I have been thinking

[Staigen1]

Hi all of you

I have been thinking for a while, cant we(at least those of us that are active) go together and construct some instrumentation and other stuff, make them good, discuss them together, and upload them as projects here on this site?
For example you, Audioguru, have a good tone generator, i belive. And a funktion generator can be handy sometimes. A signalgenerator can be good for them that are into HF. A front end for a wideband oscilloscope connected to a computer can be handy. And so on, there are much moore, i belive.

//Staigen

 

[gogo2520]

    Staigen you are right
      I am new to electronics and find it easier to learn when I have something to study.  I could see some interest in a front end for wideband oscilloscope connected to a computer. Or maybe a frequency counter. Capacitor meter is another good one.
        Something to do and help people study.
                          good idea
                              thanks gogo

 

[audioguru2]

I have a fairly simple extremely low distortion tone generator circuit. I tried to make it sweepable with a 74HC4046 PLL but phase jitter ruined its low distortion. It has a fixed 400Hz frequency now. Its matching distortion analyser circuit is very stable, has the proper high Q and is pretty simple. They use the same HF master clock oscillator.
I used switched-capacitor Butterworth lowpass filter ICs from National that are discontinued now. It would need a re-design of its pcb to use Maxim ICs.

I re-made many times a Wien Bridge variable frequency oscillator but it suffers from squegging when the gain of its AGC loop is high.

I have a variable frequency phase-shift oscillator that works pretty well. It requires a 3-gang potentiometer that is nearly impossible to get. I robbed mine from the best-matched of four of them that were in a RadioShack parametric filter product.

I have a pink noise generator that uses National's discontinued IC. I tweaked its 3dB/octave filter to be very accurate.

 

[audioguru2]

Hi Zeppelin,
The power supply's improvements are still being added as more people build it.
Due to the wide tolerance of the control pots, people say the project's voltage goes too high, into rectifier ripple. They also say its current goes too high causing problems. We are thinking of adding trimpots in series with the control pots for calibration.