316 lines
18 KiB
Plaintext
316 lines
18 KiB
Plaintext
<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
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< >
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< The United Phreaker's Incorporated Proudly Presents >
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< >
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< Music On Hold Adapter (Music Box) >
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< >
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< By: The Lost Avenger >
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< >
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< An Upi Production 1990 >
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< >
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<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
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Reprinted In File Form On March 4, 1990
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Orignally Publised In Radio Electronics August 1989
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===============================================================================
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Music On Hold Adapter
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By Steve Sokolowski
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Have you ever been in the middle of a phone conversation, and need to
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either walk away for a couple of minutes or switch lines? The kids might be
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crying, the washing machine might need fabric softener, whatever. Here's an
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inexpensive "Electronic hold button" controlled by a Touch Tone phone, with
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provision for audio for the other party, using either a music synthesizer IC
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module or a radio.
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Unlike normal hold buttons, this one doesn't cut your phone handset off
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from the other party; you can still hear one another, ans also the audio, if
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you use it. Rather, what it does is let you provide this audio to the other
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parrty, and then lets you hang up the handset without losing your party; you
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can also opt for silence. When you wish to resume conversation, pressing the
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pound (#) key shuts off the audio if used, and allows you to hang up and
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disconnect when you need to know how hold buttons and Touch Tone phones work.
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Placing A Call On Hold
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The normal on hook voltage of a phone line is about 50 volts, depending
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on particular central office equipment. When you lift a phone's handset, 600
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ohms is place acriss the phone line, dropping the voltage to 5 volts.
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The hold adapter prevents a disconnection when you hang up the handset,
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by placing R6 And LED1 across the phone line using RY1. The synthesizer
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provides music for the party on hold; it can be left out if desired.
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Touch Tone Operation
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Touch Tone Phones produce Dual Tone Multi Frequency (DTMF) signals,
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using a 4 X 4 keypad that produces two tocuh tone sinusoidal outputs. The
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frequencies are determined by the key row and column (see Figure 1); The row
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frequencies are lower than those of the columns, and a Touch Tone signal is the
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sum of both. Normal Touch Tone pads have 12 keys, but the operator console
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keys (A-D) which normally aren't used.
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Adding two sinusoids is equivalent to multiplying two sinusoids whose
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frequencies are the difference if the orginals. Early Touch Tone pads used
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indicators and capacitors; modern versions are crystal controlled intergrated
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circuits that create staircase sinusoids.
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Circuit Description
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The G8870 represents each tone pair as a 4 bit code, where the column
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of a key is the first two bits, and the row of a key is the second two bits;
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both pairs of bits range from 00-11. This 4 bit code is then decoded by a 4514
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4 to 16 decoder (IC3) to give the digit dialed.
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Pressing the (*) key on a Touch tone phone adds a 1209Hz sinusoid (a
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Row 4 tone), and a 941 Hz sinusoid (a Column 1 tone), to give a binary code of
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1100. Similary, pressing (#) key adds 941Hz And 1477Hz sinusoids, to give a
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binary code of 1100.
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If a user preses a key on a Touch Tone phone used to operate the hold
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adapter, pin 15 (Strobe S<>D) Of IC1 goes high. That stobe output is inverted
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by NOR gate IC2-a, and is fed to pin 23 (INHIBIT) OF IC3, enabling that device.
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If The Touch Tone key pressed is either (*) or (#), then either pin 19 or pin
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14 of IC3 goes high, since those are the pins corresponding to these keys. Pin
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19 of IC3 goes to pin 12 of IC2-b, and pin 14 of IC3 goes to pin 5 of IC2-c.
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Note that IC2-b and IC2-c are used to create a NOR gate reset set (RS)
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flip-flop, which then controls RY1.
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Since only one Touch Tone Key is interpreted at a time, there's no
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mormal instance when both pin 19 and pin 14 of IC3 fo high simultaneously; that
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only happens when IC3 is deferctive or there's a short. If neither the (*) key
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nor the (#) key have been pressed, then both pins stay low. Pressing the (*)
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key drives pin 12 Of IC2-b high and pin 11 of IC2-c goes low. Similarly
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pressing the (#) key drives pin 5 of IC2-b high and pin 4 of IC-b goes low.
