CON S TRšC TION
    
    [hc~ ~ltIt' 1~Ž I'~'S t~o t~`s per digit. '~e
    sh~w nne t,~-i 11:~`r an`! a co~nmor~ an~'ZliFicr,
    h<'t h l~t' i r~g t u r nL kl `~' wh~ 't ~ I,e pushhu t t on
    
    ~n~ls .~\ thru ti~` ;IlL)LILS' O!Z~ for e.teh of
    the t,~u `~-citI;linrstEnr tI,at l.uttons di`~`t)
    .l~l~l n~c l`'r tl~c~ :'nrplit~icr. .`l. ~lioJc~ are
    tlit"lt t,~' :~] L`IZ-01 ~ ~hit LIZ ('IZ tI`c .aml, Iets
    
    ~ L'~! [' ~ t' i111 1 \ _ I ~ ~,~.t t ~ I\L~LI ~ j l j C OIZ ) . Fl~t. `\C~ t
    - 1~'.t ~t' ~ i ~ .' t U I C J1lliUlL' t'.' ~ |) i CCt', li.~L IZ t (~'
    
    ' i W` t IZI-~, ;' I . ~ ~ L ~ j j t k) ~ . .~'~K SC t ~ <;' i !~ .
    ''r i ~ t t'~! ~ L`~It \~~.' j'; ''r~`l`~- 10 ~'i I I i.~'l`~.
    
    ™SC i ll.it<~t t leq~e'~ ~ - lt~. ll~C,wher~ tI~'
    k/~ ~ ~t is i~l j~`ste~l t~, cl~e point of oseil-
    I.1t ic~n. This paint h.ls no dist`~rt-ion, and
    (IW 1~lC~rlC\! C~' L;C IL1i~U~L ~listorticn
    ~{ S ;~. FOr 1SL)LI us: Jes,an`1 ~ .L}022, R=
    .lbant lt,l~ul~'ns. Raisi', l R to I ~K(the nexc
    llitl}test St .\Uda - 'Z val~le) lower i the freq-
    ueney, and yau can now tunc u~ to 1500 E{~.
    Dist`~rti~ `.,ill be very l~w.~C wil1 le
    
    (10-1., .lnd R/2 will be 22X, 5a use a 50K
    pot. Witn S~r'~'e 1~21 capacitors, ti~is
    Twin-T ú .;.illator is re_lly úJOCu. Try it!
    
    To si~nplity the ~iiede jungle, use a n~arrix
    by sa~ldwichirlg the di`~'es between two pieces
    af perforated circuit board, one witl~ 13
    "buss"li~Zes to the swiraties arZd the other
    witiZ t~ output lines, 7 for oscillators and
    or~e for the a;`plif ier. ActucZlly, since 2600
    is a sin~le tone, you don't need a diode for
    it, so rnatrix can bc 12 X 7 The diodes are
    uprigt~t inside tt,e two boards. Watch polarity.
    
    Readers Z,rave reparted that an integrated
    circuit exists that use I a resistor for
    eech t one, two va riable osc i llat ors be ing
    required for a box. TIZe Signeties 566 is
    also reported to be unstable wich tempera-
    ture variae ic~'s. For plans on bu ilding with
    it, Write to Sign~tics,811 E. Arques Ave.,
    Sunnyvv~le, Ca. t3- 066 a~Zd ask for information
    on ti~e 56b VCO and applications notes. Sign
    your name Joe Smith, Enq.
    
    T UN I NG
    
    Notes on an organ will actually wor}` if
    you use thern, but they~re best used for
    tuning. Or,use a touct~ tone ph.one for
    tuning your box, cr your signal gener-
    ator. Play your osciLlatcr and yc~ur source
    of p~tch and adjust till t'beats" ~ust stop.
    Remember there are two tones per digit.
    If you tune wich an organ, you must be able
    to interpolate, that is to set the pitch in
    between two different orgah notes. To set the
    900 oscillator, it shouid be between the A and
    the A#.
    
