Hi MB,
Now that you have proven to yourself that this trick is no real advantage to your "barefoot" transmitting range, let's get down to the real reason it's popular.
Reducing the radio's carrier power is only desirable if you use an external "linear" amplifier. An amplifier has the bad habit of exaggerating your carrier (dead-key) power, and reducing the so-called 'forward swing', or modulated part of your AM transmit signal. Tends to reduce the audio level that comes out of the speaker on the other end.
Reducing the radio's carrier power below the normal proportion serves to compensate for this quirk. If done, right at least. It's a strategy that improves the amplifier's performance, but offers NOTHING at all if you use the radio by itself, or "barefoot", as they say.
Now that you've convinced yourself, I don't need to try.
Best advice I can offer is to remove the resistor and capacitor that went in place of the wire jumper.
Put the wire jumper back, or a new wire in its place.
Odds are this will give you all the radio has to offer on transmit, without changing anything else. Unless they also had you remove or jump around the black plastic rectifier across the circuit board from the final transistor. That jumper should come back off, if this was done. If they told you to pull the diode, put it back. Not the tiny glass one, the larger black epoxy plastic one. Hmmmmm. Now that's a web page somebody (else) should put up. "How to remove the Bling Mod from your Cobra 29/ Uniden PC76/78."
The radio will now show between 5 and 6 Watts of carrier power. Too much to use with most amplifiers, but perfectly legit for running barefoot. And louder to boot, for anyone out there in the distance. Another radio across the parking lot may not show you a big difference that you can tell.
Nothing quite like doing the before-and-after comparison yourself. Makes the result easier to believe, ususally.
73
