Thursday, April 16, 2009

Cobra 148 GTL Audio and Power Mods.

A simple way to really increase the audio of a Cobra 148 GTL CB radio is to find R126 and jumper it. It is a 10K ohm resistor about 1" to the LEFT of the MIC jack.
Do NOT remove the TR25 Mod Limiter on this radio, as it will sound like crap later.




To add extra channels install 2 switches in the radio, or use the HI/LOW and BRT/DIM switches on the front.
My friend wanted 2 new switches on the rear, so thats what I did with this radio.

You will need 2 SPST switches.

Find the PLL IC and find pins 10, 11 and 12 and the large Ground trace near pin 10.

Wire Switch 1 to Pin 10 (pin goes to nothing) and also to GND pad.
Wire Switch 2 to pin 11 and pin 12.
Be very careful to not use too much heat on the IC pins, and they are fragile and you can damage the PLL chip. Use a 30watt max solder pencil.

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