Ten-Tec SSB-CW-AM, Инструкция по эксплуатации

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FILTER-ACTIVE
FILTER-CERAMIC
FILTER-CRYSTAL
Filters are used in DC, Audio and RF
FILTER-HI-PASS circuits. Understanding them is essential
FILTER-LOW-PASS electronics know-how.
FILTER-BANDPASS
FILTER-PASSIVE
FREQUENCY SYNTHESIS
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frequencies are a crystal oscillator or the L-C oscillator where the frequency is
determined by coil (L) and capacitor ©. However we can process the output of an
L-C oscillator through digital circuitry to simulate many different, precise crystal-like
frequencies, using only one crystal as a reference standard. See also PLL, PHASE
DETECTOR, VCO.
GROUND PLANE
Ź
ALL sections of a circuit board which are mechanically or
electrically connected to DC and RF ground. In the 1254 receiver design, almost ALL
of the top or upper side (component side) of the board is a groundplane. The term is
also used in antenna design: if your antenna has a vertical radiating element, plus
four (or more) horizontal elements connected to RF ground, the horizontal elements
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HIGH
Ź
In solid-state logic circuitry, to say a given device pin or circuit point is at a
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to the opposite state (LOW) or back again for some specific purpose is a fundamental
capability of the circuit.
IF (Intermediate Frequency) Ź In any superheterodyne receiver, and IF is the
frequency resulting from mixing an incoming signal with the signal from an LO within
the receiver. The Model 1254 has two IF's: 45 MHz and 455 kHz. Se also LO,
Mixer, Superhet.
JUMPER
Ź
Any wire soldered to interconnect points in a circuit not otherwise
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are short jumper wires in a resistor body painted with one black band.
L-C
Ź
A tuned circuit made of inductor (L) and capacitor ©.
LOCAL OSCILLATOR (LO)
Ź
An oscillator in a superhet receiver whose output is
mixed with another signal such as antenna input. See SUPERHET.
LOCK Ź The condition in a phase-locked-loop (PLL) in which all sections are
working together as intended and designed.
LOOP FILTER Ź (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
1254
±
Reference - 25