AM Modulation

You're playing with words. Amplitude modulation is multiplication, and whether you consider multiplication to be "linear" is up to you.

John

I can simulate it well enough in my head. Your circuit is not a multiplier so it does not create the sidebands required of an Amplitude Modulation process.

Your circuit is a mixer in the sense of an audio mixer. Yes you are "modulating) a summation point in the circuit, but that is very different from "AM,"

Let's make a couple minimal changes to obtain an Amplitude Modulation circuit, the output of which will contain the products and also the unfiltered inputs:

Variable Modulation signal (f2) input (referenced to gnd)

Linear Modulation is merely a term to denote that, in the case of AM, the modulation product(s) contain one or more sidebands, each of which has the same bandwidth and shape as the modulating signal (voice, tone, whatever).

The process of doing that is necessarily, non-linear.

Don

We keep going over and over this ground, about whether you need nonlinearity to get sidebands. It tends to be, as in this case, people who half-remember stuff from lectures vs other people, some of whom know nothing and some of whom can actually still do algebra. (You know who you are.)

We talked about this in September, and actually generated some insight:

Cheers,

Phil Hobbs

It's an herb, kind of like parsley or oregano, but it tastes kinda like laundry soap.

Cheers! Rich

You guys just have no taste... Cilantro is good stuff.

But then, I'm the kind of guy who like fennel ;-)

...Jim Thompson

It's great stuff, when fresh, IMHO. My recipe for Jinga (shrimp) Dhania (cilantro) Masala has a cup of fresh coriander/cilantro in it, along with cumin, fennel and green chilies. The sauce is bright green.

Or sometimes "Chinese Parsley".

Best regards, Spehro Pefhany

Nobody eats parsley.

John

The LDR divider does change the amplitide of the carrier GEN2, in response to another signal, GEN1. So it's a modulator, and it does create sidebands. Heck, it generates *more* sidebands than any self-respecting AM modulator should.

John

Saw an interesting study about a year back which showed that the average length of a marriage these days is a gnat's whisker over 20 years, the same as it was several decades ago, and several hundred years before that. The changing part of the equation is lifespan.

Cheers.

Ken

Like I said - cucumber!! :-)

Cheers.

Ken

Aha. That grows in small bottles in supermarkets doesn't it?

Cheers.

Ken

Divorce is so easy these days, and no one seems to take the trouble to make sure they've chosen a partner correctly.

Ours is one of those teenage marriages that was supposed to fail... in fact my mother-in-law was fond of saying, "Wait one more day, until April Fool's Day" ;-)

March 31 will mark our 46th year!

...Jim Thompson

--- We like it (cilantro) in beef fajita tacos, sometimes. Beef fajitas are flank steak that's been marinated and grilled after the membrane's been removed. To make a beef fajita taco, you get some beef fajitas that've been sitting on the grill for a while and are ready, and you roll a flour tortilla around them. Some folks like to add guacamole, or maybe pico de gallo, or maybe chile con queso to the fajitas, once they're on the tortilla, and then roll it up and eat it.

I like to add chile con queso, and to have a nice, cold Negra Modelo on the side to wash it down with.

BTW, "fajita" is pronounced like 'fa' in do,re,mi,fa, 'he' like the opposite of 'she', and 'ta' like the 'ta' in 'tardy'

--- Larkin beat me to it...

---

--- Now my day is complete!

Reminds me of...

Did you hear about the woman who ate a doorknob? It turned her stomach.

-- John Fields Professional Circuit Designer