Products
DAC Trainer
The communication hardware trainer kits are designed to provide a deep insight into the principles, basic and advanced, of analog and digital communication. Comprehensive, concept based and interactive our trainer kits are an indispensable tool for the student as well as for the multi-craft training needs of instrumentation, electronics and communications industries.
Analog Communication
Analog Communication Trainer Kits
- Analog Signal Sampling and Reconstruction.
- Pulse Amplitude Modulation/Demodulation
- Pulse Position Modulation/Demodulation
- Pulse Width Modulation/Demodulation
- TDM Pulse Amplitude Modulation/Demodulation.
Digital Communication
Digital Communication Trainer Kits
The kits are manufactured with PCBs of SMOBC finish and are glass epoxy coated. The IC's are mounted on machined IC based for ease of servicing and replacement. The passive components are of 1% tolerance. The entire kit is mounted in a closed fiber glass box for safe keep. The block diagram is visible to the users for ease of understanding. Test points are provided for each functional block.
All the kits have noise input facility for introducing noise in the demodulator/decoder section. Using TETCOS noise generator noise can be introduced. The bit errors generated due to noise introduction can be measured using the Bit Error Measurement unit. Together with the noise generator and bit error measurement unit signal to noise ratio Vs Probability error curves can be plotted.
The user friendly manual shows step by step procedure of experiments. Waveforms for each test point/experiment is also given in the manual. IC numbers and their positions are shown in the diagram for servicing/replacement.
Source Coding
- Pulse code modulation
Source Coding Scheme PCM Encoder and Decoder
Experiments:
- To measure the various control signals.
- Data rate
- 8 bit digital data of NRZ (Non Return to Zero) pattern
- Word pulse / Convert pulse
- To observe the sampled signals with respect to convert pulse
- FSC and data slot
- FSC pulse and sampled input analog signal
- PCM signal output.
- To observe the characteristics of two channel multiplexing
- Sampled output
- PCM output
- To measure the characteristics of different signals involved in the decoder block of PCM
- Clock signal
- Frame pulse signals
- DAC output
- Final output
Technical Specification:
| ENCODER |
| AUDIO SIGNALS GENERATED | 1 KHz |
| AMPLITUDE | 2 VPP |
| DISTORTION | 1% |
| FREQUENCY | 1 KHz |
| DC SIGNAL | (+/-)5v |
| DATA RATE | 8/16/32/64 KHz and Ext Clock |
| WORD LENGTH | 8 bits |
| SAMPLING RATE | 8000/4000/2000/1000 samples/seconds |
| TOTAL NUMBER OF WORDS TRANSMITTED | 128 words |
| FSC SLOT | 2 words |
| DATA SLOT | 126 words |
| CHANNEL | two |
| ADC |
| POWER SUPPLY | 5VDC |
| RESOLUTION | 8 bits/40 mV |
| UNADJUSTABLE ERROR | (+/-)1/2LSB and (+/-)1LSB |
| CONVERSION TIME | 100 ms |
| Decoder |
| BCD TO DECIMAL CONVERTER | 4028 |
...close Pulse code modulation
- Differential Pulse code modulation(DPCM)
Experiments:
- Employing a particular coding scheme distortion (Fidelity) can be measured with different input wave shapes.
- Selection of multiplier coefficient of present and previous samples with respect to the slope of the input signal
- Observe the DPCM output waveform for a given input and its reconstruction at decoder.
Technical Specification:
| DATA RATE | 64/ 32/ 16/ 8 Kbps |
| WORD LENGTH | 8 bits |
| INPUT | 2V pp Sine/Square/Triangular |
| INPUT FREQUENCY | 0-2.5 KHz (Max) |
| SAMPLING RATE | 8/4/2 K per Sec |
| ADC WORD LENGTH | 8 bits |
| RANGE | +/ -5 V |
| MODE OF OPERATION | fast (optional) and slow |
| DC | 0 to +/ -5V |
| DAC WORD LENGTH | 8 bits |
| RANGE | +/-5V |
| NO. OF TEST POINTS | 27 |
...close Differential Pulse code modulation
- Delta modulation / Adaptive Delta Modulation
Experiments:
- To monitor and measure the various control signals.
- Data rate / Selected clock
- Analog signals - Sine/Square/Triangle
- To monitor the characteristics of DM/ADM encoder block
- Selected clock
- Sampled input signal
- Up / Down counter
- DAC output
- DM/ADM output
- To measure the characteristics of DAC output with different step sizes
- Selected clock
- DAC output
- To study the slope overload and Quantization error
- Clock signal
- Frame pulse signals
- DAC output
- Final output
- Observation of automatic step size variation in ADM.
