Hi Q Test Equipment Private Limited

AM Modulation offered by us is manufactured using best available techniques and under the firm direction of experienced quality controllers.

List of Experiments:

• To study the process of Amplitude modulation and Demodulation and to calculate the depth of modulation.

Accessories:

• User Manual-1
• patch chord set -1

Features:

• Onboard modulation & demodulation circuits
• Wein bridge oscillator version modulation signal generator
• On board carrier generator (synchronized)
• 2 selectable modulation signal frequencies
• Onboard 2nd and 4th order butter worth low pass filter & amplifier
• Built in DC power supply

Introduction:

          Muting or Quieting the receiver whenever the input signal level decreases below a predetermined level is known as Squelch. In the circuit ‘Q2 is a DC amplifier drawing supply current whenever input signal falls below reference level and this leads to drive AF amplifier ‘Q1’ into cut off. When input signal increased above reference level, the AGC pulse developed from output signal drives ‘Q2’ into cut off direction and ‘Q1’ turning into active region and amplified signal is present.

List of Experiments:

• To study and design the Phase Locked Loop using the IC 565 and to obtain the free running frequency, Lock frequency and capture frequency.
• To study frequency multiplier using PLL.

Accessories:

• User Manual -1
• Patch Chord set - 1

List of Experiments:

• To study the process of frequency modulation and demodulation and to calculate the depth of the modulation.

Accessories:

• User Manual-1
• Patch chord set-1

List of Experiments:

• To study the process of Single Sideband Modulator and Demodulator.

Accessories:

• User Manual - 1
• Patch chord set - 1

• Study of frequency multiplication by synthesizer.

• User Manual -1
• Patch Chord Set -1

• Study of Pre Emphasis & DeEmphasis
• Noise produces greater effect on the higher modulating frequencies, than on the lower ones. 
• It is therefore desirable that the higher modulating frequencies
• Pre-emphasis and de-emphasis is system used for improving the signal to noise ratio of the recovered audio at the receiver.

• 1)To study the Pre-emphasis and
• De-emphasis circuits.
• 2)To calculate the gain of Pre-emphasis and De-emphasis.
• 3)To plot the corresponding frequency response curves.

• User Manual - 1
• Patch chord set - 1

Introduction:

• A balanced modulator produces AM signals with two side bands but no voltage at the carrier frequency. A differential amplifier is used to perform this function.
• Output of this modulator is DSB – SC signal. This DSB – SC signal along with RF signal is applied to the synchronous detector. In this stage amplitude variations of RF signal are identified synchronizing DSB and RF signals and the envelope of AM signal is produced.

• To Study the Characteristics of Mixer Circuit.

• User manual -1
• Patch chord set -1

List of Experiments:

• Study of AGC Characteristics of amplifier.

Accessories:

• User manual -1
• Patch chord set -1

List of Experiments:

• Study of Detector.

Accessories:

• User manual -1
• Patch chord set -1

• To study the process of balanced modulation and demodulation.
• To observe that the output is a double side band suppressed carrier signal.
• _{An IC TL072 is used to generate a sine wave which is used to drive the circuit. The sine wave is used as the modulating signal whose frequency can be varied upto 2 KHz and whose amplitude can be varied by means of a pot.}
• The oscillator is used to generate a sine wave which is used as a carrier signal whose frequency is kept constant at 100 KHz.

• In the circuit the carrier signal is supplied to pin  4 and the modulating signal input is fed to the pin 9 of IC 1495 . The suppressed carrier output is taken from terminal 14.

• The same circuit can be used as a demodulator and the output is taken from pin 2 which is then given as the input to LOW PASS FILTER and whose output is amplified in an amplifier. 

• User manual - 1
• Patch chord set -1

Frequency Division Multiplexing is a process wherein modulated signals of allotted carrier slots are simultaneously transmitter through channel or cable and during demultiplexing; these signals are separated by band pass filter or by coherent demodulation at the receiver. Thus many number of channel signals can be transmitted simultaneously and demodulated as the receiver. In practice 12 such modulated channel form a group. For the sake of convenience 3 such channels provided here for study purpose.

List of Experiments:

• Study of phase difference between two clock pulses.
• Measure phase difference from the D.C output pulse level of detector.

• User Manual -1,
• Patch Chord Set -1.