=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
5
 $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
 $       Box Plans..                 $
 $                                   $
 $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$   THIS FILE WILL EXPLAIN THE        $
$ CONSTRUCTION, TROUBLESHOOTING, AND  $
$ ADJUSTMENT OF A BLUE BOX.           $
$                                     $
$                                     $
$                                     $
$   WE ALL KNOW THAT THE TOUCH TONE   $
$ FREQUENCIES ARE COMPOSED OF 2 TONES $
$ (2 DIFFERENT FREQS.) SO THAT IS THE $
$ REASON WHY WE HAVE 2 VCO'S (VOLTAGE $
$ CONTROLLED OSCILATORS). WE'LL CALL  $
$ THEM VCO#1 AND VCO#2. IF YOU HAVE   $
$ NOTICED VCO#1 AND VCO#2 ARE EXACTLY $
$ THE SAME TYPE OF CIRCUITS. THAT IS  $
$ WHY ONLY 1 WAS DRAWN. BUT REMEMBER  $
$ THAT WHATEVER GOES FOR VCO#1 ALSO   $
$ GOES FOR VCO#2. BOTH VCO'S ARE      $
$ COMPOSED OF A HANDFULL OF PART. ONE $
$ CHIP, TWO CAPACITORS, 2 RESISTORS   $
$ AND FIVE POTENTIOMETERS. ALL OF     $
$ THIS WILL GIVE YOU (WN PROPERLY   $
$ CALIBRATED) ONE OF THE FREQENCIES   $
$ NECESSARY (THE OTHER ONE WILL COME  $
$ FROM VCO#2) FOR THE OPERATION OF    $
$ THE BLUE BOX. BOTH OF THESE FREQS.  $
$ WILL BE MIXED IN THE SPEAKER TO     $
$ FORM THE REQUIRED TONE.             $
$                                     $
$                                     $
$   THIS IS ONE OF THE MOST           $
$ SOPHISTICATED DESIGNS I HAVE EVER   $
$ MADE. WHY?. BECAUSE OTHER DESIGNS   $
$ WILL DRAIN THE BATTERY AFTER 10     $
$ CALLS. THIS DESIGN WILL MAKE THEM   $
$ LAST 10 MONTHS!!!!!!. BUT NEVER THE $
$ LESS, DON'T FORGET TO PUT IN A      $
$ SWITCH FOR ON AND OFF. OK LET'S     $
$ BUILD THE TWO VCO'S AND CALIBRATE   $
$ THE UNIT BEFORE WE GET TO THE       $
$ KEYBOARD CONSTRUCTION.              $
$                                     $
<                                     >
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
                                     !
          VCO CONSTRUCTION           !
          === ============           !
                                     !
           TOOLS REQUIRED            !
           ----- --------            !
                                     !
 1 OCILLISCOPE(OPTIONAL BUT NOT REQ) !
 1 FREQ. COUNTER   (REQUIRED)        !
 1 VOLT METER       "  "  "          !
   ELECTRONICS TOOLS  (PLIERS,DRLL,  !
   SCREWDRIVERS, ETC.)               !
                                     !
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
<                                     >
.......................................
.                                     .
.           -------------             .
.           ! $-PARTS-$ !             .
.           -------------             .
.                                     .
. R1  1.5K RESISTOR  5%               .
. R2  1K   RESISTOR  5%               .
. C1 .1UF ELECTROLYTIC CAPACITOR 16VDC.
. C2 .01UF    "        "  (MYLQR)16VDC.
.IC1 2207 VCO CHIP BY EXAR ELECTRONICS.
.    REMEMBER THE ABOVE ONLY SAYS     .
.    VCO#1 BUT THE SAME IS FOR VCO#2  .
. R3-R4 150 OHM RESISTORS  5%         .
. C3-C4 .1 UF ELECTROLITIC CAPACITOR  .
.       10VDC                         .
. P1-P10 200K TRIMMER POT - 20 TURNS  .
.       DIODES USED IN THE KEYBOARD   .
.       ARE 1N914 TYPE (40 OF THEM) & .
.       13 SWITCHES FOR THE KEYBOARD  .
.       SPST MOMENTARY.               .
. SPKR=YOU CAN USE A TELEPHONE SPEAKER.
.      FOR THIS (IT WORKS BEST) BUT   .
.      REMEMBER TO TAKE OUT THE DIODE .
.      THAT IS CONNECTED ACCROSS IT.  .
.                                     .
.......................................
<                                     >
***************************************
*                                     *
*        ---------------------        *
*        ! *IMPORTANT NOTES* !        *
*        ---------------------        *
*                                     *
*  1. DO NOT USE ANYTHING ELSE OTHER  *
*     THAN A MYLAR CAPACITOR FOR C2.  *
*  2. PINS 10,9,8 SHOULD BE TIED      *
*     TOGETHER AND BE LEFT FLOATING.  *
*  3. ALL RESISTORS SHOULD BE 5%!     *
*     NOTHING ELSE!                   *
*  4. A TELEPHONE SPEAKER GIVES THE   *
*     BEST RESULTS.                   *
*                                     *
