Galaxy DX 2547: Hands-On Review And Performance Tests

The first thing I noticed after removing the top and bottom covers was the mobile chassis mounted in the base chassis. At first, I was disappointed, thinking this was a cheaply made base radio.

They have used the aluminum chassis of their mobile CB radio and designed a base chassis that accepts this sub-assembly utilizing the mobile chassis for the heat sink.

Most base radios were nothing more than a mobile circuit board in a box with extra features and a built-in power supply. Even the very popular Cobra 2000 was a Cobra 148 in a nice box with a frequency counter of two meters and extra features. So there’s really nothing different here.

Specification Of Galaxy DX 2547

Pros and Cons Of Galaxy DX 2547

Inside The Galaxy DX 2547 AM/SSB CB Base Station Radio

The transformer is a small version of the one used in the 100 watt RCI base radios. It’s a toroid type and I would expect it to power this radio with the dual final modification and still have more in reserve. In addition, the power supply regulator has a large heat sink attached to the rear of the radio.

Speaking about a dual final modification, the circuit board has spaces for another 2SC1969 and other components required to increase the output power to that of a 10-meter dual final 30 Watt radio. To get optimum output and truly clean sideband transmission a matched pair of 2SC1969 should be used.

I mention this because the modification sheet I have seen calls for one 2SC1969 not a matched pair. I will cover this in another article sometime in the future.

The following are some power supply voltage measurements made at no load, receive only, and at different transmitter power levels:

The layout is very clean. There are no components on the back of the circuit board. The main circuit board is through hole technology.

This will make many dealers happy. Most dealers don’t like working on surface mount circuit boards. There are some boards in this radio that are surface mount. It’s the coming technology whether we like it or not. More and more components are are only available for SMT.

Peaking the transmitter was disappointing at first. sideband wouldn’t increase at all. The AM carrier would increase to around 6 Watts and the peak modulation would only swing to 12 Watts. After going over and over the tune-up, I realized the the heatsink by the final was getting very hot.

Finally I was able to get 22 Watts PEP sideband. and 6 Watts with a swing to 18 Watts on AM by spreading L29 out. The heatsink didn’t get as hot after spreading this coil.

The controls for power and modulation are as follows:

Mechanically it is well structured and should last for many years. The components on the main PC board are well marked and easy to locate. The top and bottom covers may be a tad too large. I recommend putting the side screws in first and lining up the covers while tightening them.

Then install the top, bottom, and rear screws. I found installing the top and bottom screws first, the covers overlapped at the side seam and was impossible to line them up without doing damage.

And for the operators that like toys in their radios, There’s room for echo boards, speech processors, sound recorders, noise toys and whatever your heart desires. There isn’t a lot of room on the front panel for switches though.

The front bezel has knockouts for other switches and maybe controls. It seems that there are other plans for this bezel. I hope it’s only for Galaxy. I’ve seen to often what happens when a radio case is used for another product.

The end user thinks they are the same inside, when in fact they can be quite different. The cheaper model gives a bad rape to the better unit, after all it’s the same, it looks the same, it must be the same. Just the company that charges more is screwing the public…right? As wrong as these theories and assumptions are, the public hasn’t learned that a radio can look the same but be totally different inside. One example is the Magnum 257.

Magnum International did many hours of engineering on this unit. Most of this engineering didn’t go into the look alike radios. This radio has been hurt by other look alike radios produced by the same Korean factory. Some were single final radios.

The distributors and dealers didn’t go out of their way to point this out. And we didn’t see Radio Shack advertise their copy was unconvertible.

In fact Radio Shack had it in the contract that the radio must not be convertible and if it could be the factory would pay dearly in damages. It’s psychology, would you pick up a snake that looks like one that bit you before?

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?

REQUIRED TEST EQUIPMENT

1. DC Power Supply (13.8VDC, 10A)
2. RF Watt meter (100 MHz, SOW)
3. Multimeter (Digital)
4. Automatic Modulation Meter
5. Audio Signal Generator
6. Frequency Counter (100 MHz)
7. RF Signal Generator (100 MHz)
8. Automatic Distortion Meter
9. Oscilloscope (50 MHz)
10. Sinad Meter

Galaxy Noise Filter Schematic

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.

