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Aircraft
Receiver
- The
Passive
Aircraft
Receiver is
basically an
amplified
"crystal
radio"
designed to
receive
nearby AM
aircraft
transmissions.
The
"passive"
design uses
no
oscillators
or other RF
circuitry
capable of
interfering
with
aircraft
communications
so it should
be fine
inside the
cabin of the
aircraft.
Nevertheless,
check the
regulations
before using
this
receiver
AM Receiver
for Aircraft
Communications
(improved)
- This
receiver is
controlled
by a
Frequency
Synthesizer
Circuit.
The receiver
is VERY
stable, low
noise-level
and easy to
build and
tune.
AM-Receiver
for Aircraft
Communication
118.250MHz
- The
aircraft
communication
in Sweden is
still
Amplitud
Modulated
(AM). The
local
airport (Axamo)
use the
frequency
118.250 MHz.
The receiver
I will
explain is a
tunable
AM-receiver
for this
frequency.
The receiver
is instead
manually
tunable with
some 100kHz
around the
118MHz. The
output from
the receiver
is a low
level output
(100-200mV)
so you must
connect it
to some kind
of
amplifier. I
will not
explain how
to build an
audio-amplifier.
Aviation
Band
Receiver
- Figure 1
shows a
schematic
diagram of
the Aviation
Receiver--a
super
heterodyne
AM
(Amplitude
Modulated)
unit built
around four
IC's: an
NE602 double
balanced
mixer (U1),
an MC1350
linear IF
amplifier
(U2), an
LM324 quad
op-amp (U3),
and an LM386
audio
amplifier
(U4). In
operation,
an antenna
that plugs
into J1
picks up the
AM signal.
That signal
is then
coupled
through C1
to a
three-section,
tuned-filter
network
consisting
of L1-L5 and
C2-C6. |
