Ramsey Electronics SS70A manual

SS70A • 1 SPEECH SCRAMBLER / DESCRAMBLER KIT Ramsey Electronics Model No. SS70A Communicate in privacy over any audio path! Full duplex operation so this uni t can scramble and descramble at the same time! E-Z hookup instructions for radio, or scanner. • Uses “state of the art” digital electr onic filtering for superior noise free sound! Sp[...]

SS70A • 2 RA M SEY T RA N SMIT TE R K ITS • FM100B Professional FM Stereo Transmitter • FM25B S yn thesi zed Stereo FM Transmi tter • MR6 Model Rocket Track ing Transmitter • TV6 Television Tra nsmitter RAMSE Y RECEI VER KI TS • FR1 FM Broa dcast Receiver • AR1 A ircraft Band Recei ver • SR2 Shortwa v e Receiver • SC1 Shortwav e C[...]

SS70A • 3 SPEECH SCRAMBLER / DESCRAMBLER KIT Ramsey Publication No. SS70A Price $5.00 TABLE OF CONTENTS Introduction to the SS70A ............. 4 Circuit Description ...... ................... 5 Parts List .................... ................... 7 Schematic Diagram ................. ...... 8 SS70A Assemb ly instructions ....... 9 Testing the SS7[...]

SS70A • 4 INTR ODU C TION The Ramsey SS70A is a complete tw o-way speech scram bler/descrambler with suitable inputs and output s fo r sc anner, two-wa y radio, cordless telephone, or tape recorder operation. It is designed to help the user secure total privacy for communicat ions or recorded memos. Just as its scram bling, technicall y called ?[...]

SS70A • 5 The audio in put is am plified and f iltered by the IC, then "m ixed" with the carrier to produce both the sum and di fference frequencies. For example, a 500 Hz input mixed with the 3 KHz carr ier will produce signals at both 2500 Hz and 3500 Hz and a 1KHz signal will produce a 2 KHz and 4 KHz result. The outputs are now low [...]

SS70A • 6 RAMSEY Learn-As -You-Build KIT ASSEMBLY There are numerous solder connections on the SS70A printed circuit board. Therefore, PLEASE take us seriousl y wh en we say that good soldering is essential to the proper operation of y our scrambler! Follow ing, are a few quick tip s to make the asse mbly process a bit more enjo yable. • Use a [...]

SS70A • 7 SS70A PART S LIST Sort and “check off” the c omponents in the boxes provided. It’s also helpf ul to sort the parts into separate containe rs to avoid conf us ion while assembling. RESISTORS AND POTENTIOMETERS  1 2 ohm resistor [red-black-gold] (R13)  1 10 ohm resistor [brown-black-black] (R6)  1 100 ohm resistor [brow n-b[...]

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SS70A • 9 SS70A ASSEMBLY INSTRUCTIONS  1. First, install s witches S1, S2, and S3 . Be sure th at all legs fit through the circuit board before soldering. Sold er all the pins.  2. Install the volume co ntrol pot, R11. Solder th e three component connections as well as the mo unting pins.  3. Moving to the back of the PC board, insta ll [...]

SS70A • 10 without "strain ing" the leads. Sol der all three conn ections securely.  16. Instal l R12, 1K ohm (bro w n-black -red).  17. Instal l R9, 470 ohm (what col ors were th ose?!) (yellow-violet-bro wn).  18. Install C12, a 10 uF electrolytic capacitor. This component is "polarized" and must be oriented correct[...]

SS70A • 11 done inside the chip, th is sh ould go fa irly quickl y.  32. Install C6, 22 pF disc capacitor (marked 22 or 22K).  33. Install C7, another 22 pF disc (marked 22 or 22K).  34. Install Y1, the 3. 58 MHz or 1 0.24 MH z crystal. Make sure to mount the cr y stal in the pr oper h oles.  35. Install R8, 1Meg ohm (brow n-black-gre[...]

SS70A • 12  51. Install C1 8, the last 1 0 uF. Watch that polarity !  52. Install VR1, the 7805 voltage regulator. Orient it as shown in the parts diagram, with the metal back facing edge o f the PC board as shown. T his component provides a stab le so urce of 5 volts to the MX128 IC chip, an d throughout the spee ch scram bler. CONGRATULA [...]

SS70A • 13 Configuring the SS70A inputs: LINE LEVEL INPUT  Depress pus hbutton s witch S3 OUT to the LINE positio n. SPEAKER LEVEL INPUT  Set pushbutton switch S3 to the IN position to sele ct SPEAKER level input. Configuring the SS70A ou tputs: LINE LEVEL OUTPUT  Install the jumper block between the pins on J4 lab eled “LINE”. SPEAK[...]

SS70A • 14  Set pushbutton switch S3 to t he IN position to select SPEAKER level input.  Install the jum per block between the pins on J4 labeled “SPEAKER” t o select speaker level output. Connect the scanner’s audio output to J7, RX IN and connect you r speaker to J6 RX OUT. TAPE RECORDER CONNECTION In hooking up a tape recorder, we?[...]

SS70A • 15 the message back, switch the pow er switch to “bypass” mode to hear the scrambled message. TYPICAL TW O-W AY RADIO HOOKUP: (SS70A required at e ach end) The two-way radio h ookup is com plicated somew hat by having to pay attention to the PTT (Pus h To Talk ) line of th e radio transce iver. This line “keys” the tran smitter wh[...]

SS70A • 16 TROUBLESHOOTING INSTRUC TIONS Since this circ uit contains r elatively few com ponents, prob lems are usually due to mental errors rather than component failures. Th e most common errors are in assembly , especially with the IC chips. Check for solder bridg es or splashes. Check y our parts placemen t, “Hmmm... is that resistor in th[...]

SS70A • 17 CONCLUSION We sincerely hope that you have enjoy ed the construction and use of this Ramsey Kit. As alw ays, we have tried to compose our manual in the easiest, most “user friendly” format that is possible. As our customers, w e value your op inions, comments, and additions that you would like to see in future publications. Please [...]

SS70A • 18 SS70A PART S LAY OUT DIA GRAM[...]

SS70A • 19 The Ramsey Kit Warranty Please read c arefully BEFORE calling or writing in a bout your kit. Most pr oblems ca n be solv ed without contacti ng the fac tory. Notice that thi s is not a "fin e print" warranty. W e want you t o unders tand your righ ts and o urs too ! All Ramsey kits w ill work if assemble d properly. The very [...]

SS70A • 20 SPEECH SCRAMBLER SS70A Quick Referenc e Page Guide Introduction to the SS70A .... .......... 4 Circuit Description .. ................. ....... 5 Parts list .... ................. ................ .... 7 Schematic diagram .... .................... 8 Testing the SS70A . .................... ...12 Hook-up configurations . ...............[...]