***************************************
<                                     >
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                     %
%         --------------------        %
%         ! TROUBLE SHOOTING !        %
%         --------------------        %
%                                     %
%   BY NOW YOU SHOULD HAVE CONSTRUCTED%
% THE TWO VCO'S ON A BREAD BOARD OR   %
% ANYTHING THAT PLEASES YOU.          %
% CHECK FOR COLD SOLDER JOINTS, BROKEN%
% WIRES, POLARITY OF THE BATTERY, ETC.%
% BEFORE WE APPLY POWER TO THE VCO'S  %
% WE HAVE TO ADJUST THE POTS FOR THEIR%
% HALF WAY TRAVEL POINT. THIS IS DONE %
% BY TURNING THEM 21 TURNS TO THE     %
% RIGHT AND THEN 10 TURNS TO THE LEFT.%
% DO THE SAME FOR ALL TEN OF THEM.    %
%                                     %
%-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-%
%                                     %
%   NOW APPLY POWER TO THE UNIT CHECK %
%  TO SEE THATY YOU HAVE POWER IN THE %
% CHIPS BY PUTTING THE POSITIVE LEAD  %
% OF YOUR VOLT METER ON PIN 7 AND THE %
% NEGATIVE LEAD ON PIN 12. IF YOU DO  %
% NOT HAVE ANYTHING THERE TURN OFF    %
% THE UNIT AND RECHECK THE WIRING.    %
%                                     %
%-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-%
%                                     %
%   WHEN YOU GET THE RIGHT VOLTAGES   %
% ON THE CHIPS, CONNECT A DIODE TO A  %
% PIECE OF WIRE (LOOK AT FIG. 2 FOR   %
% THE ORIENTATION OF THE DIODE) FROM  %
% GROUND TO ANY POT AT POINT T (LOOK  %
% CAREFULLY AT THE SCHEMATIC FOR      %
% POINT T IT IS LABELED T1-T10 FOR    %
% ALL POTS). YOU SHOULD BE ABLE TO    %
% HEAR A TONE, IF NOT DISCONNECT THE  %
% LEAD AND PLACE THE SPEAKER CLOSE TO %
% YOUR EAR AND IF YOU HEAR A          %
% CHIRP-LIKE SOUND, THIS MEA^S THAT   %
% THE TWO VCO'S ARE WORKING IF YOU    %
% DON'T, IT MEANS THAT EITHER ONE OR  %
% BOTH OF THE VCO'S ARE DEAD. SO IN   %
% THIS CASE IT IS ALWAYS GOOD TO HAVE %
% AN OCILLOSCOPE ON HAND.             %
% DISCONNECT THE SPEAKER FROM THE     %
% CIRCUIT AND HOOK THE OCILLISCOPE TO %
% 1 OF THE LEADS OF THE SPEAKER & THE %
% GROUND FROM THE SCOPE TO THE GROUND %
% OF THE BATTERY. CONNECT AGAIN THE   %
% GROUND LEAD WITH THE DIODE CONNECTED%
% TO IT FROM GROUND TO ANY POT ON THE %
% VCO THAT YOU ARE CHECKING AND YOU   %
% SHOULD SEE A TRIANGLE WAVE IF NOT   %
% TURN THE POT IN WHICH YOU ARE       %
% APPLYING THE GROUND TO UNTIL YOU SEE%
% IT. WHEN YOU DO SEE IT DO THE THE   %
% SAME FOR THE OTHER VCO TO MAKE SURE %
% IT IS WORKING. (AMPLITUDE IS ABOUT  %
% 2VAC). WHEN YOU GET THE TWO VCO'S   %
% WORKING YOU ARE SET FOR THE         %
% ADJUSTMENT OF THE INDIVIDUALS POTS. %
%                                     %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
<                                     >
:::::::::::::::::::::::::::::::::::::::
:                                     :
:            --------------           :
:            ! ADJUSTMENT !           :
:            --------------           :
:                                     :
:   DISCONNECT THE SPEAKER FROM THE   :
: CIRCUIT AND CONNECT A FREQ. COUNTER :
: (THE POSITIVE LEAD OF THE COUNTER TO:
: ONE OF THE SPEAKERS LEADS THAT      :
: BELONGS TO VCO#1 OR CONNECT IT TO   :
: PIN 14).                            :
:                                     :
:-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-:
:                                     :
:   CONNECT THE NEGATIVE LEAD TO THE  :
: BATTERY NEGATIVE AND CONNECT THE    :
: JUMPER LEAD WITH THE DIODE FROM     :
: GROUND TO POT NUMBER 1.T1.          :
: ( THE FIRST POT NUMBER 1 POINT T1)  :
: IF YOU GOT IT WORKING YOU SHOULD    :
: HEAR A TONE AND GET A READING ON    :
: THE COUNTER. ADJUST THE POT FOR A   :
: FREQ. OF 1700HZ AND CONTINUE DOING  :
: THE SAME FOR POTS 2-5 EXCEPT THAT   :
: THEY GET DIFFERENTS FREQS. WHICH ARE:
:                                     :
:            $            $           :
:            $ P1= 1700HZ $           :
:            $ P2= 1300HZ $           :
:            $ P3= 1100HZ $           :
:            $ P4=  900HZ $           :
:            $ P5= 1500HZ $           :
:            $            $           :
:                                     :
:   NOW DISCONNECT THE FREQ. COUNTER  :
: FROM THE SPEAKER LEAD OF VCO#1 OR   :
: FROM PIN 14 (WHICH EVER YOU HAD IT  :
: ATTACHED TO AT THE BEGINNING) AND   :
