How do i tune my cobra 29 - Cobra 29 WX NW ST 40-Channels Base CB Radio

Depends on what you mean by "Tune"

If you are talking about aligning the radio, you need the factory service manual, a watt meter, volt meter and oscilloscope to align the radio.

If you are talking about a peak and tune, that all depends on what you want. If you are just trying to peak it out, the easiest thing to do with out having to know about what you are doing is to turn the modulation to max. In that radio you do that by turning VR4 all the way to the left. That will get you around 20 to 25 watts of modulation.

There is more you can do, but it gets technical. But over all you will be pleased with just the modulation increased.

Some times people have the radio tuned to be run on an amp, which is necessary so that you do not blow up the amp. This involves un-soldering parts and replacing them with other parts to achieve the desired dead key.