Galaxy DX 2547 Clarifier Mod

Most operators that use sideband have unlocked clarifiers. Unlocking the clarifier means that the clarifier will change both the transmitter frequency as well as the receiver frequency. They will track together when this is done properly.

There are many benefits to having this modification done. First, two operators having a conversation on sideband with unlocked clarifiers that are tuned to one another can be heard by others without having to retune on every transmission.

Second, it two operators are unlocked, only one need tune to the other and they are both transmitting on the same frequency. Third, if the clarifier is unlocked and expanded, all the above is true and then the radio can tune between channels or even slide a full channel, depending on the radio’s capabilities.

To unlock and expand the clarifier do the following:

Make sure the radio isn’t connected to a power source.

Remove D68 a 1N4148 diode.

(Fig. 1) Remove R113 a 47 ohm resistor.

(Fig. 1) Remove R153 a 2.7K resistor.

(Fig. 2) Jumper D38 a 1N4148 diode with a jumper wire.

(Fig. 1) Jumper R114 a 2.2K resistor with a jumper wire.

(Fig. 1) Run a wire from 8 volts constant to J9 pin F1.

(Fig. 1) Triple check your work before applying power to the radio. Once you’re certain that everything has been properly changed, plug in the radio and turn it on for 15 to 20 minutes and proceed to the alignment step.

Figure 1

Figure 2

Now the radio needs to be put back to center slot. With the clarifier switch in the OFF position, adjust the following.

Turn the clarifier ON and verify, with the clarifier at the 12 0’clock position, that the radio is on center slot. 26.9650. The clarifier will shift the transmitter and receiver frequency at least + 2.4KHz and – 6.3KHz. 

​This makes it easy to pick up those operators on even frequencies. The clarifier becomes more sensitive once this modification has been made. Much to my surprise, it wasn’t to difficult to tune in 5KHz down.

Also, once you have set the clarifier down 5KHz, to go back up 5Khz, just switch the clarifier off.

Frequency Conversion For Galaxy DX 2547 – Channel Mods

Before you start, make sure the radio isn’t connected to a power source!

This is a 4 position rotary switch conversion Reference Picture Below

1. Remove the radio covers, all knobs, and front bezel.

2. Remove the headphone jack from the front panel and leave wired.

3. Heat shrink headphone jack and secure to inside of chassis with double sided mounting foam. (See Figure 2)

4. Turn the shaft of the rotary switch to position 2.

5. Mount the switch in the hole for the headphone jack and position the flat side of the shaft toward the bottom of the radio.

6. Wire according to the schematic below (See Figure 1) and reassemble the radio.

Figure 1

Figure 2

Galaxy DX 2547 Photo Shoot

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.

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.

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.

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

Galaxy 2527 CB Base Station Performance Review

This is the first base station in the line of Galaxy CB radios. In these days of converted 10-meter radios, companies like Cobra, Midland and Uniden seem to be trimming their CB radio lines. Cobra with the elimination of their base station radios. Midland back in the hay days was one of the first manufacturers with a line of true single sideband radios now with only one mobile in their SSB lineup. Uniden earlier dropped the PC122, a low cost AM/SSB mobile. More recently they have eliminated the rest of the SSB line with the removal of the Grant mobile and the Washington base. The only other SSB brand with an AM/SSB base station CB radio is Texas Ranger. Cherokee has a base radios on their web site, but they aren’t to be found in the real world.

With all the manufacturers moving away from base station and SSB CB radios, it was a surprise to me when I learned of the new Galaxy DX 2547 CB base radio. It sure made me wonder what might be so special about this radio that would make sell in the current marketplace. Will it be the replacement for the Uniden Washington or the Cobra 2000 GTL? Or is it somewhere in between? These are the reasons for picking this radio as cover story of the first web edition of CB World Informer.

The radio is made for Galaxy, to Galaxy specifications by RCI. The photos on the Galaxy site and the photos on the box, although very professionally done, don’t do the radio justice. I wasn’t able to capture the true appearance of the radio face with my camera either. I tried many lighting sources and camera settings.​

The radio just looks so much better in person. A customer came into the store and said “I saw the new Galaxy base on the web, I wasn’t impressed.” I then showed them the radio and they immediately said “I like that, it’s a nice looking radio.” I’ll do my best to describe the face of the radio. 

