Galaxy DX949 Question

[MountainDweller]

Hello,

I have a circa 2002-3 model Galaxy DX949. At some point today the unit ceased modulating signal from the microphone, and the talkback likewise. The roger beep still modulates and sounds via the talkback as normal.

I tried two different microphones with the same results. If I cup the microphone to my mouth and shout hard the modulation will raise up to about 40-50%.

Thoughts?

Thanks for reading!

Best,

Nathan

 

[Robb]

Can you hear the receiver?

 

[Slowmover]

Can you the receiver?

I’m pressin’ the LIKE button . . but I don’t know why.

 

[nomadradio]

Two likely culprits come to mind. First would be a bad mike-gain control. The roger beep is "downstream" from it and would not be affected.

Next would be a 1uf 50 Volt (yes) electrolytic cap C153. If you have a spare one handy, or even a cap with a bigger capacitance, up to about 100uf, holding the leads of the cap up to contact the two foil pads under C153 would temporarily restore mike audio. Kinda clumsy to hold both leads of the cap against those two foil pads, while keying the mike, but it's a quick-and-dirty test of this little cap. When C153 fails, it usually becomes an open circuit. Touching the leads of the 'test' capacitor to the two foil pads puts it in parallel with the bad cap and restores the lost audio gain.

And if this makes no difference, C153 is not the cause.

73

 

[MountainDweller]

Can you hear the receiver?

Hi,

Yes, it is receiving as normal.

Best,

Nathan

 

[MountainDweller]

Two likely culprits come to mind. First would be a bad mike-gain control.

Thank you!

Now that you mention it the gain control feels off, maybe too many cycles of the RB switch have caught up. Can this be bypassed to test it?

Best,

Nathan

 

[Handy Andy]

Click on this link...

http://www.cbtricks.com/radios/galaxy/index.htm

See if thats' got your radio...

Then you can look into starting on the Mic problem...

When you have "Weak audio" and yet the RB works - and you say you have to cup the mike and you get 40 to 50% - not sure what that means unless you've got a meter working in it somehow - the thing does have a MOD switch so there ya' go on that...thanks for finding that - it helps us in finding out the rest of this...

The Rest of This...

What occurred or happened when you found no / weak audio?

• One night talking to a friend - the mic quits...
• Had it sitting for several years,
• Cleaned out the Garage - found my car and the Radio and since the price of gas went back up...
• Someone dropped kicked this wheel chock to the side of the road so I took it home fed it some Radio Shack Batteries and woke up one day to find it working - to a point...

Was work done to the Radio?

You have two mics, so that tends to rule out the likely-ness of having a bad element by chance...

So it tells me by your opening statement...

I have a circa 2002-3 model Galaxy DX949. At some point today the unit ceased modulating signal from the microphone, and the talkback likewise. The roger beep still modulates and sounds via the talkback as normal.

The sad thing to tell you is the radio was made in an era that now, enough time has elapsed - where the age of the parts used inside it - especially those little pesky blue and black - grey striped thingys...

Might have some work ahead of you...
This is what @nomadradio - sections' he's talking about...

That black rectangle thing with "4558 double-D" is the Mic amp and TX - Power Good "decider",
your Chip writing may differ but it should still have "4558" on it...
Located inside, with the front panel facing you, right bottom corner side...
- about 1/4 of the way back from the front.
Those "pesky" caps are in front of it, blocking this shot...
Those brown discs' are caps too
- along with that Yellow bodies dipped tantalum with 2.2uF written on it.​

Go to that link, find your radio - click around the Galaxy radios section - there are a lot of radios that are all nearly identical to each other. It's like buying a Chevy, maybe a different style but it's still all the same stuff inside them...