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PA3BNX > TECH 13.12.05 14:06l 54 Lines 1626 Bytes #999 (0) @ EU
BID : 3460_PI8SHB
Read: GUEST DL1LCA DL7NDF OE7FMI
Subj: Sea Wave Generator.
Path: DB0FHN<DB0FOR<DB0SIF<DB0EA<DB0RES<ON0AR<PI8ZAA<PI8SHB
Sent: 051213/1054Z @:PI8SHB.#NBO.NLD.EU #:3460 ['s-Hertogenbosch] $:3460_PI8SHB
From: PA3BNX@PI8SHB.#NBO.NLD.EU
To : TECH@EU
Hello every body,
I recently made a pcb-hole project witch emulates the sound of the sea-waves.
Some sort of tranquilliser hi.
I found the circuit in Electuur 1-96 page 60.
I did build it and it works !
It are basicly 3 lf ocilators that modulate an e-b junction of a transistor
that generates noise witch is ampliflied by a normal audio ampliflier.
The current through the e-b junction is modulated.
It starts noise generating at about 5 volts across the e-b junction.
I watched the noise on the scope and saw that the noise is
not symmetrical but has bigger positive then negative amplitudes.
I tried other transistors but al the same result.
The e-b junction is base to earth and emittor to the current source plus.
So it is adjusted that the e-b junction is just zenering and generating
much noise.
The ocilators send more or less current so the noise amplitude varies
and it looks like the sound of the sea waves quite okay.
Basic parts tl084, 7812, bd139/140 and bc547b as noise and bc547 as audio pre-
amp.
So it is cheap to build.
It uses a smal speaker in a home made wooden yellow painted box with the
all electronics also in it..
Indeed such noises can relax your brain if you let it run some time hi.
It was nice to build again something with ordinairy cheap parts after spending
far to much time in programming my filecopy/scheduler and other programs.
So have fun and solder again something for not lossing your building skills hi.
Cheerio
73's from Lodewijk QTH Rhenen JO21SX.
5157.80N/00534.23E
PA3BNX@PI8SHB.#NBO.NLD.EU
IP nr. 44.137.40.41.
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