192 lines
7.9 KiB
Plaintext
192 lines
7.9 KiB
Plaintext
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<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
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<> The BAD BOY'S (tm) and ABuSe <>
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<> Presents 'How to Build a Telephone Scramber ' <>
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<> By Bloodwing ->BB<- <>
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<> Thx to Casual and Crusader <>
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<><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
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Telephone Scrambler
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-------------------
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\Protect your confidential telephone calls against intrusion with/
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\this easy-to-build scrambler. /
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Scrambling is the most effective method for eliminating unwanted evesdropping
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on your confidential calls. It should be considered if you have reason to
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believe that unauthorized persons are or could be listening in. A system
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consisting of two compatible telephone scramblers will permit normal
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conversation between you and your intended listener, while making all speech
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unintelligible to anyone listening in at either end of the line. Only persons
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with a compatible unscrambler will be able to understand what is being said.
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(Fig.1)
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Complete telehpone security is obtained with a TVS250 at both ends of the
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phone line forming a duplex scrambler/descrambler system.
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[Headset]-[TVS250]-[Phone]-[Phoneline]-[Phone]-[TSV250]-[Headset]
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:Circuit Design:
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The COM9046 voice scrambler/descrambler IC contains a crystal oscillator that
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that controls system timing. The onchip oscillator requires an external 3.58-
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MHz crystal that is commonly used in TV color-burst applications. The chip
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also contains switched-capacitor filters, so input speech must be filtered by
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an anti-aliasing single-pole, low-pass filter before it is applied to the
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audio input.
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:Parts List:
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All resistors are 1/4-watt, 5%, unless otherwise noted
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R1 100,000 ohms, PC-mount potentiometer, screwdriver adjust
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R2 500,000 ohms, PC-mount potentiometer, screwdriver adjust
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R3,R4 10,000 ohms
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R5,R6 3900 ohms
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R8,R9 100,000 ohms
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R10-R13 1000 ohms
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R7,R14,R15 51,000 ohms
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R16-R18 2200 ohms
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R20 150,000 ohms
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R21 5100 ohms
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Capacitors
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C1,C2 15 pF, ceramic disc
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C3-C10 0.1 uF, metal film
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C11,C12 2200 pF, ceramic disc
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C13-C15 0.001 uF, ceramic disc
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C16 1uF, 35 volts tantalum
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C17,C18 10 uF, 16 volts, electrolytic polarized
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Semiconductors
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IC1 COM9046 voice-scrambling IC, (Standard Microsystems)
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IC2 MC34119, audio amplifier driver (Motorola or equiv.)
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IC3 LM358 dual operation amplifier, single supply
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IC3 78L05A, 5-volt regulator (Texas Inst. or equiv.)
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Q1 2N2222A, NPN transistor
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LED1 green light-emitting diode, T1, 5mm
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LED2 red light-emitting diode, T1, 5mm
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Other Components
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S1 SPST slide, PC-mount, side-actuated switch
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S2 SPST slide, PC-mount top-actuated switch
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S3-S6 STS2400 PC, 2P4T slide, PC-mount, top-actuated (Augat/Alcoswitch or
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equiv) switch
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J1,J2 telephone jack 4-4, Type 616, PC-mount
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JU1-JU4 two-post jumper, 3/32 inch-on-center with insulated shorting clips
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XTL1 crystal 3.579545 MHz, metal case (ITT 4183 or equiv.)
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B1 9volt transistor battery, alkaline, standard
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Miscellaneous
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TVS250 PC board, 5-inch length of telephone cord terminated with standard
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telephone plugs, 9-volt transistor battery clip-type holder (Keystone No. 79
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or equiv.) with two 2-56 screws and nuts, 9-volt transistor battery terminal
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snap with leads, four rubber or plastic PC board feet and solder.
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:Note:
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The following parts are available from Securicom, P.O. Box 5227, Chatsworth,
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CA 91313-5227 (818) 710-0110
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* COM9046 scrambler/descrambler IC only - $18
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* Double-sided, silk screened and drilled PC board - $20
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* A complete kit including PC board, all components, and 5 inch plug-
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terminated phone cord - $59.95
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* Assembled and tested TVS250 with user's manual - $79.95
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(Fig.2)
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+5V
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| |--|
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o------| |-----~--o---
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2.2k R17~ R4~10k | R2 |
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o---<>-o----|--*+**** | R11 R5
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| C3 | | *IC3a*---o--~---<>---o--~------o--(3)
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MIC+-----0^0| | o--*-**** C4 | |
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JV4 | | | C11$
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R3 ~ | C5 | R6 |
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MIC------0^0-------| |---~---<>--# |-<>-o-|--~---o-----(2)
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JV3 # R21 C8 | | | C12$ |
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| | | |--| (Cont fig.3)
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Base audio Signal------------------------| | | #
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R8~ ~R9
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Base audio GND------------------------# | |
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--o---------o--(1)
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(Fig.2)
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S1 ******
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|---@----* IC4*---o--o--o-->+5v
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| ****** | | |
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| | | | ~R13
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= | C10<> <>C17
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|B1 | | | |
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| | | | L LED Green
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=----------0------o--o--|
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#
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(Fig.3)
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C1 XTAL +5v
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--<>--o-&-o---<>- ^
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# o-~-o # |---o
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|R19| | |
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******* | L LED2
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3--* * | ~ R10
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* *------|---o--S2----------------#
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2--* IC1 * | |
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* *------|-| <>C6
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* * | | # R20 /JV1--
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* * | |---------~-------Q1 Mic Input to Tele Base
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* * | \JV2--
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* *------|---|
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* * | |
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* * | |
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* *--o---o |
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1--o--* * | | |
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| *******--| | |
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| o o R18~ ~R14 C14
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| |---|--<>---o o---------<>---------------|
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| | | C18 | | ^+5v |
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| | | | | R15 | |
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| | o--<>---o |---~-----o-----******* |
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| | | C7 | | *IC3-b* |
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| | # | C13<> *+ *----o
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| | | | * * |
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| |-----------o # * * |
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|---------------| C9 *- * |
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<>----~---o--******* |
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-------~---------| R12 | | |
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| R7 | # |
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| C15 # |-------------|
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| |--<>---|------|
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|--------o---****|**** | Handset speaker
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| * *--|------------------>
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---------|---* IC2 * |
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| | * * | Handset speaker
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<>C16 | * *--o------------------>
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| |--|---********* |
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o-----| | R1 |
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# |----o---~-----|
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------------------------------------------------------------------------------
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(~)=Resistor
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(<>)=Capacitor
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(@)=Simiconductor
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I recomend that you call and purchase a better diagram for the TVS250 from the
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company listed above. Remember, to make the scrambler work you must have two
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TVS250's, one on the callers phone and another on the receivers phone. I
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haven't purchased a set yet, but this DOES work, information was gathered from
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radio electronics. So, it is a reliable source, not just another dumb text
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file. Good luck! ->BB<-
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