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 ADJUSTPOINT MEASUREMENT
RegulatorVoltage 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 OffsetFrequency 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 TP9Connect current meter to TP7 (+) and TP8 VR12VR10 50 mA100 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 andConnect 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 > 12WSpurious EmissionMinimum.Balance PowerBetween CH1 andCH4O.
SSB ALC Set radio to CH 19 USB TX mode.AF signal 3OmV, I KHz to microphone VRI3 11.5 W
SSB CarrierBalance Set radio to CH 19 USB TX mode.Set MIC GAIN Fully Counter Clockwise.Connect Oscilloscope to antenna connector. VR6 Spurious Emission toMinimum.
AM TXHigh Power Set radio to CH 19 AM TX mode.Modulation Off. VR14 3.8 W
AM TXLow Power Set RF POWER fully counterclockwise. VR18 0.5w
RF PowerMeter 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 readingof “4” on TX PWR scale.
AM ModulationMeter 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 readingof 95% on theModulation scale.
FrequencyCounter Adjust  Set radio to CH 19 AM RX mode Set CLARIFIER Control to 12 o’clock.  VC1 onfrequencycounterPCB. Display should be27.1850

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 > 2VS/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 BetweenCH 1 and CH 40
USB Sensitivity Set radio to CH19 USB RX modeSet VOL Control Fully Clockwise.RF SG setting 27.186 MHz, 0.5uV. Mod off. L11,L12 Audio Output > 2VS/N > lOdB
LSB Sensitivity Set radio to CH19 LSB RX modeSet VOL Control Fully Clockwise.RF SG setting 27.184 MHz, 0.5uV. Mod off. L11,L12 Audio Output > 2VS/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 slowlyuntil 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 slowlyuntil squelch justcloses.
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

2547_adjustments2547_adjustments

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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