Class C amps driven to saturation

[linearone]

http://www.youtube.com/watch?v=uPDPwZbq2Go

Driving the class c amp into saturation is the most efficient way to run it

cbers have been saying this for years

 

[Master Chief]

Efficient, but certainly NOT CLEAN, which is the argument against driving the hell out of a class-c amp.

Linear Technology SPICE Software:
http://www.linear.com/designtools/software/index.jsp

 

[freecell]

"Driving the class c amp into saturation is the most efficient way to run it"

yeah, and where fidelity (freedom from distortion) is of no concern class c operation is restricted to rf transmitters that are not amplitude modulated with asymmetrical (voice) audio sources because of the extremely high levels of distortion superimposed upon the signal and why they are best suited for CW and FM operation. stackpole saturation of and by itself creates distortion.

and while we're on the subject of "efficiency", (which is the ratio of output signal power compared to the total input power) the efficiency is reduced once the amount of power input to output (db=10log(POut/PIn)) causes the gain of the devices used to decrease, regardless of operating class.

"cbers have been saying this for years"

"cbers" say some stupid things.

 

[Beetle]

Okay, so much for the amplitude domain. Now how about something in the frequency domain (spectrum analyzer) showing the actual spectra of the input signal vs. the output signal.

 

[novakor]

I have some local 11m guys here ..........some sound great with or without amp on. Although some sound great until amp is on then there distorted even though there running either class b or ab bais amps. I try to tell them they sound distorted and they claim that were just too close and the signal would sound better long distance. Now maybe i'm wrong but i always thought poop in poop out and your signal isn't going to sound any better as it travels. Am i wrong?

 

[FL Native]

i use to hear that all the time. the excuse im too close or your distorted cause your close.

not sure were that myth got started unless the radio getting the interference was getting rx overload wich sounds fisshy to me.

 

[mackmobile43]

i use to hear that all the time. the excuse im too close or your distorted cause your close.

not sure were that myth got started unless the radio getting the interference was getting rx overload wich sounds fisshy to me.

I've tested class-c amps from one radio listening to that radio on another not three feet away and I hear none of that distortion on ssb/fm or am.

 

[BOOTY MONSTER]

forgive me for im just a duck egg at this level but what are they determining to be the saturation level ? the 100 watts toshiba specs a 2879 at ? the maxium power befor the thing becomes minature BBQ grill ? the 300-400 watts that fat-force or x-dave claim for a 2879 ? if it is 200 or 300 or 400 watts are they deducting the off frequency watts that the contact you have never hears but others on other channels hear as bleed over ? i notice the test was done at 1 MHz for 1 milisecond . since i talk around 27 MHz and for many whole seconds at a time (sometimes over a whole min !!) how does this apply to someone such as myself ?

 

[BOOTY MONSTER]

forgive me for im just a duck egg at this level.............
how does this apply to me at 27 MHz ? also , i dont think i could key a mic for just 1 hundredth of a second let alone 1 milisecond . is he using morse code for the signal ? am ? ssb ? how would using a modulated am or ssb signal @ 27 MHz affect his findings ? being the duck that i am im suspecting that where and how he is talking/transmiting is a different animal from what i do and that using the same rules/criteria would have different results . please remember im a duck at theis level so try to be kind if im way off base . i know i dont know my anus from a hole in the ground at this level......but i do have questions .

 

[BOOTY MONSTER]

thanks solitude . i thought i was editing my previous post but i must have clicked the wrong button and you posted while i was apparently making a different post . i just run a lil ab filtered 225 anyway .

 

[bigred222]

It just means that everyone on 6 channels above and below you will be able to here how efficient your class C amp is for a whole minute.

Very well put.
HAHAHAHAHAHA