Akai VS-2EGN - Page 94

SSK
4) Fig. 7-151 shows an example of the standard quality
of IF response,
An exampel of standard
IF response
Fig.
7-151
An
example
of
the
standard
quality
of
IF
response
IF response is defined by the level differences from the
peak output of waveform. During the assembly with the
IF PCB, the response waveform can be adjusted to some
degree by the core of the IFT. (The center of the wave-
form becomes incorrect.)
10-2-7 UHF CIRCUIT
The UHF circuit is basically the same as the VHF cir-
cuit except that the former employs a distributed com-
ponent
circuit
because
of
the
high
frequency.
1) Distributed component circuit
In case of these high frequencies, the coil for the tuned
circuit cannot be made as a discrete component. There-
fore, a transmission line resonant circuit is used.
@ Symbols in circuit diagram
Fig. 7-152 Distributed component circuit
cIRCUIT
1
|
|
|
ANT INO
|
|
|
|
|
|
|
|
i}
|
|
|
i
|
INPUT |
1
i
1
1
I
o_o
Orr
Service
Manual
VS-2EGN.
® In the construction as shown in Fig. 7-153, when
the length 2 is a quarter of the signal wavelength, im-
pedance Zo becomes inductive, and line performs the
same operation as a coil.
SECTIN
YZ,
SO
Z
Y
Fig. 7-153
WW
SSS
N
Fig. 7-154
2) Fig. 7-155 shows the equivalent circuit of the UHF
tuner.
}->TO CASCADE AMP
Seneeas bens
Fig. 7-155 UHF tuner equivalent circuit
91