Would like to know the proceedure for mod limiter clip and mod peak, seems to have plenty of receive with the RF Gain.

Dustin turn the rf gain knob all the way to the right also make sure the much gain is atleast half way. If.your still not hearing anything than you need to have the antenna tuned. Swr. Is very important do not use the radios meter to set this it is done with an external swr meter.

AM will only give to about 40W without modulation. This is the RF Carrier required for the AM Mode. This is because the RF Carrier is modulated by your voice, and when speaking into the mic, the voice peaks will increase the output to about 80W if not measured with a peak reading wattmeter. All radios will work like this in AM.

SSB requires audio to get any RF output. If your microphone is defective, or your MIC GAIN control is fully counter clockwise, you will get no output power when you speak into the mic. Output power, if not measured with a peak reading wattmeter will bounce to about 80W on voice peaks.

MOST wattmeters are not peak reading.

Yes you can turn up VR pot inside to recieve max level but will cause noise to be max too. I don't rightfully remember which one does it but I'll refer you to Defcom cb radio mods for a spec sheet
or Snakedoctors cb radio mods google site. Go to these radio mods sites on Google search and type in radio model. It will tell you what Vr inside to turn up RX of RF gain. Turn up modulation and written instruction if you are handy with solder gun how to change a resistor or cap to make it more sensitive recieve. How to replace final stage and resistors to 1/2 watt size for 6 more watts output and spread coils 1/8 inch apart like a comb for 100% microphone loudness or swing output. say 3 watts to 40 watts output. More windshield wiper swing in meter makes loud voice and extends range with Power final boost. Most people prefer to keep a mobile at around 11 watts swing to 45 watts.(but on generic radio meter will show 2 to 5 watts-its not accurate just a cheap indicator you are forward swing). Even though factory says 4 watts FCC hogwash. They come tuned from Cobra with 11 watts to 14-22 watts.Cobra really peaks them babies so competition doesn't beat them out like new louder radios made by Galaxy 55. Even though law says blah blah (corporations bend it)sales pitch Galaxy very heated with Cobra on the game(rich can do what they want)Galaxy is 20 watts factory with big promise to 40 watts dual finals. So Cobra updated and said "screw it we will break the law too" Now Cobra is loud as ever and offering their own super mod versions and dual final radios with 45 to 65 watts output with ranges on SSB & USB of 1500 miles on a strong good outdoor antenna.

if a good peak and tune is done you shouldn't have to clip it .I have no information as to what to clip anyway.

If the radio is made to be sold only in the US then the phase lock loop is disabled when your are trying to transmit out of the US band edges. Try looking up a MARS circuit mod for this model and it amounts to only clipping one end of a diode to enable the transmitter on all frequencies.

The 29 has a built in SWR meter--check the match to make sure it is below 2 (lower the better).

The radio can be peaked for better than factory audio.

If the squelch is up too high you will not hear people below a certain signal level---in your case set it so you hear who you want to and not jokers.

RF gain lowers signal the radio sees for receive.

The stock mic will work but make your voice somewhat flat sounding---a power mic or having the mod limiter removed will make the radio and your voice louder.

Let me know if questions.

The RF limits the signal strength you radio receives. After setting the RF to limit excessive signals, then set your squelch up until the noise is gone. There are some areas which have high RF background noise so adjustments are made often while driving around. Use the ANL (automatic noise limiter) and other features also to control the noise.

turn down the mic gain until its not distorted any more.

Also, If this radio has been peaked and tuned, some one may have clipped d10 with is the modulation limiting diode. When you clip it, it disables it. This may have been done instead of just turning VR4 all the way down, which turns the modulation up, but still limits it by a hair. A lot of the time clipping d10 is fine and doesn't get you sputtering, but if it does you need to connect it and just turn VR4 all the way down.

Most likely you have they dynamike to high. About 1 or 2 o'clock should do it.

Also if you are using a power mic, that is too high.

A lot of times it's the mic its self and not the Gain that makes you loud.

If you want to be loud, get your self a skythumper noise canceling mic. And put your mic gain around 1 or 2 o'clock.

nearly all problems are caused by poorly tuned or untuned antennas. a good antenna system with a cheap stock radio will out perform a great tuned radio with a bad antenna system any day of the week. if you dont believe me, check the firestik antenna website's tech notes. or wilson's tech notes.

Here is a link to the Phantom CB's seb site, you can click on the brand of radio you want to peak, in you case, Cobra. Then follow through the chart to the Cobra 29 LTD Classic under the Cobra power mods, which tells you what to adjust and changes that can be made. Only one suggestion I have before you start, where it says to cut D11, don't, only turn up VR-4 for your modulation. That is the only thing I don't like with their instuctions is telling people to cut the modulation limiter. You can get full modulation by turning up the potentiometer, and if you cut the limiter, sometimes it will over modulate.

http://www.714xpress.net/714mods1.html


You need an inline power meter to peak the radio out. This is the quick and dirty way to peak and tune a radio. To properly align a radio, you really need an oscilloscope and other related test equipment.


If you have more questions, don't hesitate to post here or email me at [email protected]. I can't promise I will have an answer to all questions, but I will do the best I can to help.


Dean Pitts
Rollin CBs