The face color is a metallic platinum color with charcoal gray accents and knobs. The indicator area is black giving a high contrast for the LED and meter display. The face has black lettering on the platinum background while there is white lettering on the charcoal and black backgrounds. It is much more impressive to view the real radio.

Looks may be very important, but the performance and functionality is paramount. The DX 2547 has all the features of the past top of the line CB base radios of the recent past and then some. Little things like front legs that flip down tilting the radio for better viewing don’t add to the cost of the radio but make a difference in making it user friendly. Sometimes it’s simple well thought out features like this that make a radio stand out from the competition.

Below is a picture of the radio with all the listed control and indicator functions so you can familiarize your self with the radio. Click on picture for close-up view.

Below are a list of controls and indicators with comments about each of them

Now for the performance test of the DX 2547. First, this radio came from a distributor and no one Knew this was going to be tested and reviewed by CB World Informer.

There is no reason to expect any radio to perform differently from this on tested, although this one has a quirk in the ANL function which is covered above. I’ve submitted and E-mail to Galaxy tech support about this and will add their response as soon as it’s received.

UPDATE

Galaxy returned my E-mail and confirmed the problem by checking some older and newer DX 2547 radios.

The problem is that the J6 connector on the main circuit board is reverse on my radio and others at their site. It’s unclear how many radios are involved, but the solution is simple. Unsolder the three pin J6 connector from the main circuit board then rotate it 180 degrees and re-solder it.

Checking the frequency stability from cold to warm, I found it took about 15 minutes for the radio to warm up and it settled down close to center slot after changing about 250Hz . This may vary from radio to radio, but I would expect it to be close.

The frequency from the factory was within 100Hz of center slot and the counter alignment was on the money. As far as transmitter performance, both AM and SSB audio are very high quality.

The stock mic is adequate, but it sounded better with an EC-2018 turbo echo mic from RF Limited with or without echo. It will sound great with an Astatic amplified mic, especially a D104 type base mic. Out of the box the AM modulation peaks around 50% and the power readings are listed below.

Testing the receiver with the signal generator, the radio seemed to meet the specifications. It performed as well as or better than most radios on the market. The sensitivity is very good and adjacent channel rejection is also impressive.

But the true test is on the air with peaked and over modulated radios in close proximity. Being located in the middle of a wholesale produce market, there are hundreds of over the road drivers running power delivering in the area and in the building that my shop is located in. This is one of the best test beds for receiver performance.

With the radio connected to a Solarcon I-Max 2000, I scanned around listening  for familiar voices. After monitoring AM for a couple of hours, I found the receiver to be quite sensitive and exceptionally clear.

With the tone control set at mid-way the audio frequency response was the best I’ve heard from solid state equipment. Transmissions from the regular operators I’m used to hearing sounded fuller with just enough bass response.

The sideband receiver was equally clear. The radio has a natural sound on sideband that’s easy to listen to. Tuning into a station is easy with this clarifier. Turning the clarifier off worked well on most signals and I think this feature may convert some operators to sideband. In time with more frequency stable radios on the market, the need to constantly tune in stations may be a thing of the past eliminating the most common reason people won’t use sideband.

Testing the squelch, I found it very smooth cutting in and out. There was no pop or click as signals came in breaking the squelch. It also worked very well on sideband.

I’m not a squelch user myself because most of them are erratic and at times choppy. I find more often than not, calls get missed or parts of conversations are cut out because the squelch can’t be properly set. This one works pretty well. It’s one worth giving a try.

On air transmission reports were very good. The audio was clear on both modes and at all power settings. The modulation wasn’t super compressed at the lowest power settings as it is on some radios.

The auto calibrating SWR meter is very convenient, no more keying up at either end of the band and calibrating the meter before you get your reading. Just go to the channel, key up and there it is.

During the on air tests I didn’t encounter any interference that impeded communication. There was slight interference from stations within a quarter mile the next channel over, but I would expect this from any other radio and far worse on most.

The Galaxy filter did reduce the noise level at the audio end. You won’t see a reduction in S meter reading but it smoothes the audio out reducing harsh spikes from reaching the audio amplifier.

There is a cost to this. Weak signals become difficult to understand with the high frequency removed from the audio signal.

This filter cuts the high frequency out so well, the tone control has almost no effect on the audio. Many signals seem muffled, but under extreme noise conditions, this may be worth getting use to.