: CONNECT IT TO THE SPEAKER LEAD OF   :
: VCO#2 OR TO PIN 14 OF VCO#2 AND     :
: MAKE THE SAME ADJUSTMENTS TO P6-10. :
:                                     :
:            $             $          :
:            $ P6=  1100HZ $          :
:            $ P7=   700HZ $          :
:            $ P8=   900HZ $          :
:            $ P9=  2600HZ $          :
:            $ P10= 1500HZ $          :
:            $             $          :
:                                     :
:   WHEN YOU FINISH DOING ALL OF THE  :
: POTS GO BACK AND RE-CHECK THEM.     :
:                                     :
:::::::::::::::::::::::::::::::::::::::
<                                     >
<!><!><!><!><!><!><!><!><!><!><!><!><!>
<                                     >
<             ------------            >
<             ! KEYBOARD !            >
<             ------------            >
<                                     >
<   IF YOU LOOK AT FIG-2 YOU WILL SEE >
< THAT THE KEYS ARE SIMPLE SWITCHES.  >
< CONNECTED TO A GROUND AND TWO       >
< DIODES ON THE OTHER END. THESE      >
< DIODES ARE USED TO SIMPLIFY THE     >
< CONSTRUCTION OF THE KEYBOARD        >
< BECAUSE OTHERWISE THE DISTRIBUTION  >
< OF THE GROUND SIGNAL FOR BOTH VCO'S >
< WOULD HAVE BEEN DONE MECHANICALLY.  >
< THE DIODE WILL GO TO VCO#1 AND THE  >
< OTHER WILL GO TO VCO#2. FIG-3 SHOWS >
< THE ARRANGEMENT OF THE KEYS ON THE  >
< KEYBOARD.                           >
<                                     >
<-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=->
<                                     >
<   BELOW IS A TABLE THAT WILL HELP   >
< YOU CONNECT THE KEYS TO THE         >
< REQUIRED VCO'S POTS.                >
<                                     >
<-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=->
<                                     >
<              (-FIG 2-)              >
<                                     >
<-----!-----!--------!--------!------->
<     !     !        !        !       >
< TO  ! TO  !  FREQ  !  FREQ  !  KEY  >
< POT ! POT !  OUT:  !  OUT:  !       >
< ON  ! ON  !        !        !       >
< VCO1! VCO2!        !        !       >
<-----!-----!--------!--------!------->
<  1  !  06 ! 1700HZ ! 1100HZ !   C   >
<  2  !  10 ! 1300HZ ! 1500HZ !   0   >
<  1  !  10 ! 1700HZ ! 1100HZ !   E   >
<  4  !  07 ! 0900HZ ! 0700HZ !   1   >
<  3  !  07 ! 1100HZ ! 0700HZ !   2   >
<  3  !  08 ! 1100HZ ! 0900HZ !   3   >
<  2  !  07 ! 1300HZ ! 0700HZ !   4   >
<  2  !  08 ! 1300HZ ! 0900HZ !   5   >
<  2  !  06 ! 1300HZ ! 1100HZ !   6   >
<  5  !  07 ! 1500HZ ! 0700HZ !   7   >
<  5  !  08 ! 1500HZ ! 0900HZ !   8   >
<  5  !  06 ! 1500HZ ! 1100HZ !   9   >
<  -  !  09 ! ------ ! 2600HZ !   X   >
<     !     !        !        !       >
<-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=->
<                                     >
<   REMEMBER THAT IN FIG-2 IT'S THE   >
< SAME FOR EACH KEY EXCEPT THE "X"    >
< KEY, WHICH ONLY TAKES ONE DIODE.    >
<                                     >
<!><!><!><!><!><!><!><!><!><!><!><!><!>
<                                     >
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+                                     +
+   AS A FINAL WORD YOU CAN BUILD     +
+ THIS IN ANY TYPE OF ENCLOSURE AND   +
+ SHOULD NEVER BE USED TO MAKE FREE   +
+ CALLS USING THE TELEPHONE LINES, OR +
+ ANYTHING ELSE ILLEGAL.              +
+                                     +
+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+
[5] Tfiles: (1-23,?,Q) : 
G-file from.. MATRIX  [908-905-6691] -*-
 ---===<*>  Building Of A Blue Box !  <*>===---
 WE ALL KNOW THAT THE TOUCH TONES FREQUENCIES ARE COMPOSED
OF TWO TONES (TWO DIFFERENT FREQS.) SO THAT IS THE REASON
WHY WE HAVE 2 VCO'S ( VOLTAGE CONTROLLED OSCILLATORS). WE
WILL CALL THESE VCO#1 AND VCO#2. IF YOU HAVE NOTICED
VCO#1 AND VCO#2 ARE EXACTLY THE SAME TYPE OF CIRCUITS.
THAT IS WHY ONLY ONE WAS DRAWN. BUT REMEMBER THAT WHATEVER
GOES FOR VCO#1 ALSO GOES FOR VCO#2. BOTH VCO'S ARE COMPOSED
OF A HANDFULL OF PARTS. ONE CHIP TWO CAPACITORS 2 RESISTORS
AND FIVE POTENTIOMETERS. ALL OF THIS WILL GIVE YOU (WHEN PROPERLY
CALIBRATED) ONE OF THE FREQS. NECESSARY (THE OTHER ONE WILL
COME FROM VCO#2) FOR THE OPERATION OF THE BB. BOTH OF THESE
FREQS. WILL BE MIXED IN THE SPEAKER THUS FORMING THE REQUIRED
TONE.
 
