Low RX & Squeal on 148

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Dead Key
Dead Key
Posts: 39
Joined: Wednesday 26th Mar 2008, 20:07
Location: SF Bay Area, California

Low RX & Squeal on 148

Post by Shadow » Thursday 28th Jan 2010, 18:18

Radio Make and Model: Cobra 148 Soundtracker
PCB Number: 4A1099A Rev.08
PLL Number: MMB8719
Test gear available: power/SWR meter, multimeter, ext. freq. counter, hammer
Symptoms: low RX. The wires from the RF Gain knob are sensitive to the touch. When I touch them, the RX increases (the more fingers, the more RX), and sometimes it produces a very loud squeal. Immediately after TX, the RX gradually increases to it's normal (low) level over about a couple seconds.

What is working: Everything else

What has been tried:
- Used a different microphone
- Checked RF Gain potentiometer
- Replaced wires
- Checked solder points at knob and board
- Ancient CB radio healing dance

Did it suddenly happen ?: Radio was acquired like this.
Anything else that may be of help?: Radio is unmodified

Any help is appreciated :) I'm troubleshooting this for a friend.

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