- To measure the characteristics of DM/ADM decoder and sampling theorem verification by varying the frequency of input and clock frequency.
Technical Specification:
| ENCODER |
| SINE / TRIANGULAR / SQUARE INPUT SIGNAL |
| AMPLITUDE | 2 VPP |
| FREQUENCY | 0.5 - 4KHz |
| DC SIGNAL | (+/-)5v |
| DATA RATE | 8/16/32/64 KHz and Ext Clock |
| WORD LENGTH | 8 bits |
| STEP | Variable by changing DIP switch settings |
| UP/DOWN COUNTER | 4029 |
| DAC |
| WORD LENGTH | 8 bits |
| RESOLUTION | 40 mV |
| CONVERSION TIME | 100 - 116ms |
| OPERATING VOLTAGE | 5VDC |
| OPERATING CURRENT | < 10 mamps |
Features:
- All IC's are mounted on machined IC base
- PCB's are SMOBC finished with glass epoxy coating
- Multi color printed block diagram is given on the top of the kit
- Testing point at the end of each functional block
- 28 or 256 data pattern combinations available through dip switches
- The trainer kit is enclosed in fiber glass box for safe keep.
...close Delta modulation / Adaptive Delta Modulation
- Line Codes
Experiments:
- To find the spectrum of different line coding schemes available in the module.
- To observe the different wave forms of converted NRZ (L) to other coded forms for all the line codes
- To observe the waveforms
Technical Specification:
| TRANSMITTER |
| DATA RATE | 64/ 32Kbps |
| WORD LENGTH | 8 bits |
| DATA PATTERN | User Programmable |
| OUTPUT CODES | NRZ (L), NRZ (S), NRZ (M), BI (L), BI (S), BI (M), RZ, AMI |
| CODE SELECTION | by dip switch |
| RECEIVER |
| DATA RATE | 64/ 32Kbps |
| INPUT CODES | NRZ (L), NRZ (S), NRZ (M), BI (L), BI (S), BI (M), RZ, AMI |
| OUTPUT CODE | NRZ (L) |
| INPUT SELECTION | by dip switch |
| NO. OF TEST POINTS | 38 |
...close Line Codes
- Modulation
- Amplitude Shift Keying / Frequency Shift Keying
Experiments:
- To measure the parameters of various control signals.
- Word pulse with reference to clock
- 8 bit digital data of NRZ (Non Return to Zero) pattern
- Data rate/select clock rate (300/600bps) to word pulse
- To measure the different signals involved in ASK generation
- Mark Frequency (10 KHz).
- ASK modulated output
- To measure the characteristics of ASK demodulator
- LPF and BPF output.
- Envelope detector output.
- ASK demodulated output
- To measure the different signals involved in FSK generation
- 8bit digital data of NRZ pattern
- Mark frequency (10 KHz).
- Space frequency (5 KHz).
- FSK modulated output
- To measure the characteristics of FSK demodulator
- LPF and BPF outputs.
- Envelope detector output.
- FSK demodulated output
- Frequency Separation study.
Technical Specification:
| Modulator |
| CARRIER SINEWAVE GENERATOR | 5 KHz, 10KHz |
| AMPLITUDE | 2 VPP |
| DISTORTION | 0.5% |
| MARK FREQUENCY | 10 KHz |
| SPACE FREQUENCY | 5 KHz |
| MUX | 2:1 |
| SPACE FREQUENCY | 5 KHz |
| DIGITAL DATA | 8 bits |
| DATA PATTERN | NRZ |
| WORD PULSE LENGTH | 8 bits |
| DATA RATE | 300 / 600 bps |
| Demodulator |
| BAND PASS FILTERS | 5 KHz, 10KHz |
| ENVELOPE DETECTOR | Two |
| LATCH | One |
FEATURES:
- All IC's are mounted on machined IC base.
- PCB's are SMOBC finished with glass epoxy coating.
- Multi color printed block diagram is given on the top of the kit.
- Testing point at the end of each functional block.
- 28 or 256 data pattern combinations available through dip switches.
- The trainer kit is enclosed in fiber glass box for safe keep
...close Amplitude Shift Keying / Frequency Shift Keying
- Phase Shift Keying
Experiments:
- To measure various control signals involved in code conversion
- Selected clock/data rate
- 8bit digital data of NRZ pattern - 256 combinations of data.
- Word pulse
- To measure the different signals involved in PSK generation
- Sinusoidal signal
- Amplitude 2VPP
- Frequency 10KHz
- Phase 0° and 180°.
- PSK Modulated output
- To measure the characteristics of PSK demodulator block
- Multiplier and LPF output.