THIS IS ONE OF THE MOST SOPHISTICATED DESIGNS I HAVE EVER MADE.
WHY?. BECAUSE OTHER DESIGNS WILL DRAIN THE BATTERY AFTER 10 -
CALLS! THIS DESIGN WILL MAKE THEM LAST 10 MONTHS!!!!!!. BUT
NEVERTHELESS DON'T FORGET TO PUT IN A SWITCH FOR ON AND OFF.
 OK LET'S BUILD THE TWO VCO'S AND CALIBRATE THE UNIT BEFORE
WE GET TO THE KEYBOARD CONTRUCTION.
 
 
                       VCO CONTRUCTION
                       === ===========
  TOOLS REQUIRED
 
 1 OSCILLOSCOPE    (RECOMMENDED BUT NOT REQUIRED)
 1 FREQ. COUNTER   (REQUIRED)
 1 VOLT METER       "  "  "
  ELECTRONICS TOOLS  (PLIERS, DRILL, SCREWDRIVERS, ETC)
 
 
      PARTS
 
 R1    1.5K RESISTOR  5%
 R2    1K   RESISTOR  5%
 C1    .1UF ELECTROLYTIC CAPACITOR   16VDC
 C2    .01UF ELECTROLYTIC CAPACITOR (MYLAR) 16VDC
 IC1   2207  VCO CHIP  BY EXAR ELECTRINICS
 REMEMBER THE ABOVE IT IS ONLY FOR VCO#1 BUT THE SAME GOES FOR
 VCO#2.
 
