Sounds like a faulty "MIC" or bad knob inside radio. Your radio may have too much gain. Try using a ordinary straight "MIC" . Some radios are tuned to operate with a straight mic. If you use a "Power Mic" it may be too much gain and cause a squeal. Impedance of the mic must be matched. If its a 500 ohm use only 500 ohm. If its an 1000 ohm use only 1000 ohm "Mics". A straight factory Cobra mic(Coffin mic) has gave me the best performance I have ever used on a Cb radio. I can talk 50 miles on straight mics.
Answers & Comments
Hello,
Do you have talkback on your radio? If you do then turn it off when you want to turn the mic gain up because this can cause feedback.
Regards, Tony
Sounds like a faulty "MIC" or bad knob inside radio. Your radio may have too much gain. Try using a ordinary straight "MIC" . Some radios are tuned to operate with a straight mic. If you use a "Power Mic" it may be too much gain and cause a squeal. Impedance of the mic must be matched. If its a 500 ohm use only 500 ohm. If its an 1000 ohm use only 1000 ohm "Mics". A straight factory Cobra mic(Coffin mic) has gave me the best performance I have ever used on a Cb radio. I can talk 50 miles on straight mics.