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When pin 4 Of IC2-b, goes high by pressing the (*) key, Q1 turns on and
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the contact of RY1 closes, preventing a disconnection when you hang up the
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handset. That's because phone line current now flows through R6, the secondary
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of T2, and the hold indicator LED1, which is now lit. When pin 4 of IC2-b goes
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low by pressing the (#) key, Q1 turns off, current stops flowing through the
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coil of RY1 (opening its contact), and disconnecting the hold adapter. The
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hold adapter doesn't work as a standard hold button, because pressing the (*)
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key doesn't disengage your phone handset. It just lets you hang up or switch
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to another lone without being disconnected, because a second current path is
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now across the phone line.
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To include audio, the music synthesizer module goes in parallel with
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LED1, and the audio fed from the synthesizer to the primary of T@. The audio
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modulates the 5 volt phone line voltage and is heard by both you and the party
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on hold. If you prefer either dialogue or some other music, you can replace
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the synthesizer with a radio that has an earphone jack.
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To do that, plug an external earphone cord into the jack, and connect
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an earphone jack to the PC board hole for the synthesizer output, using S2 (an
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SP3t switch) as indicated. For silence, jumper the secondary of T@; that can
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be done using either a jumper or S2, although the use of S2 is strictly
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optional. Just remember that pressing the (*) key lets you hang up without
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being disconnected, but doesn't disengage the handset. The hold adapter uses
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IC4, a 7805 5 volt DC regulator with C4 as filter, and 12 volt DC, 250mA, wall
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transformer T1; S1 is used as the ON/OFF switch.
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Construction
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User sockets for the IC's, transistor (if desired), and relay. Any
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suitable cabinet will do, and user a 1 amp, 120 volt to 12 volt DC wall
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transformer. Use screws and spacers or adhesive foam to attach the PC board to
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the cabinet. You can use any SP3T switch you want for S2, as long as it'll fir
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in the cabinet.
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Music synthesizer modules play repeating 30 battery socket and speaker.
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The 1.5 volt battery socket and speaker. The 1.5 volt battery will likely be
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present; the speaker may be, depending on the model. Note the polarity of the
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battery (if present) before removing it.
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The mechnical ON/OFF switch depicted is a metal flap, riveted on the
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the right end, and with the left end on the right end, and with the left end
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resting against the module board by spring tension. Connect the pad on the PC
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board labeled "1.5 V" to the synthesizer's battery terminals, break the speaker
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wires or foils (if the speaker is present), and the solder any ON/OFF switch
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closed. Attach the synthesizer to the PC board using doublesided tape or
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adheasive foam.
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The two PC board pads underneath the "1.5V" label connect the audio to
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the primary of T2. The secondary of T2 goes in series with R6 and LED1, adding
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audio to the 5 volt DC offhook voltage. For silence, jumper the secondary of
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T2. To display all 10 decoded Touch Tone keys, install R9 to R18 And LED2 to
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LED11 (with bezels), the former mounted in the PC board, the lattered mounted
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on the the front panel of a cabinet.
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Installation And Test
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Connect the red and green wires of a standard phone cord to their PC
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board locations; the yellow and black wires aren't used. The other end plugs
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into a T adapter with two RJ-11 female telephone sockets feeding into one RJ-11
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male telephone plug. Plug the hold adapter and the Touch Tone phone into the T
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adapter, and plug the T adapter into the telephone jack.
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To test the hold adapter, dial a friend; if R9 to R18 and LED2 to LED
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11 were used, the LEd corresponding to the Touch Tone key pressed should light.
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To place a call on hold, press the (*) key; RY1 will close, connecting R6 and
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LED1, audio should now be heard by you in the handset if the synthesizer or a
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radio is present, and you can now hang up the handset. Pressing the (#) key
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disengages the hold adapter, opening RY1's contact, disconnecting R6 and LED1,
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and stopping the audio. Since the current path had now been removed, hanging
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up the telephone will disconnect your party, unless you first press the (*) key
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again.
