• litewave

    From LU9DCE@21:5/101 to BBSRT on Sat Jun 29 07:40:04 2019
    AM LIGHTWAVE TRANSMITTER AND RECEIVER BY JOE SCHARF -------------------------------------------------------------------------------
    SCHEMATIC 1 [TRANSMITTER] -------------------------------------------------------------------------------


    MIC* C1
    () + .1 uF
    |---------(OO)-----|(--------| +9V
    | () | ^
    | R3 R4 | /|\
    | 5.6K 5.6K | |
    *---/\/\/\-------*---/\/\/\--|-------*-------*------|
    | | | | | |
    | | >R1 | | |
    | | |---->>>50K | >R5 >R8
    | __|3___|2_ >VAR | >1K >220
    | \ + - / |RESIST | > >
    | \OP AMP/-----|-------- | |
    *----------------\741 /7 | | | **
    | 4 \ / >R2 | C/NPN Q1
    | \/ >1M |---------B| TRANSISTOR
    | |6 > | | E\ 2N2222
    | | | C2 | | |
    | | | + 10 uF | >R6 |
    | ----------*---|(-----*-->>>50K |
    | >VAR |
    | |RESIST| LENS
    | | __|___*** ^
    | | \LED / (|)
    | | \ / ( | )
    | R7> \/ (|)
    | 1K> -----|---- \/
    | > | LENS
    | | | OPT.
    | | |
    | | |
    |--------------------------------------------*-------|
    |
    |
    --------
    ----
    -- _______________________________________________________________________________

    R1-GAIN CONTROL
    R6-LED BIAS CONTROL ADJUST R6 FOR BEST SOUND QUALITY
    R8-LIMITS CURRENT APPLIED TO LED

    * - MIC- USE CRYSTAL MICROPHONE OR ELECTRET UNIT (CONNECT RED LEAD TO 9V)
    ** - TRANSISTOR - USE A 2N2222 NPN TRANSISTOR.
    *** - LED - USE A HIGH-BRIGHTNESS RED OR HIGH POWERED INFRARED LED FOR BEST
    RESULTS _______________________________________________________________________________

    THE 741 AMPLIFIES VOICE SIGNALS FROM THE MICROPHONE AND COUPLES THEM THROUGH C2 TO MODULATOR TRANSISTOR Q1. FOR A FREE-SPACE RANGE OF UP TO 1000 FEET
    (AT NIGHT), USE A LENS TO COLLIMATE THE LED BEAM OR USE THIS CIRCUIT AS
    AN OPTICAL FIBER TRANSMITTER. _______________________________________________________________________________

    SCHEMATIC 2 --- AM LIGHTWAVE RECEIVER _______________________________________________________________________________

    |-----------------------------------------|
    | |
    | |
    | |
    | |
    >R1 |
    >100K |
    > |
    LENS | C1 .1uF |
    ^ *----|(---------*-------| |
    (|) C| | | |
    ( | ) /Q1 | | | +9V
    ( | ) B|PHOTOTRANSISTOR | | | ^
    (|) E\ |-----| | | | /|\
    \/ | | __|3_|2_ | | |
    LENS | | 4\ + - /7 | | |
    *-------*----\ 741/------|-----------------*---------*
    | \ / | | |
    | \/6 | | |
    | | >R2 | ------ C2
    | | >100K | ^^ .1 uF
    | | > | ^ |^
    | | | | |
    | |--------* | |
    | | | --------
    | | | ----
    | | 3|\ | -
    | | |------|+\|6
    | | | |* \--------------|
    | R3< | | /5 C3 | +
    | 10K<<------| |----|-/| 100uF -----
    | VAR< | 2|/4| ^
    | RESIST| | | |
    | | | | 8 OHM|---/|
    | | | | SPEAKER| ||
    | | | | |---\|
    | | | | |
    |------------------------*---------*-------*--------------|
    |
    |
    ----------
    ------
    -- _______________________________________________________________________________

    R2-GAIN CONTROL
    R3-VOLUME CONTROL
    C2-PREVENTS OSCILLATION KEEP LEADS TO BATTERY SHORT.

    * --- OP AMP --- THIS MAY NOT LOOK LIKE AN OP-AMP BUT IT IS (VERY HARD TO
    DRAW THEM ON THE COMPUTER. USE A 386 OP AMP FOR THIS ONE _______________________________________________________________________________

    THIS RECEIVER WORKS BEST IN SUBDUED LIGHT OR AT NIGHT WHEN USED FOR
    FREE-SPACE COMMUNICATIONS ALWAYS PLACE A SHIELD OVER THE DETECTOR IF SUNLIGHT OR BRIGHT ARTIFICIAL LIGHT IS PRESENT. AN INFRARED FILTER SHOULD BE USED
    FOR BEST RESULTS (DEVELOPED COLOR FILM WORKS WELL) UNLESS THE TRANSMITER
    LED EMITS VISIBLE LIGHT.

    CAUTION : THIS CIRCUIT CAN PRODUCE LOUD SOUNDS. DO NOT PLACE SPEAKER CLOSE
    TO YOUR EAR. _______________________________________________________________________________

    FEEL FREE TO PASS THIS CIRCUIT AROUND AND IF YOU HAVE ANY QUESTIONS OR
    PROBLEMS YOU CAN CONTACT ME ON CHUCKS PLACE (304)-776-7078 BY LEAVING E-MAIL TO: JOE SCHARF _______________________________________________________________________________


    --- Mystic BBS v1.12 A43 (Linux/32)
    * Origin: HAMRADIO telnet lu9dce.dynu.com (21:5/101)