Typically ALC is used in the ham world. Keeps the finals from 'flat-toping'. Especially common when running a external linear with a transciever, gives feedback from the amp to the low level transciever circuit that the output is getting too hot and to please cool it a bit.
Yeah I thought of ALC too but it is not audio derived and is only for the final. An audio limiter (most often a compressor, really) works at the input of a transmitter...at the mic. Look for circuits used in cheap cassette recorders or rip one out. There might be an IC designed for just this. Sorry to state the obvious but I like to post now and then
Many years ago a JFET was used in an audio limiter circuit.
The audio was rectified and turned on the JFET that was used as an attenuator.
Signetics developed "compandor" ICs before Philips bought Signetics. Philips is called NXP nowadays.
There are (were?) 4 stereo compandor ICs. Each channel can be a compressor or an expander circuit.
Many years ago a JFET was used in an audio limiter circuit.
The audio was rectified and turned on the JFET that was used as an attenuator.
Signetics developed "compandor" ICs before Philips bought Signetics. Philips is called NXP nowadays.
There are (were?) 4 stereo compandor ICs. Each channel can be a compressor or an expander circuit.
Signetics invented the NE570 compander IC. Then Philips bought Signetics and Philips (now called NXP Semi) makes it. Motorola became ON Semi who also makes it.
Signetics invented the NE570 compander IC. Then Philips bought Signetics and Philips (now called NXP Semi) makes it. Motorola became ON Semi who also makes it.
Oh yeah, I remember Signetics. They used to make the DTMF chips.
I hooked up my P-P amp and yeah, it bumped up the drive, It's still pulling harder on one side. I'm getting about 10 watts of clean power but think I will get more if I can ballance it. I'm using 2N2222's and I droped the emitter resistors down for a second and blew both transistors. I think what happened was I touched the resistor across one RE first and it pulled real hard and blew then the other pulled everything and it blew. I dropped the REs back to 100 ohms but they still run kinda warm. I need some little heat sinks for them.
I posted it on other thread. Well it didn't have part values. It may be doing the job. I think it is. It looks like I'm getting feedback when I increase the power output. Wouldn't you know
Why did you copy the lousy P-P amplifier from the Philips 1955 handbook?
What is it for? A modulator?
Why two transformers?
Why any transformers instead of a pair of complementary emitter-followers like in an audio amplifier IC?
I think it causes a lot of distortion without the 100 ohm resistors but I cannot simulate it because it is too old.
Why did you copy the lousy P-P amplifier from the Philips 1955 handbook?
What is it for? A modulator?
Why two transformers?
Why any transformers instead of a pair of complementary emitter-followers like in an audio amplifier IC?
I think it causes a lot of distortion without the 100 ohm resistors but I cannot simulate it because it is too old.
When he said the P-P amplifier "bumped up the drive" I thought it is the transmitter's modulator.
A pair of little 2N2222 transistors do not produce much power.
When he said the P-P amplifier "bumped up the drive" I thought it is the transmitter's modulator.
A pair of little 2N2222 transistors do not produce much power.
Why did you copy the lousy P-P amplifier from the Philips 1955 handbook?
What is it for? A modulator?
Why two transformers?
Why any transformers instead of a pair of complementary emitter-followers like in an audio amplifier IC?
I think it causes a lot of distortion without the 100 ohm resistors but I cannot simulate it because it is too old.
I didn't copy anything. That's just a typical P-p Amp. I didn't think you would be able to check it. It's doing pretty good. I'm doing a finger check...lol. They are both are pretty warm. With big emitter resistors I don't think you need to be too concerned with matching the transistors.
No, well you got to figure. It's a home brew. So I wanted one big hairy ass filter on this board along with some drive. Since I'm putting the board in a cat food can, I only got room for one amplifier stage. So in order to get as much drive as possible, I went with a P-P amp.
I was not satisfied with the amount of carrier suppression. I really had to shout into the mic to see the carrier come through the crystal filter. Coming out of the balanced modulator the signal appeared to be pretty hefty but I suffered a great deal of attenuation through the filter. All of the sudden it hit me like a ton of bricks! The balanced modulator is a mixer which has been discussed. A POST MIXER AMP! I need a post mixer amp! I put it in and damn! It is great! Now I got to go back through my mixer and all that garbage because the carrier is really slamming now, but the modulation is way over that.