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CB receiver
source:
Kyriakos Kontakos
TECHNICAL CHARACTERISTICS:
Tendency of catering: + 12V DC
Frequency of reception at AM: ~27MHz


Materially:
The resistances are 1/4W.
R1, R3, R5 |
100W |
R2 |
56KW |
R4 |
39KW |
R6 |
560W |
R7, R11 |
6,8KW |
R8 |
220W |
R9 |
2,2KW |
R10 |
5,6KW |
R12 |
10KW logarithmic
pontesiometer |
R13 |
1KW |
R14 |
10W |
C1 |
150pF ceramic |
C2 |
39pF ceramic |
C3, C5 |
12pF ceramic |
C4 |
56pF ceramic |
C6, C7, C8, C9,
C10, C11, C16, C21 |
47nF ceramic |
C12, C19 |
47mF/16V
electrolytic |
C13, C14 |
10nF ceramic |
C15 |
100nF polyester |
C17 |
10mF/16V
electrolytic |
C18 |
2,2mF/16V
electrolytic |
C20 |
470mF/16V
electrolytic |
D1 |
AA119, AA117 (germanium
diode) |
Q1, Q2 |
BF241
(amplifiers of intermediary frequency) |
U1 |
SO42P (mixed and
local oscillator) |
U2 |
LM386 (amplifier
A.F.) |
Y1, Y2 |
Crystals hails.
(You can you put the so much, those who also channels that
you want you touch). See here. |
MF1 |
Medium frequency
455KHz, core yellow.
* |
MF2 |
Medium frequency
455KHz, core white.
* |
MF3 |
Medium frequency
455KHz, core black.
* |
L1, L2 |
Wires of coper
(smaltwme'na) with diameter 0,4mm wrapped in plastic support
of diameter 6-7mm of perjstrofjkoy' core. For the L1 you
wrap 13 coils. For the L2 you wrap 4 coils. |
LS1 |
Loudspeaker
8W/1W. |
ANT1 |
Aerial for CB
(For the trials is enough a piece wire of few metres). |
S1 |
Switch of choice
of channel. It has so much places, those who also the
channels that you want to touch. |
* Intermediary frequencies mf1-3 you can him
find in a old radio AM.
Regulations:
For the regulation needs a
transmitter or generator in mpa'nta the CB, that is to say in
the region 27MHz. If you have a certain friend with CB, you
convince you to help.
-
Connect a piece of cable around
in the one metre in the place of aerial.
-
Be supplied the receptor with +
12V and turn in half the potentiometer of regulation of sound
(R12).
-
Turn on the generator or the
transmitter CB and you emit in distance of 10 metres roughly
from the receptor, in the channel that receives the receptor..
-
From the loudspeaker it will be
supposed it begins to be heard what you emit and if it does
not have big force, you turn the core of inductor L1/L2 until
you have a increase of intensity. After this you can continue
with the various medium frequencies beginning from black (MF3)
until you have the biggest intensity. If it is heard
mjkrofwnjsmo's, you lower little the intensity of loudspeaker
or you remove the transmitter from the receptor.
Modification:
If you cannot find krysta'lloys you
can make the modification that shows the form. That is to say,
instead of crystal you in joint action put respectively
coordinated circuits with LC each one in different channel.
L |
Same with the
L1. |
C |
4 - 40pF trimmer |
Notes:
The receptor this can combine itself with the
transmitter CB in order to you manufacture a complete station
CB.
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