Galaxy DX 2547 Specifications

This radio comes with both a detachable AC and DC power cord. It’s not a bad size for a camping trailer where the DC cord will come in handy.

In addition to a user manual, Galaxy includes a service manual. This manual is complete with schematics (except the Galaxy noise blanker PCB), exploded parts drawing, PCB drawings, mic wiring, parts list, alignment procedures, adjustment location drawing, test equipment setup, and block diagram. This hard copy manual is worth a $20.00 bill, and more when you need it.

Galaxy warranties the radio for 2 years from the date purchased or if you lost your receipt, 26 months from the date of manufacture. A little note from the warranty policy page may be of interest to the readers. Galaxy uses a “R” as the first character of the serial number  to denote a refurbished radio. Always check for this when you make or receive a new purchase.

One thing I would change, a small one but an important one, the knobs should have a light colored pointer. The position of the knobs is difficult to see even in decent lighting. Although priced in the $320.00 to $360.00 retail range, it does have many features for the money. This radio like other Galaxy models seems to be designed by radio operators, not just hatched from an engineer’s desktop. It certainly appears Galaxy did their homework on the user and engineering level.

The features that are desirable are there and work very well. Time will tell if there’s room for a high quality 40-channel AM/SSB base station CB radio in this seemingly 10-meter radio market. A market, ironically that Galaxy was very instrumental in helping to create with their 10–meter line of radios. 

Performance Test Of The DX 2547

This is the first base station in the line of Galaxy CB radios. In these days of converted 10-meter radios, companies like Cobra, Midland and Uniden seem to be trimming their CB radio lines.

Cobra with the elimination of their base station radios. Midland back in the hay days was one of the first manufacturers with a line of true single sideband radios now with only one mobile in their SSB lineup.

Uniden earlier dropped the PC122, a low cost AM/SSB mobile. More recently they have eliminated the rest of the SSB line with the removal of the Grant mobile and the Washington base. The only other SSB brand with an AM/SSB base station CB radio is Texas Ranger. Cherokee has a base radios on their web site, but they aren’t to be found in the real world.

With all the manufacturers moving away from base station and SSB CB radios, it was a surprise to me when I learned of the new Galaxy DX 2547 CB base radio. It sure made me wonder what might be so special about this radio that would make sell in the current marketplace.

Will it be the replacement for the Uniden Washington or the Cobra 2000 GTL? Or is it somewhere in between? These are the reasons for picking this radio as cover story of the first web edition of CB World Informer.

The radio is made for Galaxy, to Galaxy specifications by RCI. The photos on the Galaxy site and the photos on the box, although very professionally done, don’t do the radio justice. I wasn’t able to capture the true appearance of the radio face with my camera either.

I tried many lighting sources and camera settings. The radio just looks so much better in person. A customer came into the store and said “I saw the new Galaxy base on the web, I wasn’t impressed.”

I then showed them the radio and they immediately said “I like that, it’s a nice looking radio.” I’ll do my best to describe the face of the radio. The face color is a metallic platinum color with charcoal gray accents and knobs.

The indicator area is black giving a high contrast for the LED and meter display. The face has black lettering on the platinum background while there is white lettering on the charcoal and black backgrounds. It is much more impressive to view the real radio.

Looks may be very important, but the performance and functionality is paramount. The DX 2547 has all the features of the past top of the line CB base radios of the recent past and then some.

Little things like front legs that flip down tilting the radio for better viewing don’t add to the cost of the radio but make a difference in making it user friendly.

Sometimes it’s simple well thought out features like this that make a radio stand out from the competition.

Below is a picture of the radio with all the listed control and indicator functions so you can familiarize your self with the radio. Click on picture for close-up view.

Now for the performance test of the DX 2547. First, this radio came from a distributor and no one Knew this was going to be tested and reviewed by CB World Informer.

There is no reason to expect any radio to perform differently from this on tested, although this one has a quirk in the ANL function which is covered above. I’ve submitted and E-mail to Galaxy tech support about this and will add their response as soon as it’s received.

UPDATE

Galaxy returned my E-mail and confirmed the problem by checking some older and newer DX 2547 radios.

The problem is that the J6 connector on the main circuit board is reverse on my radio and others at their site. It’s unclear how many radios are involved, but the solution is simple. Unsolder the three pin J6 connector from the main circuit board then rotate it 180 degrees and re-solder it.

