seeking parabolic mic circuit

[steven]

:)im looking fo a good simple parabolic microphone circuit , that will hear distant sounds really clear,with the microphone mounted in a dish . i want the type of circuit , that use a pair of headphones to listen with, i prefer the circuit, not be a transmitter type that tranmitts to an fm radio,

[ante]

Hi Steven,

I think here is a good one for you: http://www3.telus.net/chemelec/Projects/Parabolic-Mic/Parabolic-Mic.htm

[steven]

:)thanks ante ive seen that site the circuits are all in sections id like a circuit all in one more easyer to biuld from and workout. i did have one but it dident work the circuit was one from my old ex talking electronics book, and oneday i decided to biuld it but it dident work after all that time in putting it together, there was another circuit that really worked like a beauty but it was a transmitter type that transmitts sound it hears to an fm radio headset i used to have ,but tuneing it was difficult as it was like tuneing a short wave radio where the stations are so close that you can easily miss it and i got it better by pushing in the tuner rather than turning it. ill post it, see what you think

[steven]

[steven]

:)i cant find the microphone amplifier circuit i posted before, its somewhere in the forums but hear it is in biult form with the electret microphone allready in the spotlight dish i used and this time i rebiult the circuit and its working good but i want to increase the microphones sensitivity so any advice on doing that is welcome

[steven]

:)

[steven]

:)heres a close up of this circuit , the big ear circuit i posted else where is allso a parabolic microphone amplifier but its super sensitive and will hear faint and distant sounds really clear. but that circuit transmitts the sound to a nearby fm analoge radio

[audioguru]

Hi Steven,
In your LM386 circuit the electret microphone will be more sensitive if you change its supply/load resistor R1 to 10K.
The LM386 amp will be a lot more sensitive if you add a 10uF cap between its pins 1 and 8.

[steven]

:)audio guru ive allready added the 10uf electro between pins 1 and 8 incase you dident notice in the latest pictures, just slide the picture to the left and youll see, ive been checking out the microphone sections of other bug transmitters and some load resisters vary in values. anyhow thanks audio guru for your help, oh by the way ive been seeking simple head phone amp circuits and ive got a kit i once put together, i think its named after you audio guru its an audio amp, ill post the circuits soon as i go through my 2 boxes to find it , now do you reckon i could use it to amplify the headphone audio sounds from this parabolic mic circuit, ok i havent forgot what you said about useing a 1k resister across the output to eliminate the bangs

[steven]

audio guru, your a real genious, i changed the 2.2k load resister to a 10 k and it increased the sensitivity well, is that the maximin sensitivity i can get, if the sensitivity can be increased to maximin, then what load resister do you recamend i use. i may be able to switch in various resisters under your recamenadtions for selecting the sensitivity i may need