  R3-R4  150 OHM RESISTORS  5%
  C3-C4   .1 UF  ELECTROLITIC CAPACITOR   10VDC
  P1-P10 200K TRIMMER POT - 20 TURNS
  DIODES USED IN THE KEYBOARD ARE 1N914 TYPE (40 OF THEM)
  AND 13 SWITCHES FOR THE KEYBOARD SPST. MOMENTARY.
 
  SPKR= YOU CAN USE A TELEPHONE SPEAKER FOR THIS(IT WORKS BEST)
        BUT REMEMBER TO TAKE OUT THE DIODE THAT IS CONNECTED
        ACCROSS IT.
****************************************************************
                 IMPORTANT NOTES
 
   1 DO NOT USE ANYTHING ELSE THAN A MYLAR CAPACITOR FOR C2
   2 PINS 10,9,8 SHOULD BE TIED TOGETHER AND BE LEFT  FLOATING.
   3 ALL RESISTOR SHOULD BE 5%! NOTHING ELSE
   4 A TELEPHONE SPEAKER GIVES THE BEST RESULTS
*****************************************************************
 
 
                TROUBLE SHOOTING
 
 BY NOW YOU SHOULD HAVE CONSTRUCTED THE TWO VCO'S
ON A BREAD BOARD OR ANYTHING THAT PLEASES YOU.
 
 CHECK FOR COLD SOLDER JOINTS, BROKEN WIRES, POLARITY
OF THE BATTERY, ETC.........
 
 BEFORE WE APPLY POWER TO THE VCO'S WE HAVE TO ADJUST THE POTS
FOR THEIR HALF WAY TRAVEL POINT. THIS IS DONE BY TURNING THEM
21 TURNS TO THE RIGHT AND THEN 10 TURNS TO THE LEFT. DO THE
SAME FOR ALL TEN OF THEM.
 
NOW APPLY POWER TO THE UNIT CHECK TO SEE THAT YOU HAVE POWER
IN THE CHIPS BY PUTTING THE POSITIVE LEAD OF YOUR VOLT METER
ON PIN 7 AND THE NEGATIVE LEAD ON PIN 12. IF YOU DON'T HAVE
ANYTHING THERE TURN OFF THE UNIT ANT RECHECK THE WIRING.
 
WHEN YOU GET THE RIGHT VOLTAGES ON THE CHIPS, CONNECT A
DIODE TO A PIECE OF WIRE (LOOK AT FIG. 2 FOR THE ORIENTATION
OF THE DIODE) FROM GROUND TO ANY POT AT POINT T (LOOK CAREFULLY
AT THE SCHEMATIC FOR POINT T IT IS LABELED T1-T10 FOR ALL POTS)
 YOU SHOLD BE ABLE TO HEAR A TONE, IF NOT DISSCONNECT THE LEAD
AND PLACE THE SPEAKER CLOSE TO YOUR EAR AND IF YOU HEAR A CHIRP
LIKE SOUND, THIS MEANS THAT THE TWO VCO'S ARE WORKING IF YOU DON'T,
IT MEANS THAT EITHER ONE OR BOTH OF THE VCO'S IS DEAD.
SO IN THIS CASE IT IS ALLWAYS GOOD TO HAVE AN OSCILLOSCOPE ON HAND.
 
 DISCONNECT THE SPEAKER FROM THE CIRCUIT AND HOOKUP THE OCILLISCOPE
TO ONE OF THE LEADS OF THE SPEAKER AND THE GROUND FROM THE SCOPE
TO THE GROUND OF THE BATTERY. CONNECT AGAIN THE GROUND LEAD
WITH THE DIODE CONNECTED TO IT FROM GROUND TO ANY POT ON THE
VCO THAT YOU ARE CHECKING AND YOU SHOULD SEE A TRIANGLE WAVE
IF NOT TURN THE POT IN WICH YOU ARE APPLYING THE GROUND TO
QUNTIL YOU SEE IT. WHEN YOU DO SEE IT DO THE THE SAME FOR THE
OTHER VCO TO MAKE SURE IT IS WORKING. (AMPLITUDE IS ABOUT 2VAC)
WHEN YOU GET THE TWO VCO'S WORKING YOU ARE SET FOR THE ADJUSTMENT
OF THE INDIVIDUALS POTS...
 
