Sub Audio Frequency Doubler

Jacques St-Pierre · 2006-04-25T16:27:52+00:00

Hi,Do someone know a simple way to double a low frequency complex wave signal, real time, using an simple analog circuit?I need to rise the low frequency of a whale sound ( lower than 20hz) to an human audible level, around 40hz.ByeJacques

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Phil Allison 20 years ago

"Nico Coesel"

** The answer is an analogue pitch shifter that adds a fixed frequency ( say 30Hz) to the signal coming from the hydrophone. Whale noises previously in the *sub-sonic* range on will then appear in the easily audible range.

All other noises, from whales or *whatever*, that the hydrophone receives in the audible range from a few hundred Hertz up will be heard just as usual.

The other solutions do NOT offer the latter HUGE advantage.

Pitch shifting, time altering and modulation methods are all inappropriate for this app.

....... Phil

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Phil Allison 20 years ago

"Phil Allison"

Correction.

** The answer is an analogue frequency shifter....

....... Phil

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Jacques St-Pierre 20 years ago

Anyone as an schematics of a simple Analogue Frequency Shifter?

Jacques

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Tam/WB2TT 20 years ago

Run the signal and the offset frequency into a double balanced mixer, like an MC1496. Pass the output through a high pass filter to remove the lower sideband. Al;so, a low pass filter to eliminate harmonics. You might try something like 100 Hz offset.

Tam

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Phil Allison 20 years ago

"Jacques St-Pierre"

** See "Electronics Australia" magazine, August 1997

"Audio Frequency Shifter" by Phil Allison.

Covers the band from 20 Hz to 20 KHz with a 4.5 Hz up-shift.

Will require some component value changes for your app.

A PCB is available from:

formatting link

Code number: 97AFS8

....... Phil

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Phil Allison 20 years ago

"Tam/WB2TT"

** Utter madness.

Forget it.

.......... Phil

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Don Bowey 20 years ago

I disagree. It sound like a workable method.

Hold off on the crap and plainly tell us what about it is madness. That is, put up or shut up for a change.

Don

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Phil Allison 20 years ago

"Don Bowey"

** So says another pig ignorant f****it "ham" who has no clue what a "linear modulator" is.

......... Phil

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SioL 20 years ago

Elektor magazine, couple of years ago. Complete with PCB. Just change a couple caps in local oscillator (perhaps it was done with xtal, don't remember). It was made for eavesdropping of bats (ultrasound).

Siol ------------------------------------------------ Rather than a heartless beep Or a rude error message, See these simple words: "File not found."

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Phil Allison 20 years ago

"SioL" <

** Not even in the ball park.

....... Phil

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Jacques St-Pierre 20 years ago

Do you have a schematics somewhere I can look at?

Jacques

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Phil Allison 20 years ago

"Jacques St-Pierre"

** Yes - in my own files of course .

But would you be any better of if you saw them ??

....... Phil

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Don Bowey 20 years ago

Hey, Phil Bob,

Was this something you built to help you make funny noises on your CB.

10-4 or whatever!

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Jacques St-Pierre 20 years ago

Sorry, but I am not familliar with "Audio Frequency Shifting". I look to find any exemple without any luck. I found device to do that, or place to buy schematics, but nothing to let me know to to do it. Can you suggest any IC to do that? So I can get manufacturer sugested design exemple.

Bye Jacques

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Tam/WB2TT 20 years ago

I don't get your point. I have used the 1496 in such circuits, and they worked just fine. In fact I used one to generate an SSB signsl at 6 - 6.5 MHz using the phasing method. Maybe you want to design this guy a 90 degree phase shift network that will be flat from 5 Hz to 50 Hz.

Tam

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Don Bowey 20 years ago

Fred's point is at the top of his head.

He doesn't hang around to explain his opinion, because he doesn't know anything in enough detail. So he attempts to insult and runs.

His favorite, persistent thought is Duh?

Don

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Phil Allison 20 years ago

"Tam/WB2TT"

** Cos you are a thick as a brick ham.

** Irrelevant.

** I designed and published an "outphaser" covering from 20 Hz to 20 KHz within +/- 2 degrees - as part of the Audio Frequency Shifter project mentioned in another post.

It is a quite straight forward task.

.......... Phil

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Phil Allison 20 years ago

"Jacques St-Pierre"

** The info has been posted by me here - it is further down this page too.

Kindly answer my question.

Can YOU read and comprehend schematics ?

BTW 1

If you buy the PCB - simply ask and a copy of my article will be included.

Just how much spoon feeding do you need?

BTW 2

Do not f****ng TOP POST !!!!!!

......... Phil

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Nico Coesel 20 years ago

This sounds like a typical feed-back killer to me. Are you sure you can modify your circuit to convert 20 Hz to say 500 Hz?

Reply to nico@nctdevpuntnl (punt=.) Bedrijven en winkels vindt U op www.adresboekje.nl

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Phil Allison 20 years ago

"Nico Coesel"

** Yes - its purpose is an acoustic feedback stabiliser.

** Who needs to do any such damn silly thing ?

Are you a professional PITA f****it - Nico ??

Or just a keen amateur.

...... Phil

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Sub Audio Frequency Doubler

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