This was general.. lets be specific for each
frequency or say freq-range we have a particular
voltage assosiated so if you can make simple
transistor ckts that can trap up to a critical
voltage then you are through... With this i mean
that try to make simple transitor ckts that work
at a particular voltage say .1volt , .2volt and
so on as per the input range......this won't be
difficult and then you can attach the LEDs to
them to get the display....
Try and learn the basics rather than the Kits..
Actually, what you describe sounds like an LED bargraph circuit. The LM3914 and LM3915 (national semiconductor) chips are great for this. They will light up an LED for each step increase in voltage. Just like you describe. These are the chips that are always used for level indicators, or LED type VU meters in audio applications. It's certainly possible to make one from scratch out of transistors, but when you can do it with an off the shelf part, why not?
-Tavys
