21
v .
INDICATOR
(eg PM 2.03)
,
,
'
.
,
'
� -
+
+
RF
OUT
MA 8296
Fig.
14.
Al ternately damping and adjusting the primary and secondary circuits
2. 3.3.2.2. R F and oscillator circuits
- Connect the indicator according to F ig, 14
- Connect the h.f. generator to the f.m. aerial input via impedance transformer
PM
9537
- Set the volume control of the receiver to minimum
- Set the receiver to f.m. ( V H F)
-
Adjust the pointer to the mark on the dial given in the
tuning
table
of the
receiver-documentation
- Set the receiver and the h.f. generator to the frequency ind icated in the tuning table of the receiver
-
Adjust the cores ot the h.f. and oscillator circuits to m aximum deflection
of the
indicator
in
the
sequence
mentioned in the tuning table.
2.3.3.3. Checking and adjusting at TV sets
2. 3.3.3.1. General
The i.f. a mplifier of a TV'set must meet several requirements:
- the
band-pass curve should have
a
correcting effect on the
frequency
response curve
of
the transmitter
signal,
in
which the low frequencies have the advantage with respect to
the
high frequencies.
This i mplies, a mong others', that the carrier of the picture signal has to be attenuated by a factor 2 ( Fig. 15).
-
The sound carrier must be attenuated too : in
inter-carrier receivers
12 to 20 times (f2), in separated
carrier
receivers 200 times (f3).
-
finally, complete suppression must take place of the
sound
carrier in the adjacent higher channel (f4) and of
the i mage carrier in the adjacent lower channel (f5).
f1
f5 f3
ft.
MA8212
Fig.
15.
Idealized band-pass curve of the i. f. amplifier of a TV set
Af
Af1
=-
2
Af
Af2 = -
--
--
12+20
Af
Af3=
--
200
Af
Af4
=
Af5 = --
800
Содержание PM5324
Страница 1: ...HF Generator 100kHz 110MHz PM5324 9452 053 240 1 9499 450 05511 730801 1 01 ...
Страница 15: ...14 Fig 4 Front view Fig 5 Rear view ...
Страница 43: ...Fig 33 Front view with item numbers Fig 34 Bottom view ...
Страница 44: ...44 Fig 35 Top view Fig 36 Left side view ...
Страница 45: ...45 0 0 0 0 1 ji I I MAB225 Fig 37 Scale dri ve n ...