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Figure 1:
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Touch Tone Keypad
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1209Hz 1366Hz 1477Hz 1633Hz
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<20>-------------------------------<2D>
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697Hz | 1 2 3 A |
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770Hz | 4 5 6 B |
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852Hz | 7 8 9 C |
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941Hz | * 0 # D |
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<20>-------------------------------<2D>
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Schematics To Music Box:
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Parts Needed
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-=-=-=-=-=-=
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Resistors
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=-=-=-=-=
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R1, R2, R4 - 100,000 Ohms, 1/4 Watt, 5%
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R3 - 47,000 Ohms, 1/4 Watt, 5%
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R5 - 50,000 Ohms, 1/4 Watt, 5%
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R6 - 120 Ohms, 1 Watt, 5%
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R7 - 220,000 Ohms, 1/4 Watt, 5%
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R8 - 1,000 Ohms, 1/4 Watt, 5%
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R9 To R18 - 1,000 Ohms, 1/4 Watt, 5%
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Capacitors
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=-=-=-=-=-
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C1, C2 - 0.01 <20>F Disc
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C3 - 0.1 <20>F Disc
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C4 - 470 <20>F 16 Volt Axial Tantalum Electrolytic
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Semiconductors
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=-=-=-=-=-=-=-
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Q1 - 2N222 Transistor
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IC1 - California Micro Devices G8870 Touch Tone Reciever
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IC2 - 4001 Quad NOR Gate
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IC3 - 4514 1 of 16 Decoder (High Output)
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IC4 - 7805 5 Volt DC Regulator To 220 Type
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LED1 To LED11 - Standard Red LED's
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Other Components
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=-=-=-=-=-=-=-=-
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S1 - SPST 120 Volt AC Switch
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S2 - SP3T Rotary Or Slide Switch
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T1 - 120 Volt AC To 12 Volt Dc, 250 mA, DC Wall Transformer
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T2 - Audio Transformer, 1000 Ohms Primary, 8 Ohms Secondary (Mouser
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Electronics, Catalog NUmber 42tm013)
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RY1 - 6 Volt SPST Relay With 100 Ohm Coil
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XTAL1 - 3.58 MHz Crystal
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MODULE1 - Music Synthesizer Module
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Miscellaneous
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=-=-=-=-=-=-=
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Suitable Cabinet
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4 Wire Phone Cord With Open Wires On One End Or Spade Lugs
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4 Prong Or RJ-11 Modular Male Plug On The Opposite End
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Dual RJ-11 Socket To Single RJ-11 Plug T Adapter
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Female To Female Rj-11 Adapter
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Solder
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Wire
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NOTE: A kit of parts is available from De-Phone Industries, PO Box 5835,
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Spring Hill, Florida 34606. The kit includes the single sided PC board
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($7.50 US), G8870 Touch Tone Receiver IC ($10.00US), T Adapter
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($2.20US), 3.58 Mhz Crystal ($1.75US), And Music Synthesizer Module
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($1.75US); Send $15.70US for all parts. Allow 3-4 weeks for delivery,
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and include $2.50Us for shipping/handling. Florida residents include
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sales tax; Canadian residents send money order in US funds, with $3.25
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shipping/handling. No personal checks, please.
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<20>------------------------------------------<2D>
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|<7C>-----------------------------------------ſ
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<20>---o Green || 1<>-------<2D> ||
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| || <20>-<2D> Ic2-a |3 ||
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| <20>-o Red +5V || <20>----------------o | 4001 0----------<2D> ||
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| | <20>----------<2D> || | <20>-<2D> | | ||
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| o-C1-R1-o-----|1 IC1 18|-o || | +5V 2<>-------<2D> +5V<11>| ||
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| | | | | C3 || | <18>-------------------------------<2D>|| ||
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o-<2D>-C2-R2-<2D>-o---|2 17|-o || | <20>|1 Strobe Ic3 24|<7C>| ||
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| | | o---|3 | R7 || | | Data1 4514 Inhibit 23|-<2D> ||
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| | R3 R4 | 16|-o ||<7C><>---|2------<2D> <20>-----------<2D> | ||
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| | <20>-<2D>---|4 15|----<2D><><EFBFBD><EFBFBD> | <20>-| Latch 1 |--<2D>Data4 | ||
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| | <20>-o---|5 14|----<2D>|| | Data2<61>-| |-<2D><>----22|---<2D>|
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| | | <20>---|6 13|-----<2D>| <20>--|3------<2D> <20>-<2D>--<2D>--<2D>--<2D><> | | |
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| | Ground | 12|------<2D> | | |A |B |C |D |Data3 | |
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| | <20>---|7 11|--------<2D><>-|4-(7)----<2D>-<2D>--<2D>--<2D>--<2D><> <20>-----21|----<2D>
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| | Xtal | | <20>---<2D>-|5-(6)----| |---(0)-20|----<2D>
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| | <20>---|8 10|<7C> <20><>---<2D>-|6-(5)----| 4 To 16 |---(*)-19|-<2D> |
