super sensitive microphone

We sure need more information on this question!

JERD

Most regular omnidirectional electret mic elements are very sensitive.

Used in their zillions in standard PC desk mics and headsets etc. Gain'em up as required.

Dave.

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A satellite(s) follows me everywhere making noise (voices) probably by heating the air at accoustic frequencies with a MASER.

For 7 years straight, verbally abusing me all day every day, and no its not in my head.

Herc aka The Truman

I had a FM bug that was more sensitive than the human ear, when someone was pouring a cup of tea I could hear it swirling and the pitch increasing. But the FM bug I just got from Talking Electronics was not very sensitive.

Can you buy something like a birdwatchers sound recorder?

Herc

All of the Talking Electronics bugs I built as a kid all had a standard electret microphone and could pickup anything "better than the ear" as you've found before. The new one you have obviously doesn't have enough gain, and/or has an insensitive mic. Perhaps it's designed for a different application? Can you change the gain on the front end amp? I'm sure Colin Mitchell at TE will be able to tell you what you need to know.

Dave.

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OK maybe its my radios. I tested it on a radio with a broken antenna and a MP3 player with a digital tuner, which went up in increments of 0.05 MHZ so it might have been out a bit. I'll get another radio to make sure it's not the bugs fault.

Herc

**Depends on what you are attempting to do. Usually, a good directional mic will provide what you want. There are a couple of variants on directional mics. You can construct something yourself, using a mixing bowl, with the microphone mounted at the centre. Similar to a satellite dish.

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Trevor Wilson
www.rageaudio.com.au

Maybe there's a maser beam converter program somewhere that will convert the beam into audio.

Rheilly P

**Huh?

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Trevor Wilson
www.rageaudio.com.au

Was just browsing from some old TE books yesterday :)

Some of the TE mics were designed more for handheld microphone use (ie not very sensitive) whereas others were designed to be very sensitive.

A very senstive mic overloaded when spoken into at close range and hence it needed to be throttled back.

Look for a resistor from the positive rail to the electret.

The lower the value the resistor (down to a few k ohm) the more sensitive the mic. Conversely a higher value mic resistor (say 47k) won't be that sensitive.

Experiment with lower values to make it more sensitive.

A tuning step of 0.05 MHz is fine for bugs (unless the bug's deviation is really really low).

The broken antenna will restrict the range but not the recovered audio.

Reception was really poor on both. Too late now I ordered a $15 radio from DSE. The frequency was 87.8 MHZ and the dial on the radio I ordered started at 88MHZ so should be close, I pulled the coil as wide as it will go to increase the frequency.

I asked Colin to mark on the bug what frequency it was, and he put 87-92!

Herc

"Rheilly Phoull" wrote >

It sounds like someone talking softly in the next room. Easy to hear everything they say, but the mike on my laptop can't pick it up.

The maser beam does make audio! You can hear half a dozen American agents talking all day. Given 1000s of people in Townsville have heard them, how would you explain a noise source that follows you everywhere?

Herc

Did you read the post ??

Increase the value of the microphone bias resistor to increase its sensitivity.

**Yep. I saw no mention of microwaves. The reason for the dish is to 'amplifiy' SOUND waves.

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Trevor Wilson
www.rageaudio.com.au

Lets assume for a moment there is a satellite that can punch a maser beam powerful enough to heat surface air enough to modulate audio.

You'd spot it's presence by the burnt spot on the ground caused by the microwave heating and by people exploding as their fluids turn to steam.

Still it would be awesome to throw your voice at right/wrong place, picture two teams of diplomats sitting tensely at the negotiating table as one party awaits the reply of the other and a voice suddenly says the wrong thing out of nowhere.

In actual fact I suspect you are hearing a certain Sydney toaster/ microwave oven repairman due to cold weather atmospheric ducting of microwaves under repair.

have to speak into.

Trying to record EVPs?

That's possible. You can buy directional speaker systems now. Woody Norris was one of the first people to develop practical ones that worked. Here is a demo (not that you can really hear the effect of course)

Dave.

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