Dx959

[Wolfman 426]

Hello everyone I have an old Galaxy DX 959 and it keying up on its own where should I start looking to fix this problem thank you

 

[Eldorado828]

Rule out the microphone first, unplug it?

 

[Shadetree Mechanic]

A mic wired up for a different radio can cause it to key when plugged in. I accidentally ruined a Midland that way one time.

 

[nomadradio]

Does it do this with the mike unplugged?

73

 

[Wolfman 426]

Yes it does not matter if the mic is plugged or unplugged

 

[nomadradio]

This radio has a switch transistor that feeds power out to pin 4 of the mike socket, but only while it's keyed. Shuts it off when receiving. One leg of this transistor connects to pin 3. If your radio is older, this will be on a tiny circuit board with three wires going to the mike socket, and a fourth wire that feeds power to it.

The 3 wires go to pins 1 (ground) 3 (transmit) and 4. If you cut or unhook the wire to pin 3, this will tell you if the fault is in this switching circuit. It's meant to feed 8 Volts DC to pin 4 only while it's keyed. Lets you power a fancy mike with a preamp, or echo or whatever without the need for a battery.

If removing the pin 3 wire to this tiny board doesn't fix the problem, I'll be surprised. One way to find out.

And if your radio is a latest-and-greatest version, all this stuff will be combined on the pc board that hosts the mike socket. Don't know what year they made that change.

And there is another fault that comes from the side-mike socket coming loose, spinning and shorting to a diode on the main circuit board. Knowing which decade the radio is from helps narrow down how it's laid out inside.

73

 

[Wolfman 426]

Thank you very much for the great info have a good day sir.