<=-=*=---------------------------=*=-=>
|        Blue Box construction        |
<=-=*=---------------------------=*=-=>

<=-=*=---------------------------=*=-=>
| Written by                          |
|                                     |
|            Dr. Nibblemaster         |
<=-=*=---------------------------=*=-=>

<=-=*=---------------------------=*=-=>
|                                     |
|    Hello there, well I took a look  |
| at the old blue box schems going    |
| around a few days ago, and they     |
| certainly suck! They use ancient    |
| parts which are not easy to get a   |
| hold of today. Well anyway, I wrote |
| up a new schem and built my own box,|
| it works fine and Ill be writing a  |
| schem on an apple hires screen so   |
| every one can see it. Anyways if you|
| know  some stuff about electronics, |
| and want to build a box, do not use |
| the old 2207 VCO, the best thing to |
| use is a voltage to freqency chip,  |
| otherwise known as  the LM331N.     |
| These chips are fairly expensive,   |
| but all you credit card phreaks     |
| should order about a 1000 or so from|
| an OEM distributer. Anyway, the     |
| chips are 8-pin dips, which don't   |
| take up alot of board real estate,  |
| so you should be able to fit a whole|
| blue box tacti-mem keypad and       |
| digital display in a cigarette box. |
| We don't want to look too obvious,  |
| do we? Well thats it for now.       |
|                                     |
<=-=*=---------------------------=*=-=>
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$                                     $
$           BLUE BOX PLANS!           $
$           ---------------           $
$                                     $
$       Edited and Uploaded by:       $
$                                     $
$                                     $
$$$$$$$$$$$$-=>Lex Luthor<=-$$$$$$$$$$$
$                                     $
$              Written by:            $
$                                     $
$     Mr. America from Osuny BBS      $
$                                     $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$                                     $
$                                     $
$   This file will explain the        $
$ construction, troubleshooting, and  $
$ adjustment of a Blue Box.           $
$                                     $
$                                     $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$                                     $
$   We all know that the touch tone   $
$ frequencies are composed of 2 tones $
$ (2 different freqs.) so that is the $
$ reason why we have 2 VCO's (Voltage $
$ Controlled Oscilators). We'll call  $
$ them VCO#1 and VCO#2. If you have   $
$ noticed VCO#1 and VCO#2 are exactly $
$ the same type of circuits. That is  $
$ why only 1 was drawn. But remember  $
$ that whatever goes for VCO#1 also   $
$ goes for VCO#2. Both VCO'S are      $
$ composed of a handfull of part. One $
$ chip, two capacitors, 2 resistors   $
$ and five potentiometers. All of     $
$ this will give you (when properly   $
$ calibrated) one of the freqencies   $
$ necessary (the other one will come  $
$ from VCO#2) for the operation of    $
$ the Blue Box. Both of these freqs.  $
$ will be mixed in the speaker to     $
$ form the required tone.             $
$                                     $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$                                     $
$   This is one of the most           $
$ sophisticated designs I have ever   $
$ made. Why?. Because other designs   $
$ will drain the battery after 10     $
$ calls. This design will make them   $
$ last 10 months!!!!!!. But never the $
$ less, don't forget to put in a      $
$ switch for on and off. Ok let's     $
$ build the two VCO'S and calibrate   $
$ the unit before we get to the       $
$ keyboard construction.              $
$                                     $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
<                                     >
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
!                                     !
!          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  .
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 means 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 %
% 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.              +
+                                     +
+-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-+

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