Spectrum Analyzer Update
Posted by aonomus on August 4, 2008
Hi to all the folks from HackedGadgets, I have no idea why I got featured, but I suppose that’s enough to get me to stop being lazy and actually post an update. Here is the schematic for the most part, done in Eagle, but it throws a ton of ERC errors, so its not ready yet. I’m also waiting to try out some LM/NE5523/24 opamps to act as the preamp to the entire circuit since the LM358’s flat-out fail at giving a strong enough signal for the bandpass filters to work.
Below is the schematic, in rough form, at this point I’m mostly holding out to get the supplies to etch my own boards and figure out a decent preamp. Ontop of that I might replace the Vcc/2 stage (built from an opamp) with a separate regulator, I’m planning to power this thing from a 18V 1A brick power supply, so a 7809 would do just fine for a Vcc/2 without worrying about taking too much power, however for breadboarding purposes it seemed easier to make a Vcc/2 out of the unused opamp instead of an entire regulator.
Another excuse I have for not working on the spectrum analyzer was making a power supply out of an old UPS, I’ll get around to posting photos another day, right now though its 2am so this post may not be highly coherent.