Part 1: Three-Band Tone Control

Digging through datasheets will always, ALWAYS give you great ideas. Looking in the datasheet for the TL082 dual JFET opamp (oddly available even at my podunk radioshack) found me this little gem.

Tone Control Schematic

Three Band Tone Control Schematic

Nice and simple, eh? Awesome, I know right? But for what use? Obviously for audio, but modern audio doesn’t require this, unless your building amplifiers…or radio transmitters…more after the break…

In case you’re not familiar with the Pixie (or Pixie II, moreso), it’s a high frequency (ham band) morse code transceiver that can fit into an Altoids tin. It is absolutely unbelieveably awesome, go build one now.* Anyway, it’s not a $4000 transmitter, so understandably, its not the strongest transmitter or receiver. So, I’m going to do everything I can to improve it because I’m damn sure not going to pay more when I could hack more. GahahaHAHA!

*Get your Ham License First! This is all you need. It’s easy and cheap. All thanks to Dan Romanchik, KB6NU, over at his blog for making this possible.

Back on topic, the pixie is a morse code transmitter, so it requires a few modifications** to use for voice. And beyond that, I want to be able to switch bands, use multiple antennae, and of course, transmit data worldwide.

**The problem with simply making the modifications described in this link, is it is unavailable to basic (technician) licensees. And also likely illegal in the US.

And on that bombshell, here’s something relevant to an upcoming post. Fourth-order Butterworth Filters! Good night everybody.


Fourth Order!

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