a typical squelch circuit cut off

an audio amplifier when carrier is absent    

In horizontal-dipole antenna, the polarization is

In horizontal-dipole antenna, the polarization is



in the horizontal direction

the transistor with the lowest noise figure in the microwave region is a

the transistor with the lowest noise figure in the microwave region is a

 MESFET

Normally, a linear class B RF power amplifier operates with a bias approximately equal to

Normally, a linear class B RF power amplifier operates with a bias approximately equal to


projected cut-off

Combination of modulator, channel, and detector.

Combination of modulator, channel, and detector.


 Discrete channel

A method of expressing the amplitudes of complex non-periodic signals such as speech.

 A method of expressing the amplitudes of complex non-periodic signals such as speech.


" Volume  "

The reverberation time of a 184.2 cubic meters broadcast studio is 0.84 sec. Find the absorption effect of the materials used in metric sabines.

 The reverberation time of a 184.2 cubic meters broadcast studio is 0.84 sec. Find the absorption effect of the materials used in metric sabines.


"  35.3   "


formula:
 T60 = 0.161xV
STxAave

V-- volume unit m^3

ST-- second unit s

read more tips:
please see the link: http://www.soundonsound.com/sos/sep98/articles/acoustic_3.html

A diagram which shows the relationship between RF signal phase and maximum bunching of the electron beam in velocity-modulated devices.

 A diagram which shows the relationship between RF signal phase and maximum bunching of the electron beam in velocity-modulated devices.



" Applegate Diagram  "

Single sideband full carrier emission type.

Single sideband full carrier emission type.

 H3E

What is the reference tone level for dBrn?

What is the reference tone level for dBrn?

 -90 dBm

Actual height of antenna should be at least, " quarter wavelength "

Actual height of antenna should be at least, " quarter wavelength "

Psophometer , is a device that measures the internal open circuit voltage of an equivalent noise generator having an impedance of 600 ohms and delivering noise power to a 600 ohms load.

Psophometer,  is a device that measures the internal open circuit voltage of an equivalent noise generator having an impedance of 600 ohms and delivering noise power to a 600 ohms load.