Ramsey Electronics FX-440 Manual page 45

·· KEY, "to key• = to turn on a transmitter's carrier signal momentarily, whether by a
telegraphy code key (the root or this very common radio jargon) or by a push-to-talk switch.
L.C
=
A tuned circuit made of inductor (L) and capacitor (C).
LIMITER = The portion or an FM receiver circuit which chops off noise and AM (amplitude
11odulation). It processes the IF signal so that only FM will be detected.
LOCAL OSCILLATOR (LO)
=
An oscillator in a superhet receiver whose output is mixed
with another signal such as antenna input. See SUPERHET.
_QCK = The condition in a phased-locked-loop (PLL) in which all sections are working
ogether as intended and designed.
LOOP-FIL TEA
=
(See PLL). The output of a PLL phase detector is in the form of pulses.
The frequency of those pulses depends on the reference frequency. The loop filter smooths
iut these pulses into a clean DC control voltage for the VCO. (See: VCO) ....
LOW
=
indicates a logic level at or near zero volts.
MATRIX = A methodical criss-crossing of many connections.
llC- = Prefix for parts made by Motorola, Inc.
MIXER = A circuit section which gets
two
or more inputs and delivers a single output. The
output is equal to the sum of the input frequencies and also to the difference between them.
mDULATION = See also: CW, FM. "Modulation" is simply the process ol imposing
.ariations on a steady RF signal from an audio source such as voice, music or data (see:
AFSK).
~UTE
= to turn off, to render silent. (See also SQUELCH)
. l = can be any number to solve in a classroom problem, but "N" is THE magic number
(decimal) to understand in FX- binary frequency- programming. N = the frequency in KHz
divided by 5 KHz.
IBFM
=
"Narrow-Band FM."
NE- = prefix to transistors or IC's made by Signetics, Inc.
FFSET = The distance in KHz or MHz or the transmitted signal from the primary or
iceived signal. The "TX Offset• may be higher or lower, depending on the repeater setup
. · other application.
OP-AMP
=
"Operational Amplifier,• a high performance linear amplifier with an Inverting
put, a Non- inverting Input and one Output.
RIENT, orientation = Yes, the Orient is Marco Polo's Far East where they build many FM
radios and where we buy many common parts. When we ask you to "orient" a kit part one
way or the other, we're just asking you to get it RIGHT - per all the •orientation"
·· JStrations that we provide.
11.CKET = Rapid transmission of intelligible computer-generated data in groups or burs!S
or a fixed length called "packets.•
~'-iASE
DETECTOR = In a frequency synthesizer, the phase detector compares the signal
>m a reference oscillator to the signal from a programmable counter and sends a
1rrected control voltage to the L.C section or a VCO. Thus, it can be considered a phase
"corrector." See also: VCO, PLL, VARACTOR.
~'ATED-THROUGH
= Refers to a style of PC-board manufacturing in which traces on both
Jes of the board are interconnected by a coating or solder around the inside of each hole.
POLARITY
=
Refers to the •
+ •
and ·-· sides of batteries, power supplies, power cables,
electrolytic capacitors, etc.
X-440
Ref. 43