Hey All,

I'm looking to receive an AM signal at, say, 100 kHz. I want to mix the received signal with a local oscillator to extract the AM signal. If this were a MHz-level carrier, I would just pick up a mixer, but I'm less sure of myself at these low of frequencies. I've looked into some parts, and what I find are mostly called "Multipliers," for example the AD633. Are these "multipliers," the mixers that I'm used to? Perhaps there is a better part for this task?

Thanks for your input!

 

Yes a mixer is a multiplier and a multiplier is a mixer. The AD633 should do what you want.

But mixing the 100kHz signal with a local oscillator will just give the sum and difference frequencies of those two, not necessarily the AM modulation. Or are you going to mix it with a 100kHz signal from the oscillator to extract the baseband modulation.

 

Excellent; Thanks.

Yes. The plan here is to extract the baseband modulation. After the mixer would come a lo-pass filter and then a buffer. The signal is AM modulated with a square wave at ~1Hz. I plan to use this baseband modulation to drive an LED and a buzzer.

Thanks again!

 

Hello,

It looks like you want to do a kind of "direct conversion" method, to demodulate a signal.

When you look at T1 in the schematic in the link, it performs the mixing process:
http://www.electronicsforu.com/efylinux/circuit/cir117.htm

Bertus

 

Wow. I'm glad I posted before building. I definitely don't even need a mixer, just some filters and a simple AM demodulator (ie: a diode). Sorry for bugging, but thank you for the replies. I'm sure this will come in handy some day!