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isd 1000a

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New Member

I have been trying to get the isd 1000a voice/record circuit to work and I am having problems. This is my second time at trying this circuit and both times have had very little success :x. I can get the playback to work, at least I think it is--I hear a capacitor pulsing for about 20 seconds then the sound ends. The part I can't seem to get to work is the record. I have tried two different mics and still no luck.
This project is one from Radio Shack. I have followed the schematic as outlined. I have made other integrated circuits work. My experience is at the novice level.

Any ideas appreciated.
P.S. I believe the schematic from Radio Shack is incorrect.....


Active Member
Make sure of the polarity of the Condenser Mic. If used in reverse it won't work.

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