    OPERATION
    
    Fron~ ~ p~y phone,~al long distance info-
    rmation, or an 800 numher, whichever you
    can get. from vour city. As call goes thru,
    prcsc 7600 f~r one seconJ, and when you
    hear a clicl; ~tial desire] nu~ber, preceel-
    ed hy k17 and followed by ST. E-xample-
    ki7415686991~ST. Each pulse i~ the sa~e as
    if ~nll werc using .a pushbutton phone. A11
    pu~ses must he sent within 10 seconds of

    





    disconn„ct, if not, disconnect and try
    again. Do not stay on longer than necessary.
    
    ~tY ,r - H8urto~
    
    _ .
    
    _ '~ ~ t' .
    
                 .      ~lk
    
    _ _ Ä Ä . _~,
    
    1.
    
    1 C
    1 ~Ä
    I ~ - ~ ~ '
    
     __ _ _ ~
    
    OlfE oselL`^ro8'
    7 NEIDRD
    Fe I
    2' P'C
    1t . n ~egehms
    C ir) ~<rofo - J~s
    
        15R   ~
    
    .021 ~R
    \\ ~ v~^
    
       11     ,
    
    _~
    
    ~ 4lK
    
    ' Lt7\(
    
      V~ 5/lOV
    ~ ~ -~]
    ~ ;~ L
    
                       71`fPt~l ~
    
    F4t,1Ec! ~ !,
    
    1
    
    ~JI ~M' \~11' ~v;~il.~l~le at 1'olvEuLs,Bo.< q17l~l`>r~fLeId,~lass. 01940
    t~r.ler 741l, 1~-5 casc, 2 lor qn½, a~lJ 25~ posta~c anl wait. hrite
    lor c;rtalo~ Ei'st as the~ ma' requLrc !'i'~iu`~n oršcr.
    Xtl resistors 1/1 h„tt,5 ~. (al~acitors ~cco'~n~cn;1eJ-Spraguc 19~1',
    sil`-crc<1 n~ic;1, or '~ic.1(lil,pe`1).
    
    The values of R shouid be between 30K œ 1501C.
    
    Hep 54, 2N2222,or RGA SK3020 transistors.
    Diodes-~.atched smali signal silicon(~9l4)
    
    7~1 OPAMP-TOPVIEW
    
                         D I P
                           ~J
                          I_~ø
    
                      Organ Notes
    
    Note l rc~llel~c~
    
       ~ 5 ~ 9 ~
       ,t  ~ ~ O
       (:` ~ ~ 09
       6   1~19
           ~0
       ~C  1661
       1 7 '637
    
    Touch-Tone
    '209 1336 1477
    
       697 1   2   3

    





       770     ~5  6
       852 7   8
       9ll *   0
    
    ro s
    
    Plt.
    DIP
    
                     Blne Box Tones
                   pJ~it I.requencies
    
        17()0~90()
        700+ 1 100
         900~1100
        ~7 0 0+ 1 3 110
        5qon+ 13DO
        ~] Inn~l300
        77011+ 1500
        sn(l~lsoo
        ~1 1 00+ 1 SOO
        01 30n~ 15~1()
        l~i'1 1 00.1 700
        ST150061700
    
    [lisconnect - 2600
    
    A 16 button keyboard with no moving
    parts, ~,easuring 3X3X 1~2, is avail-
    able f rom Environ~`ental Products,
    Box 4C6, Lafayette, In. 47902. The
    price is $7.95 but write for their
    catalog before you order it. Also,
    if any readers know wLere to obtain
    thirner keyboa~s, please write us
    with details. By the way, lG buttons
    is perfect for a comblnation blue
    box/red box.
    
    Line earpiece with fo~, ~d press it to
    mouthp iec e ti~htly.
    The smartest phone phreaks we know seldo~
    carry their unit with them, but rather a
    cassette reco~er, which they erase after
    making their call.
    All numbers directly dialable are callable
    with the box. Overscas inst~ctions will be
    forthcoming.