- PSK demodulated output
- Final demodulated output
Technical Specification:
| Modulator |
| CARRIER SINEWAVE GENERATOR | 10KHz |
| AMPLITUDE | 2 VPP |
| DISTORTION | 0.5% |
| FREQUENCY | 10 KHz |
| Phase | 0° and 180° |
| MUX | 2:1 |
| DIGITAL DATA | Programmable 8 bits |
| DATA PATTERN | NRZ (L) |
| WORD PULSE LENGTH | 8 bits (1 byte) |
| DATA RATE | 300 / 600 bps |
| Demodulator |
| BAND PASS FILTERS | 10KHz |
| MULTIPLIER | One |
FEATURES:
- All IC's are mounted on machined IC base.
- PCB's are SMOBC finished with glass epoxy coating.
- Multi color printed block diagram is given on the top of the kit.
- Testing point at the end of each functional block.
- 28 or 256 data pattern combinations available through dip switches.
- The trainer kit is enclosed in fiber glass box for safe keep
...close Phase Shift Keying
- Differential Phase Shift Keying
Phase-shift keying (PSK) is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave).
Any digital modulation scheme uses a finite number of distinct signals to represent digital data. In the case of PSK, a finite number of phases are used. Each of these phases is assigned a unique pattern of binary bits. Usually, each phase encodes an equal number of bits. Each pattern of bits forms the symbol that is represented by the particular phase. The demodulator, which is designed specifically for the symbol-set used by the modulator, determines the phase of the received signal and maps it back to the symbol it represents, thus recovering the original data. This requires the receiver to be able to compare the phase of the received signal to a reference signal — such a system is termed coherent.
Alternatively, instead of using the bit patterns to set the phase of the wave, it can instead be used to change it by a specified amount. The demodulator then determines the changes in the phase of the received signal rather than the phase itself. Since this scheme depends on the difference between successive phases, it is termed differential phase-shift keying (DPSK).
Experiments:
- To measure the parameters of various control signals.
- Selected clock /data rate.
- 8bit digital data of NRZ pattern - 256 combinations of data
- Word pulse.
- To measure the different signals involved in ASK generation and to measure the different signals involved in DPSK generation
- Sinusoidal signal
- Amplitude 2V pp
- Frequency 10KHz
- Phase 0° and 180°
- DPSK modulated output
- To measure the characteristics of DPSK demodulator block
- Multiplier and LPF output
- DPSK demodulated output
- Final demodulated output
Technical Specification:
| Modulator |
| CARRIER SINEWAVE GENERATOR | 10KHz |
| AMPLITUDE | 2 V pp |
| DISTORTION | 0.5% |
| FREQUENCY | 10 KHz |
| MUX | 2:1 |
| SPACE FREQUENCY | 5 KHz |
| DIGITAL DATA | 8 bits |
| DATA PATTERN | NRZ |
| WORD PULSE LENGTH | 8 bits |
| DATA RATE | 300 / 600 bps |
| Demodulator |
| BAND PASS FILTERS | 10KHz |
| ENVELOPE DETECTOR | Two |
| LATCH | One |
FEATURES:
- All IC's are mounted on machined IC base.
- PCB's are SMOBC finished with glass epoxy coating.
- Multi color printed block diagram is given on the top of the kit.
- Testing point at the end of each functional block.
- 28 or 256 data pattern combinations available through dip switches.
- The trainer kit is enclosed in fiber glass box for safe keep
...close Differential Phase Shift Keying
- Quadrature Phase Shift Keying
Phase-shift keying (PSK) is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave).
Also known as quaternary or quadriphase PSK or 4-PSK, QPSK is one of the PSK techniques which uses four points on the constellation diagram, equispaced around a circle. With four phases, QPSK can encode two bits per symbol, shown in the diagram with Gray coding to minimize the BER — twice the rate of BPSK. Analysis shows that this may be used either to double the data rate compared to a BPSK system while maintaining the bandwidth of the signal or to maintain the data-rate of BPSK but halve the bandwidth needed.
Experiments:
- To measure the parameters of various control signals.
- Selected clock /data rate.
- 8-bit NRZ (L) digital data - 256 combinations of data
- Word pulse.
- To measure the different signals involved in QPSK generation
- Sinusoidal signal
- Amplitude 2V pp
- Frequency 10KHz
- Phase 0°, 90°, 180° and 270°
- In phase and Quadrature components
- Output of BPSK modulation because eventually QPSK modulator output is two BPSK modulators combined in parallel.
- Finally QPSK modulated output.