Checking the frequency stability from cold to warm, I found it took about 15 minutes for the radio to warm up and it settled down close to center slot after changing about 250Hz .

This may vary from radio to radio, but I would expect it to be close. The frequency from the factory was within 100Hz of center slot and the counter alignment was on the money.

As far as transmitter performance, both AM and SSB audio are very high quality. The stock mic is adequate, but it sounded better with an EC-2018 turbo echo mic from RF Limited with or without echo.

It will sound great with an Astatic amplified mic, especially a D104 type base mic. Out of the box the AM modulation peaks around 50% and the power readings are listed below.

Testing the receiver with the signal generator, the radio seemed to meet the specifications. It performed as well as or better than most radios on the market. The sensitivity is very good and adjacent channel rejection is also impressive. But the true test is on the air with peaked and over modulated radios in close proximity.

Being located in the middle of a wholesale produce market, there are hundreds of over the road drivers running power delivering in the area and in the building that my shop is located in. This is one of the best test beds for receiver performance.

With the radio connected to a Solarcon I-Max 2000, I scanned around listening  for familiar voices. After monitoring AM for a couple of hours, I found the receiver to be quite sensitive and exceptionally clear. With the tone control set at mid-way the audio frequency response was the best I’ve heard from solid state equipment.

Transmissions from the regular operators I’m used to hearing sounded fuller with just enough bass response.

The sideband receiver was equally clear. The radio has a natural sound on sideband that’s easy to listen to. Tuning into a station is easy with this clarifier. Turning the clarifier off worked well on most signals and I think this feature may convert some operators to sideband.

In time with more frequency stable radios on the market, the need to constantly tune in stations may be a thing of the past eliminating the most common reason people won’t use sideband.

Testing the squelch, I found it very smooth cutting in and out. There was no pop or click as signals came in breaking the squelch. It also worked very well on sideband. I’m not a squelch user myself because most of them are erratic and at times choppy.

I find more often than not, calls get missed or parts of conversations are cut out because the squelch can’t be properly set. This one works pretty well. It’s one worth giving a try.

On air transmission reports were very good. The audio was clear on both modes and at all power settings. The modulation wasn’t super compressed at the lowest power settings as it is on some radios.

The auto calibrating SWR meter is very convenient, no more keying up at either end of the band and calibrating the meter before you get your reading. Just go to the channel, key up and there it is.

During the on air tests I didn’t encounter any interference that impeded communication. There was slight interference from stations within a quarter mile the next channel over, but I would expect this from any other radio and far worse on most.

The Galaxy filter did reduce the noise level at the audio end. You won’t see a reduction in S meter reading but it smoothes the audio out reducing harsh spikes from reaching the audio amplifier.

There is a cost to this. Weak signals become difficult to understand with the high frequency removed from the audio signal.

This filter cuts the high frequency out so well, the tone control has almost no effect on the audio. Many signals seem muffled, but under extreme noise conditions, this may be worth getting use to.

Galaxy DX 2547 Specifications

This radio comes with both a detachable AC and DC power cord. It’s not a bad size for a camping trailer where the DC cord will come in handy. In addition to a user manual, Galaxy includes a service manual.

This manual is complete with schematics (except the Galaxy noise blanker PCB), exploded parts drawing, PCB drawings, mic wiring, parts list, alignment procedures, adjustment location drawing, test equipment setup, and block diagram. This hard copy manual is worth a $20.00 bill, and more when you need it.

Galaxy warranties the radio for 2 years from the date purchased or if you lost your receipt, 26 months from the date of manufacture.

A little note from the warranty policy page may be of interest to the readers. Galaxy uses a “R” as the first character of the serial number  to denote a refurbished radio. Always check for this when you make or receive a new purchase.

One thing I would change, a small one but an important one, the knobs should have a light colored pointer. The position of the knobs is difficult to see even in decent lighting.

Although priced in the $320.00 to $360.00 retail range, it does have many features for the money. This radio like other Galaxy models seems to be designed by radio operators, not just hatched from an engineer’s desktop. It certainly appears Galaxy did their homework on the user and engineering level.

The features that are desirable are there and work very well. Time will tell if there’s room for a high quality 40-channel AM/SSB base station CB radio in this seemingly 10-meter radio market. A market, ironically that Galaxy was very instrumental in helping to create with their 10–meter line of radios.