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| | <20>---|9 || <20><><EFBFBD>---<2D>-|7 (4)----| Decoder |---(8)-18|-ſ |
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| | Ground<6E>----------<2D>| <20><><EFBFBD><EFBFBD>---<2D>-|8-(3)----| |---(9)-17|-<2D>ſ|
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| | +5V-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>---<2D>-|9-(1)----| |-------16| ||||
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| | o-----<2D><>-----<2D> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>---<2D>-|10-(2)---| |-------15| ||||
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| | 4| || |11 ||||||<7C>--<2D> | | |---(#)-14|<7C>||||
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| | <20>--0--<2D> || <20>--0--<2D> ||||||| |11-------| |-------13||||||
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| | |Ic2-c| || |Ic2-b| ||||||| <20>-|12-------<2D>-----------<2D> ||||||
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| | |4001 | || |4001 | ||||||| | <20>-------------------------------<2D>|||||
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| | <20><>---<2D><> || <20><>---<2D><> <20>-<2D>||||||Ground <20>-------------<2D>||||
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| | |5 |6 || 13| 12| |<7C>-<2D>||||<7C>-------------------<2D> |<7C>-------------<2D>|||
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| | | <20>---<2D><> | | ||<7C>-<2D>||<7C>---------------<2D> | || |||
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| | | <20>----<2D> | |||<7C>-<2D><>-----------<2D> | | || <20>-----------<2D>||
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| | | <20>---<2D><><EFBFBD><EFBFBD>--------------<2D>----<2D>----<2D>---<2D><> | <20>-------<2D>|
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| | | |||<7C>---------<2D> | | | | | | |
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| | | ||<7C>-----<2D> | | | | | | | <20>--<2D>
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| | | <20>-<2D><>-<2D> | | | | | | | | |
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| | | R9 R10 R11 R12 R13 R14 R15 | R16 R17 R18
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| | | |(1) |(2) |(3) |(4) |(5) |(6) |(7)| |(8) |(9) |(10)
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| | | Led2 Led3 Led4 Led5 Led6 Led7 Led8 | Led9 Led10 Led11
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| | | | | | | | | | | | | |
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| | | <20>----o----o----o----o----o----<2D> | <20>----o-----<2D>
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| | | Ground | Ground
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| | <20>----------------------------------------------------<2D>
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| <20>----------------<2D>
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<20>--------<2D> |
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<20>-----<2D> | |
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| RY1 0 | |
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| 0-<2D><> <20>----------------------------<2D>
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| 0-<2D>------<2D> |
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<20>-----<2D> | +15V| |
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<20>--<2D>--<2D> | |
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<20>---| RY1 || | |
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| | Coil|<7C> | |
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| <20>-----<2D> | |
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| <20>Ground | |
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| | | <20>---------<2D>| <20>-----------<2D>
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<20><>---<2D><> R6 <20>---| Radio || o----| 120 Vac |----<2D>
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| Q1 | | 0 Slience |<7C>--| || | | to 12 Vdc | |
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| | A| S2 0 Radio---<2D>| <20>---------<2D>| | | 25mA | |
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<20>--<2D>--<2D> <20>----o <20>0----0 Music | <20>---------<2D>| 120 Vac | Wall | |
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| | | | <20>---------<2D>--|Module 1 || | |Transformer| |
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| | Sec T2 Pri <20>---------o--| || o----| T1 |-<2D> |
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| | | | | <20>-<2D>------<2D><>| <20>-----------<2D> | |
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| <20>----o <20>-----<2D> |- +| | Out<75>-----<2D>In | |
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| B| | 1.5V | | <20>---o--| Ic4 |--0--0--<2D> |
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| | | | | | | | 7805| 0 S1 |
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| <20>-Led1-o-----------------------<2D> | | | +| | | |
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| <20>-------------------------------------<2D> | | C4 <20>--<2D>--<2D> |
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<20>--------------------------------------------<2D> | | |Gnd |
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| | | |
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| <20>-----o--------------<2D>
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0 Ground
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5 Volts
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You may distrubute this file freely but may not change any part of this file in
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whole or part without the written or verbal concent of the author.
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===============================================================================
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Call These Great Upi Boards!
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===============================================================================
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Node Number Board Name Sysop Baud
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===============================================================================
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Hq 416-Upi-Home The Northern Phreaker's Alliance The Lost Avenger 24
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1 416-Upi-Nde1 The Shining Realm FrosT BitE 24
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2 514-Upi-Nde2 The Order Of Kamikaze Tomcat 96
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3 305-Upi-Nde3 Ferrari Mr. Ferrari 38.4
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4 416-Upi-Nde4 Time Zone Destoryer 38.4
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5 716-Upi-Nde5 The Knight's Society Jeff Knight ?
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===============================================================================
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03-06-90/006 Copywrite 1990 By The Lost Avenger-All Rights Reserved
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Downloaded From P-80 International Information Systems 304-744-2253 12yrs+
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