- To measure the different signals involved in QPSK demodulation
- Carrier signal recovery at multipliers
- LPF and Comparator output
- Data recovered at Bit combiner
Technical Specification:
| Modulator |
| CARRIER SINEWAVE GENERATOR | 10KHz |
| AMPLITUDE | 2 V pp |
| DISTORTION | 0.5% |
| CARRIER FREQUENCY | 10 KHz |
| DIGITAL DATA | 8 bits |
| DATA PATTERN | NRZ (l) |
| WORD PULSE LENGTH | 8 bits |
| DATA RATE | 300 / 600 bps |
| Demodulator |
| BAND PASS FILTERS | 10KHz |
| ENVELOPE DETECTOR | |
| LATCH | |
FEATURES:
- All IC's are mounted on machined IC base.
- PCB's are SMOBC finished with glass epoxy coating.
- Multi color printed block diagram is given on the top of the kit.
- Testing point at the end of each functional block.
- 28 or 256 data pattern combinations available through dip switches.
- The trainer kit is enclosed in fiber glass box for safe keep
...close Quadrature Phase Shift Keying
- Noise Generator
Experiments:
The bit error measurement unit together with the noise generator can be used as a powerful tool for simulation and experimentation. The signal to noise ratio v/s probability of error curve can be plotted. The noise generator has facility for the noise introduction to the appropriate digital communication trainer kit for study under simulated noise conditions.
Technical Specification:
| PN SEQUENCE LENGTH
| 220 - 1 |
| NOISE AMPLITUDE | Variable by front panel pot |
| BIT RATE | Variable |
| NOISE | Gaussion Noise |
| FREQUENCY SEQUENCE LENGTH | 2KHz - 16 KHz |
| SIGNAL | Voltage wave |
| AMPLITUDE | Variable 0 - 5v from front panel |
FEATURES:
- The whole unit is enclosed in powder coated steel enclosure
...close Noise Generator
- Bit Error Measurement
The bit error measurement unit together with the noise generator can be used as a powerful tool for simulation and experimentation. The signal to noise ratio v/s probability of error curve can be plotted.
Technical Specification:
| DISPLAY | Seven Segment 4 digit |
| TIME INTERVAL | Selected from Front Panel Thumb Wheel Switch (1.6,16, 160 sec.) |
| POWER SUPPLY | Built in |
FEATURES:
- The bit error unit displays number of bit errors during the time which is set by thumb wheel switch.
- The whole unit is enclosed in powder coated steel enclosure
...close Bit Error Measurement
- Spread Spectrum
- Direct Sequence Spread Spectrum
Experiments:
- To find Processing Gain (using Spread Analyzer)
- To find the BER curves under different noise input conditions
- To find Jamming margin using narrow band noise source
Technical Specification:
| CRYSTAL OSCILLATOR | 6.144 MHz |
| DATA RATE | 64 / 32 kbps |
| WORD LENGTH | 8 bits |
| FRAME LENGTH | 16 words |
| FRAME SYNC CODE | 3 words |
| DATA SLOT | 13 words |
| PN SEQUENCE LENGTH | 23 - 1 |
| PN SEQUENCE CHIP RATE | 256 / 128 kbps |
FEATURES:
- All IC's are mounted on machined IC base.
- PCB's are SMOBC finished with glass epoxy coating.
- Multi color printed block diagram is given on the top of the kit.
- Testing point at the end of each functional block.
- 28 or 256 data pattern combinations available through dip switches.
- The trainer kit is enclosed in fiber glass box for safe keep
...close Direct Sequence Spread Spectrum
- Frequency Hopping Spread Spectrum
Experiments:
- To Find Processing Gain (Using Spectrum Analyzer).
- To Find BER Curves under different noise input conditions
- To Find Jamming margins using narrow band noise source.
Technical Specification:
| DATA RATE | 1/ 2 Kbps |
| WORD LENGTH | 8 bits |
| FRAME LENGTH | 8 words |
| FRAME SYNC CODE | 3 words |
| DATA SLOT | 5 words |
| PN SEQUENCE LENGTH | 2^3-1 |
| PN SEQ CHIP RATE | 4/ 8Kbps |
| HOPPING FREQUENCY | 16/ 32/ 64/ 128 Kbps |
| NO. OF TEST POINTS | 41 |
...close Frequency Hopping Spread Spectrum
Testimonial
"Tetcos digital and analog communication trainers have been a cost effective tool for teaching complex concepts in communication theory. They have allowed me to give visual presentations of communication signals using standard test equipment at low frequencies that show each stage of signal processing. I highly recommend Tetcos trainers as a valuable training tool."
Chris Akelian
Engineering and Technology Division Chair
Cuesta College
1504 Colusa Ave.
San Luis Obispo, CA 93403-8106
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