Technical Communications Corp TTC) (home page) makes a number of encryption devices for voice and data communications. Patent 3610828
Privacy communication systemtalks about the simple and analog voice systems that use time and/or frequency shifting (easy to break) and the complex systems that do the encryption in the digital domain (expensive). They then describe a new type of system where they use digital pseudorandom signals to modify the audio signal thus achieving a more secure system at lower cost.
This Communications Security Device is intended for use with either voice or data by selecting which one using a front panel switch. It does not have a FILL port, but instead uses 5 thumbwheel switches to set a code that must be set the same on all devices in a network.
There is no provision for a battery either as main power or as keep alive. The primary power comes through the 14 socket connector that's the same as the POWER connector used on the PRC-25, PRC-77 radios and you can use the Power Connector Kit to make a cable for it.
The front panel connector has 14 sockets.
Headphone Hi In
3 Vpp 500 Ohms
Push To Talk
Mike Hi Out
15 mVpp 200 Ohms
Power to CSD909
Mike Low Out
Headphone Low In
Fig 1 5 digit code wheels and variable caps for Rx In, Tx out, Rx out
Top board has analog circuitry.
2nd board down has micro processor or controller
3rd board down has thumbwheel switches & 4 MHz oscillator for uP/uC, Red pushbutton switch S9
bottom board has many ICs (maybe digital or analog).
Privacy communication system, (TCC),Oct 5, 1971, 380/260, 380/274, 380/275 - a pseudorandom phase, either 0 or 180 deg, is modulated on the audio.
3723878 Voice privacy device, (TCC), Mar 27, 1973, 380/39, 380/44, 380/275 - classical invert then code word phase modulation
Voice privacy system with amplitude masking, (TCC),Mar 25, 1980, 380/39, 380/35 -
"A simple illustration is a number count of one to ten. Under most conditions, a listener, by analyzing the cadence of a scrambled signal, can determine that a series of numbers is being counted, even though the frequency content of the signal has been severely disturbed."
Secure communication system with improved frequency-hopping arrangement, (TTC),Jun 30, 1981, 380/34, 380/38 - stepped LO inversion
Secure facsimile transmission system using time-delay modulation, (TCC),Jul 5, 1983, 380/243, 380/218, 380/216, 380/35 - ditigitizing FM modulated fax then using PR time delay
4433211 Privacy communication system employing time/frequency transformation, (TTC), Feb 21, 1984, 380/36, 380/269, 380/276, 380/28 -
CV4228 PC to SINCGARS Fill Cable
F91120 BER Test Set
FS-5000 Spy Radio
KD-100 Key Tape Disintegrator
KYV-2 Secure Voice Module
KY-38 Man Portable Secure Voice System
KY-57 Voice Transmission Security Device
KY-65 Voice Encryption Unit
KY-68 Secure Field Phone
KY-99 Advanced Narrowband Digital Voice Terminal (ANDVT)
MSC-2001 Voice Encryption Unit (VEU)
MX-18290 Fill Device
USM-481 VINSON Interconnect Test Set
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page created 8 Nov 2013.