                       ADJUSTMENT
 
 
   DISCONNECT THE SPEAKER FROM THE CIRCUIT AND CONNECT A FREQ.
COUNTER (THE POSITIVE LEAD OF THE COUNTER TO ONE OF THE SPEAKERS
LEADS THAT BELONGS TO VCO#1 OR CONNECT IT TO PIN 14).
 
   CONNECT THE NEGATIVE LEAD TO THE BATTERY NEGATIVE AND
CONNECT THE JUMPER LEAD WITH THE DIODE FROM GROUND TO POT NUMBER 1
T1 .( THE FIRST POT NUMBER 1 POINT T1)
 IF YOU GOT IT WORKING YOU SHOULD HEAR A TONE AND GET A READING ON THE
COUNTER.  ADJUST THE POT FOR A FREQ. OF 1700HZ AND CONTINUE DOING THE
SAME FOR POTS 2-5 EXCEPT THAT THEY GET DIFFERENTS FREQS.
 
 
                    P1= 1700HZ
                    P2= 1300HZ
                    P3= 1100HZ
                    P4=  900HZ
                    P5= 1500HZ
 
 NOW DISCONNECT THE FREQ. COUNTER FROM THE SPEAKER LEAD OF VCO#1 OR
FROM PIN 14 (WHICH EVER YOU HAD IT ATTACHED TO AT THE BEGINNING) AND
CONNECT IT TO THE SPEAKER LEAD OF VCO#2 OR TO PIN 14 OF VCO#2 AND
PERFORM THE SAME ADJUSTMENTS TO P6-10.
 
                    P6= 1100HZ
                    P7=  700HZ
                    P8=  900HZ
                    P9=  2600HZ   MAGIC NUMBER!!!!!
                    P10= 1500HZ
 
  WHEN YOU FINISH DOING ALL OF THE POT GO BACK AND RECHECK THEM
AGAIN.
 
 
                 KEYBOARD
 IF YOU LOOK AT FIG-2 YOU WILL SEE THAT THE KEYS ARE SIMPLE SWITCHES
CONNECTED TO GROUND AND TWO DIODES ON THE OTHER END. THESE DIODES
ARE USED TO SIMPLIFY THE CONSTRUCTION OF THE KEYBOARD BECAUSE OTHERWISE
THE DISTRIBUTION OF THE GROUND SIGNAL FOR BOTH VCO'S WOULD HAVE BEEN
DONE MECHANICALLY.  ONE DIODE WILL GO TO VCO#1 AND THE OTHER WILL GO TO
VCO#2. FIG-3 SHOWS THE ARRANGEMENT OF THE KEYS ON THE KEYBOARD.
 
 
          DBELOW IS A TABLE THAT WILL HELP YOU CONNECT
 THE KEYS TO REQUIRED VCO'S POTS.
 
                TO               TO             FREQ OUT            FREQ OUT
     KEY     POT ON VCO1     POT ON VCO2        PIN 14 VCO1       PIN 14 VCO
      C          1                6              1700              1100
      0          2                10             1300              1500
      E          1                10             1700              1500
      1          4                7               900               700
      2          3                7              1100               700
      3          3                8              1100               900
      4          2                7              1300               700
      5          2                8              1300               900
      6          2                6              1300              1100
      7          5                7              1500               700
      8          5                8              1500               900
      9          5                6              1500              1100
      X          -                9              ----              2600
 
***********************************************************************
* REMEMBER THAT FIG-2 IT IS THE SAME FOR EACH KEY EXCEPT THE "X" WHICH*
* ONLY TAKES ONE DIODE.                                               *
***********************************************************************
 
 
  AS A FINAL WORD YOU CAN BUILD THIS IN ANY TYPE OF ENCLOSURE
AND SHOULD NEVER BE USED TO MAKE FREE CALLS USING THE TELEPHONE
LINES. I HOPE THIS BULLETIN WILL CLEAR ANY QUESTION YOU MAY
HAD ON THE BLUE BOXES.
                               KEY
                               ===
 
