Galaxy Saturn transformer

[ChrisDel157]

One of my original problems with this radio, Saturn (nonturbo) What's the frequency counter wasn't working correctly. After putting a set of caps and a new voltage regulator in the circuit board I was checking for voltage and according to CB tricks I should have 13.8 volts going into it. I don't, Which led me to check voltage at the rectifier and the AC voltage coming in. I'm only getting 10 V DC out of the rectifier, Can somebody tell me if this is accurate? Just as a back story I'll add that when I bought this radio it had a European 220 plug And the person running it had a 220 adapter to 110. I ran it like that if you times and then converted it to A110 plug.my thought is the transformer is weak but not bad, and Causing a voltage drop which leads to erratic frequency displays from the frequency counter. The most unfortunate part of this is I bought a stock of radios from a person that Is now deceased.(Rest in peace Mike)

 

[BJ radionut]

Does anyone have any thoughts?
Seems like this has come up before, but could not find a reference to this specific issue.
All the Best
Gary

 

[Mark Malcomb]

Hmm. 50 HZ or 60 HZ. My damn clock ran 10 Min slow an hour in Europe.

 

[TM86]

Here's what I got.

Let's start off with a disclaimer. I know absolutely nothing about this radio except what the original poster stated.

Since the radio previously had a "European" plug and was run off an "adapter" I'm going to make the assumption (mistake #1 on my part) that the radio was built to run on 220 Volt power. So cutting off the European plug and attaching one designed to plug into an American socket may not have been the best approach.

Since the transformer is now seeing half the voltage it was designed for on the input side, it's putting out half of what it should on the output side.

But that's only if my assumption is correct and the radio doesn't have one of those power supplies that doesn't care what you feed it as long as it's between 90 and 240 volts.

 

[Lkaskel]

I might be able to assist a little here. I have, on my bench, a Galaxy Saturn. To be sure that we are talking about the same radio, what board does your radio have? Mine has the EPT360010A. Also, mine has a switching power supply in it. I can post a pic if needed.

 

[nomadradio]

it had a European 220 plug And the person running it had a 220 adapter to 110. I ran it like that if you times and then converted it to A110 plug.

The 220 Adapter stepped your 120 Volt outlet voltage up to 240 Volts, more or less. That's what the transformer in your radio is built to accept from the line cord.

The reading you get is about half what it should be. If you feed 120 Volts into a 240-Volt transformer, this is what you'll see. About half the voltage you should get. Changing the plug only keeps you from hooking it to the converter. The one that made it work.

Seems to me the transformer in that radio is built for either 120 or 240. Just have to feed the line voltage into the correct two wires. Pretty sure the low-voltage wires exit one side of the transformer, and the line-voltage wires are on the other side. If you have three wires coming out that end, this is good news. This means the third wire that's not connected is your 120-Volt input. The wire from the power switch should be moved from the 240-Volt wire where it's connected now, to that third wire.

And if there is no third wire hanging loose, you need to go back to your converter.

73

 

[ChrisDel157]

I might be able to assist a little here. I have, on my bench, a Galaxy Saturn. To be sure that we are talking about the same radio, what board does your radio have? Mine has the EPT360010A. Also, mine has a switching power supply in it. I can post a pic if needed.

A pic might help me here... I hope I can see the rectifier too. Thanks bud

 

[ChrisDel157]

The 220 Adapter stepped your 120 Volt outlet voltage up to 240 Volts, more or less. That's what the transformer in your radio is built to accept from the line cord.

The reading you get is about half what it should be. If you feed 120 Volts into a 240-Volt transformer, this is what you'll see. About half the voltage you should get. Changing the plug only keeps you from hooking it to the converter. The one that made it work.

Seems to me the transformer in that radio is built for either 120 or 240. Just have to feed the line voltage into the correct two wires. Pretty sure the low-voltage wires exit one side of the transformer, and the line-voltage wires are on the other side. If you have three wires coming out that end, this is good news. This means the third wire that's not connected is your 120-Volt input. The wire from the power switch should be moved from the 240-Volt wire where it's connected now, to that third wire.

And if there is no third wire hanging loose, you need to go back to your

 

[ChrisDel157]

Here's what I got.

Let's start off with a disclaimer. I know absolutely nothing about this radio except what the original poster stated.

Since the radio previously had a "European" plug and was run off an "adapter" I'm going to make the assumption (mistake #1 on my part) that the radio was built to run on 220 Volt power. So cutting off the European plug and attaching one designed to plug into an American socket may not have been the best approach.

Since the transformer is now seeing half the voltage it was designed for on the input side, it's putting out half of what it should on the output side.

But that's only if my assumption is correct and the radio doesn't have one of those power supplies that doesn't care what you feed it as long as it's between 90 and 240 volts.

It runs 110 and 220. I know it's connected properly because the output is still the same from 220v and now 110v on the output of the transformer to the rectifier. Output of 10volts. I was hoping for 13, is that wrong?

 

[ChrisDel157]

I might be able to assist a little here. I have, on my bench, a Galaxy Saturn. To be sure that we are talking about the same radio, what board does your radio have? Mine has the EPT360010A. Also, mine has a switching power supply in it. I can post a pic if needed.

