148 gtl cobra cb radio and the rx/tx light stay on

SOURCE: Cobra 148 gtl Low / No receive audio

No audio out / low audio out....This is a constant problem with the COBRA 148 gtl....to get a good level of volume replace the
electro caps ...start around the two speaker wires and work back from there. I'm in the process of rebuilding a 148 gtl and have found caps that are leaky and dried out...after replacing nine the volume went up to a good level...now i need to fix the distortion
and background hash. Did you know that there are many posts
on FIXYA about this same problem I.E. great TX , great PA but poor , or no audio out. these sets have been made in sevetal countries...The sets made in Taiwan or China have poor quality
front panel pots (the carbon track is micro thin and simply wares through to the material the track is printed on) This has the same effect as removing a wire from a pot I.E. no audio. The good news is that 99% of parts in the radio are freely available and that includes the front panel controls. ONE WONDERS IF THE SET IS WORTH THE EFFORT !!!

CHEERS GUYS / GIRLS.

Iron

• 3018 Answers
• Posted on Nov 09, 2011

SOURCE: schematic diagram of cobra 148 gtl cb radio china made

• Locate the MB8719 chip that is right behind the channel selector. Wire a SPST switch from pin 10 to ground and another from pin 11 to pin 12.
  

• Schematic http://minus.com/my8tfHQMD#1

• Channel Chart
  

• Position 1: sw1 down, sw2 down
• NORMAL CHANNELS
  

• Position 3: sw1 up, sw2 up
  

• 1=27.605 6=27.505 10=27.555 14=27.605
  
• 2=27.455 7=27.515 11=27.565 16=27.475
  
• 3=27.465 8=27.535 12=27.585 20=27.525
  
• 4=27.485 9=27.545 13=27.595 23=27.575
  
• 5=27.495
  

• Position 4: sw1 down, sw2 up
  

• 1=27.605 11=27.725 21=27.855 31=27.955
  
• 2=27.615 12=27.745 22=27.865 32=27.965
  
• 3=27.625 13=27.755 23=27.895 33=27.975
  
• 4=27.645 14=27.765 24=27.875 34=27.985
  

Iron

• 3018 Answers
• Posted on Nov 29, 2011

SOURCE: cobra 148 gtlcobra 148 gtl DX

• Hi, here is your users manual http://minus.com/m8geTULWN#1 just click "download" if you want a copy of it. I have a copy of the service manual as well. Let me know if you want a copy.

• Hope this helps.