Hi all.
Picked up this Uniden 68 and used it for a couple days. Its a used radio. Got it for pretty cheap. The other day the RX died. So I took it out of the truck and put another radio in the truck. Same mic and power cord. Anyways, I've got this Uniden home and injected a signal into the SO239 with a sig. gen. and nothing. So I spent some time checking voltages on TR's encluding the first IF and the reverse diodes as that normally where I find these types of problems and all tests fine. ???
I decided to bump up the power, so I injected mv of signal instead of uv of signal and I can hear it RXing. The more I input the louder it gets, volume and squelch controls work as they should as long as I'm injecting the higher amplitude of signal. Also the filters/cans all adjust the signal up and down so they seem to be doing what they should.
Please let me know if I'm thinking on the right line here... If I can RX with more amplitude, than this confirms that all TR's and filters (455 and 10.7) are working as they should. And the issue has to be a bad connection somewhere. All caps should be ok too, right?
So am I think correctly on this? What can I be missing? I've spent a few hours going thru the board touching up solder joints and flexing the board and no changes. Please help me to understand what "MIGHT" be a place to look for an issue like this.
BTW, if I inject a AF signal into the audio chip all works as it should so this is telling me that the problem is between SO239 and audio chip. Right?
Thanks for any help. I'd say I should stop buying used CB's for cheap but I just cant help myself. Ha.
Jerry...
Picked up this Uniden 68 and used it for a couple days. Its a used radio. Got it for pretty cheap. The other day the RX died. So I took it out of the truck and put another radio in the truck. Same mic and power cord. Anyways, I've got this Uniden home and injected a signal into the SO239 with a sig. gen. and nothing. So I spent some time checking voltages on TR's encluding the first IF and the reverse diodes as that normally where I find these types of problems and all tests fine. ???
I decided to bump up the power, so I injected mv of signal instead of uv of signal and I can hear it RXing. The more I input the louder it gets, volume and squelch controls work as they should as long as I'm injecting the higher amplitude of signal. Also the filters/cans all adjust the signal up and down so they seem to be doing what they should.
Please let me know if I'm thinking on the right line here... If I can RX with more amplitude, than this confirms that all TR's and filters (455 and 10.7) are working as they should. And the issue has to be a bad connection somewhere. All caps should be ok too, right?
So am I think correctly on this? What can I be missing? I've spent a few hours going thru the board touching up solder joints and flexing the board and no changes. Please help me to understand what "MIGHT" be a place to look for an issue like this.
BTW, if I inject a AF signal into the audio chip all works as it should so this is telling me that the problem is between SO239 and audio chip. Right?
Thanks for any help. I'd say I should stop buying used CB's for cheap but I just cant help myself. Ha.
Jerry...
