Cobra 29 Dynamic

[God1234]

Hiya Everybody,

Quick question here. I have a cobra 29 hooked up to a 3 pill linear. I have the Dynamic pretty much turned all the way down due to being nervous of frying my amp.

My question is will turning the dynamic up do any damage to the amp Ie. raise my dead key or am i good to go and can crank that thing.

Thanks

 

[God1234]

Buler Buler

 

[Sideways]

The mic gain doesn't change the deadkey. It will change pep. I doubt you have to worry bout frying your amp, as long as everything on your install is good.
Get a buddy to listen to your audio on another radio, and turn the mic up till it starts to get distorted. Mark that spot on your radio, then you'll know how far you can go before it starts to sound bad. Kind of the down n dirty way of doing it, but it works.
Depending on if your radio is stock or not, and youre using a noise canceling mic. Should be able to run the mic gain between 12 and 3 o'clock with no problems.

 

[God1234]

The radio is stock only the modulation pot was turned up. The mic is stock as well. Any way you can give me a quick breakdown on PEP?

 

[Sideways]

The radio is stock only the modulation pot was turned up. The mic is stock as well. Any way you can give me a quick breakdown on PEP?

P.E.P. peak envelope power is the peak or highest amount of power your radio hits while modulating, talking into the mic.
For example; you radio is stock with the mod pot turned up. It probably has a 4 watt carrier or deadkey, and swings to 16watts peak, or pep when you talk into the mic. Turning the dynamike gain up or down will change pep.

 

[God1234]

How many watts do you think I can drive that amp with before I do any damage? Am I correct in saying that the swing to 16 watts should not cause any damage?

 

[Sideways]

How many watts do you think I can drive that amp with before I do any damage? Am I correct in saying that the swing to 16 watts should not cause any damage?

Don't know what amp you have, but as long as you are getting good loud and clear reports, and the amp isn't too hot to touch, you should be good.
Don't know what the output of your radio is, was just using 16 watts as an example, but it should be somewhere in that neighborhood.
Get a good noise canceling mic, astatic 636, rk56, they have more clear audio.

 

[543_Dallas]

3 pills can be finaky. I don't know how the amp is built but the 4 watt carrier from your radio is likely too much. You can turn the variable on the amp down to reduce the output to a safe level but in time the variable will probably fail. Do you have a watt meter to check the output of the amp? If not there's nothing we can do to help you short of guessing.

 

[God1234]

I have a watt meter however it is only rated for 100 watts

 

[543_Dallas]

I have a watt meter however it is only rated for 100 watts

75-100 watts is the max you should key that amp at. Even though you can't measure the peak power with a 100 watt meter you can check your carrier. Turn the dynamic all the way down to test the power out of the amp. If it buries the 100 watt meter do not keep using it that way.

 

[God1234]

The mic gain doesn't change the deadkey. It will change pep. I doubt you have to worry bout frying your amp, as long as everything on your install is good.
Get a buddy to listen to your audio on another radio, and turn the mic up till it starts to get distorted. Mark that spot on your radio, then you'll know how far you can go before it starts to sound bad. Kind of the down n dirty way of doing it, but it works.
Depending on if your radio is stock or not, and youre using a noise canceling mic. Should be able to run the mic gain between 12 and 3 o'clock with no problems.

I plugged the cb into my pa system and used it as an external speaker, so i could hear how the radio sounded. When i turned the amp and the dyna up it seemed to for lack of a better word lag? when turned down it sounded better.

I went back in and turned vr4 back down. Did the same thing and it sounded much better when i turned the dyna up along with the amp.

My question is, is the sound I am getting out of my pa accurate to how my radio sounds on air?

75-100 watts is the max you should key that amp at. Even though you can't measure the peak power with a 100 watt meter you can check your carrier. Turn the dynamic all the way down to test the power out of the amp. If it buries the 100 watt meter do not keep using it that way

I went and got a new meter. (radio shack 2000 watts) I will report back tomorrow.

 

[Sideways]

My question is, is the sound I am getting out of my pa accurate to how my radio sounds on air?

No it is not.

Would help to know what amp your running also?

 

[Robb]

The number #1 cause of amp failure?
Over-driving the input.

Avoid this by using slightly less watts than the recommended wattage.


The next most common failure?
Over-heating it with a long keydown.

Shorten the keydown time length and put a fan on it.
Both.

The next signifucant cause of failure?
Feeding it too much voltage.

If you need more watts, get a bigger box. Otherwise, over volting it will just shorten its life.