mvs sarma
Well-Known Member
In fact, I was thinking about the 1st transistor's collector activity that needs the filtering. It is conventional to have a series drop resistor and a decoupling for powering the Electret MIC.Most electret mics operate at 0.5mA then a 10k resistor from 9V is perfect.
I agree that the 10k resistor that feeds the mic should be decoupled from the 9V with a 1k resistor is series from 9V then a 47uF capacitor to ground. Then there will be no motorboating.
I see many kits in market with minimal components. The LC meter of electronicvs-diy is one such.It has no electrolytics at all on the power line even aftewr having 78x05 regulator.
with due regards to Colin, It is OK if one sells 100,000 kits. One could save that much on investment.