Could you test the output at the rectifier? I have 10volts. I think it needs to be 13? At least I hope so

 

[TM86]

It runs 110 and 220. I know it's connected properly because the output is still the same from 220v and now 110v on the output of the transformer to the rectifier. Output of 10volts. I was hoping for 13, is that wrong?

Should probably be a bit higher at the rectifier and then at 13.8 out of the regulator. No idea how you're getting the same voltage out of the transformer on 110 and 220. But like I said, I know nothing about this radio. All I've got is speculation, so I'll shut up about it now.

 

[nomadradio]

The output from the rectifier bridge is your UNregulated DC voltage. Should be 20 to 22 Volts. This feeds into the voltage regulator circuit, stepping it down to a steady 13.8 Volts, or whatever the trimpot is set to.

The reason you show 10 Volts from the rectifier is that you're only feeding half the line voltage it needs, since it's wired for a 240-Volt wall outlet.

You can't use the exact same transformer hookup for both 120 and 240 Volts. Have a look at the side of the transformer that has the wires leading to the power cord. If there is a third wire cut off short visible, this is your 120 Volt hookup. If there is no third wire, you have a 240-Volt only transformer.

73

 

[BJ radionut]

Chris: When you removed the Euro 220 volt plug...did you note how it was wired? Specific to the Color code of the wires and how they came off the specific pins?
Do you have any pics of all of this?
Like Nomad, going from Euro 220 version to US 120 set-up can be tricky.
If this were a little more modern device, the new switching supplies can adjust automatically. Other rigs had a switch to make this change. Others require placement of the correct wires on the correct pins to get the correct voltages.
I am saying can you help us out with more info...internal pictures, original plug/adaptor pictures, etc..?
Presently we are like you shooting in the dark on the configuration of that power supply.
I am not familiar with that rig, but pictures of the old configuration and good, clear internal pictures would help a BUNCH!
All the Best
Gary

PS: Transformers do not "normally" get weak...they work or they don't...yes windings can short, but that would normally create a high current or fuses blowing situation, etc. Wild voltage swings, etc.
When a conversion like this happens, the correct wiring of the input to the transformer's primary determines the output of the secondary windings.

 

[ChrisDel157]

Chris: When you removed the Euro 220 volt plug...did you note how it was wired? Specific to the Color code of the wires and how they came off the specific pins?
Do you have any pics of all of this?
Like Nomad, going from Euro 220 version to US 120 set-up can be tricky.
If this were a little more modern device, the new switching supplies can adjust automatically. Other rigs had a switch to make this change. Others require placement of the correct wires on the correct pins to get the correct voltages.
I am saying can you help us out with more info...internal pictures, original plug/adaptor pictures, etc..?
Presently we are like you shooting in the dark on the configuration of that power supply.
I am not familiar with that rig, but pictures of the old configuration and good, clear internal pictures would help a BUNCH!
All the Best
Gary

PS: Transformers do not "normally" get weak...they work or they don't...yes windings can short, but that would normally create a high current or fuses blowing situation, etc. Wild voltage swings, etc.
When a conversion like this happens, the correct wiring of the input to the transformer's primary determines the output of the secondary windings.

Chris: When you removed the Euro 220 volt plug...did you note how it was wired? Specific to the Color code of the wires and how they came off the specific pins?
Do you have any pics of all of this?
Like Nomad, going from Euro 220 version to US 120 set-up can be tricky.
If this were a little more modern device, the new switching supplies can adjust automatically. Other rigs had a switch to make this change. Others require placement of the correct wires on the correct pins to get the correct voltages.
I am saying can you help us out with more info...internal pictures, original plug/adaptor pictures, etc..?
Presently we are like you shooting in the dark on the configuration of that power supply.
I am not familiar with that rig, but pictures of the old configuration and good, clear internal pictures would help a BUNCH!
All the Best
Gary

PS: Transformers do not "normally" get weak...they work or they don't...yes windings can short, but that would normally create a high current or fuses blowing situation, etc. Wild voltage swings, etc.
When a conversion like this happens, the correct wiring of the input to the transformer's primary determines the output of the secondary windings.

Here is the transformer (factory 110v and 220v) and here is the wiring pic from when I bought it. I don't remember the AC out to the rectifier, so I'll check it tonight and post back. I am getting 10volts out of the rectifier and 11.3 at the 35v capacitor just after it (which I think is strange). God I love this radio... lol

 

[ChrisDel157]

Chris: When you removed the Euro 220 volt plug...did you note how it was wired? Specific to the Color code of the wires and how they came off the specific pins?
Do you have any pics of all of this?
Like Nomad, going from Euro 220 version to US 120 set-up can be tricky.
If this were a little more modern device, the new switching supplies can adjust automatically. Other rigs had a switch to make this change. Others require placement of the correct wires on the correct pins to get the correct voltages.
I am saying can you help us out with more info...internal pictures, original plug/adaptor pictures, etc..?
Presently we are like you shooting in the dark on the configuration of that power supply.
I am not familiar with that rig, but pictures of the old configuration and good, clear internal pictures would help a BUNCH!
All the Best
Gary

PS: Transformers do not "normally" get weak...they work or they don't...yes windings can short, but that would normally create a high current or fuses blowing situation, etc. Wild voltage swings, etc.
When a conversion like this happens, the correct wiring of the input to the transformer's primary determines the output of the secondary windings.

Also, thank you for your help here. It is much appreciated! Hope you have a good 4thanks!