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Now you can use touch-tones to control virtually anything via radio, 
phone line or even tape.  The kit is backed up by powerful 20mA 
output lines that can be set up to control nearly anything that you can 
think of.  And, you are backed up by over 25 years of excellence from 
the world’s best kit supplier. 

Turning on and off lights, radio and TVs in your home are just 
some of the almost infinite possibilities! 

 

A state-of-the-art “central office quality” decoder makes the 
Touch Tone Decoder extremely reliable and accurate. 

 

It’s powerful 20mA driving capability can power relays, digital 
devices, LED’s and more! 

 

It even decodes the four additional A, B, C and D tones! 

 

You build it in one evening.  Why spend big money when you 
can say “I built it myself!” for a fraction of the cost. 

 

Clear concise instructions guide you to a finished kit...and then 
offer hints and tips on how to hook it up and use it.  Ramsey is 
right there with you all of the way! 

 

Become one of many satisfied Ramsey customers and be one 
of the 

World’s Best Kit Builders!

 

 

TOUCH TONE 

DECODER 

Ramsey Electronics Model No.                TT7 

Summary of Contents for TT7

Page 1: ...ce quality decoder makes the Touch Tone Decoder extremely reliable and accurate It s powerful 20mA driving capability can power relays digital devices LED s and more It even decodes the four additiona...

Page 2: ...eter RAMSEY AMATEUR RADIO KITS DDF1 Doppler Direction Finder HR Series HF All Mode Receivers QRP Series HF CW Transmitters CW7 CW Keyer CPO3 Code Practice Oscillator QRP Power Amplifiers RAMSEY MINI K...

Page 3: ...OF CONTENTS Introduction to the TT7 4 How it works 4 Parts list 5 TT7 Assembly instructions 6 Setup and testing 8 Troubleshooting 9 Ideas and uses for the TT7 10 Touch tone frequencies 13 Schematic di...

Page 4: ...your kit to stay small enough to fit in some radios yet useful enough for any decoder need Another chip included with your kit is the 74LS154 demultiplexer This chip decodes the output of the decoder...

Page 5: ...we will begin building our kit There are just a few more things to know before we put the first components in For each part our word Install always means these steps 1 Pick the correct value to start...

Page 6: ...der bridges or cold solder joints 2 Install R2 47K ohm resistor yellow violet orange R2 must be mounted standing up To do this first place one lead all of the way into the hole marked with a circle Ne...

Page 7: ...sistor brown black orange Mount it standing 11 Install Q1 a 2N3904 NPN transistor Make sure that the part is mounted with its flat side facing R1 12 Install U2 the 74LS154 demultiplexer chip First ide...

Page 8: ...or answering machine please contact the manufacturer for additional information on a particular product 1 Hook the 5 volt power supply to your TT7 To do this run a wire from the side of your supply to...

Page 9: ...is that there are no solder bridges Don t be afraid to go back and reheat connections to be sure that they are not cold solder joints Now check to see if you have some sort of short in the circuit su...

Page 10: ...prank caller or your best friend were to call and try to operate your TT7 you are at least aware that this has happened because all of the tones are recorded on your machine In order to hook up LED s...

Page 11: ...is no difference in the accuracy of the kit some people may appreciate this feature To hook your TT7 up to your TS1 you need to make a few simple modifications First of all there are two separate lat...

Page 12: ...of four high frequencies To determine what frequencies make up each digit first find the digit that you want on the chart We ll pick 6 for an example Simply reference it to the frequency above it and...

Page 13: ...TT7 13...

Page 14: ...TT7 14 TT7 Parts Layout Diagram...

Page 15: ...be assured that the 1K ohm resistors are actually the missing 10 K parts Hum m m I guess the red band really does look orange Ramsey Electronics project kits are packed with pride in the USA If you be...

Page 16: ...3 Parts Layout diagram 14 Price 5 00 Ramsey Publication No MTT7 Assembly and Instruction manual for RAMSEY MODEL NO TT7 TOUCH TONE DECODER REQUIRED TOOLS Soldering Iron Ramsey WLC100 Thin Rosin Core S...

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