Galaxy Saturn Turbo

[Jhawk]

This radio has no receive or tx. It turns on and has audio and the tx light goes on but meters are not moving. Any ideas where to start?

 

[nomadradio]

There is a big difference between a radio that was working okay and just quit, and a radio you have never seen work at all. Have you ever seen this radio work properly?

But I'll guess that this radio was this way when you first saw it, and you have no history of how it was working before it went into a coma.

First thing I ask with this kind of radio is how many attempts have been made to repair it since it first had problems.

For each unsuccessful repair attempt you should expect at least one new, additional problem will be added to the original fault.

Sometimes two.

If three different "techs" have "looked at it" by now, there could be a half-dozen or more separate faults to clean up.

Most-common problem in that radio is with the power supply. It's too small, and wants to overheat. As a bonus, the factory will skip a critical layer of heat-conducting compound under the rectifiers and power-supply pass transistors. It has no protection from overload, and if it fails can shoot 24 Volts into the radio and amplifier.

Tends to blow out a lot of stuff when this happens.

The PLL in this radio has multiple loops and VCOs. Alignment of that section is not trivial. Never have figured out how to do it without a 'scope. The factory instructions for the original RCI2950/2970 are correct for this radio.

A simpler radio with a 40-click channel selector is easier to check for PLL problems than this one. When the PLL in this radio loses its grip on the frequency, it mutes the receiver audio and disables the transmit.

A radio that won't transmit or receive suggests this possibility.

Do you have the basic tools to identify trouble in this kind of radio? A 'scope? Multimeter? Alignment tools?

A radio that powers up and does nothing may or may not have been "screwdrivered" off the air. But it's a common thing to see.

When this happens to a Cobra 29, the procedures are not terribly complicated for getting it to work again.

But this radio offers a larger challenge. A radio with a 40-click channel selector is simpler to analyze. A radio that's run by a computer is just more complex.

I really ought to come up with a pictorial guide to "How to tell if your 2950 PLL is out of lock".

But not today.

The service data for the RCI2950/2970 covers all but the front-panel setup and power supply.

Found here: http://www.cbtricks.com/radios/rci/rci_2970/index.htm

Let us know what tools you have to work with on this project radio.

73

 

[Jhawk]

There is a big difference between a radio that was working okay and just quit, and a radio you have never seen work at all. Have you ever seen this radio work properly?

But I'll guess that this radio was this way when you first saw it, and you have no history of how it was working before it went into a coma.

First thing I ask with this kind of radio is how many attempts have been made to repair it since it first had problems.

For each unsuccessful repair attempt you should expect at least one new, additional problem will be added to the original fault.

Sometimes two.

If three different "techs" have "looked at it" by now, there could be a half-dozen or more separate faults to clean up.

Most-common problem in that radio is with the power supply. It's too small, and wants to overheat. As a bonus, the factory will skip a critical layer of heat-conducting compound under the rectifiers and power-supply pass transistors. It has no protection from overload, and if it fails can shoot 24 Volts into the radio and amplifier.

Tends to blow out a lot of stuff when this happens.

The PLL in this radio has multiple loops and VCOs. Alignment of that section is not trivial. Never have figured out how to do it without a 'scope. The factory instructions for the original RCI2950/2970 are correct for this radio.

A simpler radio with a 40-click channel selector is easier to check for PLL problems than this one. When the PLL in this radio loses its grip on the frequency, it mutes the receiver audio and disables the transmit.

A radio that won't transmit or receive suggests this possibility.

Do you have the basic tools to identify trouble in this kind of radio? A 'scope? Multimeter? Alignment tools?

A radio that powers up and does nothing may or may not have been "screwdrivered" off the air. But it's a common thing to see.

When this happens to a Cobra 29, the procedures are not terribly complicated for getting it to work again.

But this radio offers a larger challenge. A radio with a 40-click channel selector is simpler to analyze. A radio that's run by a computer is just more complex.

I really ought to come up with a pictorial guide to "How to tell if your 2950 PLL is out of lock".

But not today.

The service data for the RCI2950/2970 covers all but the front-panel setup and power supply.

Found here: http://www.cbtricks.com/radios/rci/rci_2970/index.htm

Let us know what tools you have to work with on this project radio.

73

Thank you for the reply. i have a couple of old scopes hp1707b and a tektronix tas 465. i have digital multi-meters and lcr/esr meter and an old hp606a signal generator.
I need a frequency counter (any recommendations?). i have been trying to get my bench up and running for years now. I just replaced the final in my hr2510 thanks to your advice and its working better than ever.
I hope its the pll and not several other issues with my Galaxy. I will research further about the pll. Is there a way to test it?
thanks again for your support it means a lot.
73
J

 

[Jhawk]

There is a big difference between a radio that was working okay and just quit, and a radio you have never seen work at all. Have you ever seen this radio work properly?

But I'll guess that this radio was this way when you first saw it, and you have no history of how it was working before it went into a coma.

First thing I ask with this kind of radio is how many attempts have been made to repair it since it first had problems.

For each unsuccessful repair attempt you should expect at least one new, additional problem will be added to the original fault.

Sometimes two.

If three different "techs" have "looked at it" by now, there could be a half-dozen or more separate faults to clean up.

Most-common problem in that radio is with the power supply. It's too small, and wants to overheat. As a bonus, the factory will skip a critical layer of heat-conducting compound under the rectifiers and power-supply pass transistors. It has no protection from overload, and if it fails can shoot 24 Volts into the radio and amplifier.

Tends to blow out a lot of stuff when this happens.

The PLL in this radio has multiple loops and VCOs. Alignment of that section is not trivial. Never have figured out how to do it without a 'scope. The factory instructions for the original RCI2950/2970 are correct for this radio.

A simpler radio with a 40-click channel selector is easier to check for PLL problems than this one. When the PLL in this radio loses its grip on the frequency, it mutes the receiver audio and disables the transmit.

A radio that won't transmit or receive suggests this possibility.

Do you have the basic tools to identify trouble in this kind of radio? A 'scope? Multimeter? Alignment tools?

A radio that powers up and does nothing may or may not have been "screwdrivered" off the air. But it's a common thing to see.

When this happens to a Cobra 29, the procedures are not terribly complicated for getting it to work again.

But this radio offers a larger challenge. A radio with a 40-click channel selector is simpler to analyze. A radio that's run by a computer is just more complex.

I really ought to come up with a pictorial guide to "How to tell if your 2950 PLL is out of lock".

But not today.

The service data for the RCI2950/2970 covers all but the front-panel setup and power supply.

Found here: http://www.cbtricks.com/radios/rci/rci_2970/index.htm

Let us know what tools you have to work with on this project radio.

73

I am getting ready to attempt the alignment on the Galaxy Saturn Turbo. The instructions say I need:

1. Oscilloscope (50MHz) w a X10 probe √
   
2. Frequency Counter 0-30 M
3. Dummy Load √
4. Digital voltmeter √
5. Audio Generator
6. FM Signal Generator
7. SINAD Meter
8. RF Wattmeter √

I am looking for all the items without a √ after the name. Do you have any recommendations, model #'s etc? I am very excited to be approaching this challenge. If all goes well I will switch out the power supply next.
Thanks
-J