 
 FIRST A FEW KEYS TO THE DIAGRAM:
 
 CX IS CAPACITOR #X   DENOTED BY: ---] ]---
 
 
 PX IS POT OR VARIABLE RESISTOR #X  DENOTED BY :/
                                                \
                                                /<--
                                                \
 RX IS RESISTOR #X  DENOTED BY /\/\/\/\
 
 
                             SCHEMATICS
                             ==========
 
      THE XR-2207 CHIP IS A VOLTAGE-CONTROLLED OSCILLATOR AND A 14
 PIN DEVICE TH
 US YOU MUST BE VERY CAREFUL WHEN SOLDERING THE PARTS
 TO  THIS  DEVICE.   IT  IS A LITTLE DIFICULT TO ACTUALLY  DRAW  A
 SCHEMATIC ON A 80 CHARACTER SCREN USING LIMITED GRAPHICS BUT WILL
 GIVE IT A TRY.
                                         TO GND_____________
                                                           ]
                                                          ___
                                                C2     C3 ___
                                             ']]'          ]
                                            ]    ]    _____]__9V+
                                            ]    ]    ]    ]
                         '   '    '    '    '    '    '    ]
                         -------------------------------   ]
                        ]7   6    5    4    3    2    1 ]  ]
                        ]                               <  ]
                        ]8   9    10   11   12   13   14]  ]
                         -------------------------------   ]
                         '   '    '    '    '    '    '    ]
                                  ]    ]                   ]
                     --] ]--------]    ]                   ]
                     ]C1    R2         ]         R1        ]
           GND ______]___/\/\/\/\______]_____/\/\/\/\______]
 
 
      THIS IS A DIAGRAM OF HOW TO LOCATE THE DIFFERENT PINS ON THE
 CHIP PLEASE NOTICE THAT PIN ONE IS THE CLOSEST TO THE NOTCH ON TOP
 OF THE CHIP.  THE FIRST THING WE'LL DO IS TO CONNECT POWER TO THE
 CHIP  (REMEMBER  THAT  YOU NEED TO BUILD TWO OF THESE  TO  GET  A
 COMPLETE  SYSTEM) THIS IS ACCOMPLISHED BY CONNECTING THE POSITIVE
 WIRE OF THE BATTERY LEAD TO PIN 1 ONE LEG OF R1 AND R2 IS  SOLDER
 TO PIN 11 THE OTHER LEG OF R1 GOES TO PIN 1 OR TO THE POSITIVE OF
 THE BATTERY.   THE OTHER LEG OF R2 GOES TO GROUND, C1 GOES BETWEEN
 PIN 10 AND GROUND.
  THE TIMING CAPACITOR OR C2 GOES BETWEEN PINS 2 AND 3 OF THE CHIP
 PINS 8 AND 9 SHOULD BE GROUNDED TO GROUND.  PIN 14 IS THE OUT PUT
 AND  THIS  IS WHERE ONE LEG OF C4 (C3 GOES ON THE OTHER  VCO)  IN
 SERIES  WITH R3(THE SAME GOES FOR THE OTHER VCO) AND TO ONE  LEAD
 OF THE SPEAKER.
 
 
      THE TRIMMER POTS P1 TO P10 SHOULD BE GROUPED IN GROUPS OF  5
 POTS  EACH. THE WAY YOU GROUP IT IS BY SOLDERING ONE END OF THE
 POT TO EACH OTHER LEAVING THE WIPER AND THE OTHER END FREE.
 
                    ] THIS END GOES TO PIN 6 OF THE CHIP
                    ]
       _____________]_____________
        /     /     /     /     /
        \     \     \     \     \
        /<-   /<-   /<-   /<-   /<-
        \ ]   \ ]   \ ]   \ ]   \ ]
        / ]   / ]   / ]   / ]   / ]
          ]     ]     ]     ]     ]
          ]     ]     ]     ]     ]
        P1      P2    P3    P4    P5
 
 
      AND FINALLY THIS IS THE WAY EACH KEY SHOULD BE WIRED.
 
                  DIODE
      TO PX  ---- -->]-----]            THIS IS THE CONTACT OF  THE KEY
                          ]--------- \------
      TO PX  ------>]-----]                ]
                  DIODE                    ]
                                         -----
                                          --- GROUND
                                           -
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Используются технологии uCoz