GP300 tx problem

[Sarge, USMC]

I'm getting a whack of these units coming in that I don't know how to deal with. Tx fine.....until you squeeze the doggone thing, then the tx audio is snap, crackle, pop. It's all over the place. Anyone seen this and/or know how to deal with it?

[Bigred]

Just general dirt and oxidation inside. Flexing causes the VCO to jump around. Common in a lot of portables.

Take radio apart. Look at PCB. There are numerous spots and little fingers where grounds connect to the back frame and the top shield.
Some spots will be black and cruddy. Clean all ground contacts with a pencil eraser and contact cleaner. HT1000's I reflow the solder
on the ground lands of the PBC. I use a little stabilent 22 to protect and restore ground connections. This will knock the fire out of the crackle.

[Sarge, USMC]

Thank you. Been there, done that.............

[Bill_G]

Thank you. Been there, done that.............

We call it the crunchies at our shop. Someone puts a gorilla grip on the housing, and the tx audio sounds horrible. We do the work already described - get those grounds clean. But, if that didn't work for you, then start looking for loose shields. We use a heat gun and reflow each one.

Check the mic and flex too. Case and point - years ago a small police agency with 100% portables was complaining about range. They could not cover their township like they used to. All transmissions were noisy. The tech in charge went through everything twice and couldn't find a problem. I responded, listened to a few calls, took apart their speaker mics, lubed the seams of the mic housing, and the serviced the grounds in the portables. Bingo! They were listening to mic creaks and crunchies, and calling it coverage.