SOME HELP
WITH TERMS & ABBREVIATIONS
The following are intended to be helpful descriptions, not formal
definitions. We try to use plain language as much as possible in
this manual, avoiding unnecessary jargon.
Active Antenna
Ź
A combination of a very short antenna, such as a telescoping
whip, and electronic circuitry designed to correct shortened antenna impedance
mismatch and provide amplification or gain.
ALIGN, Alignment
Ź
The process of adjusting coils or trimmers (either capacitors or
resistors) in an RF electronics circuit for best performance. This process is done
either by ear or in reference t0 test instruments. The Model 1254 alignment
procedure is as simple as it can get for a circuit design of this level of sophistication.
AM ("Amplitude Modulation")
Ź
Changing the transmitter output power level in
exact step with speech or sound variations. In contrast, FM (frequency modulation)
varies the transmit frequency in exact step with speech or sound variations. Also
see SSB.
BFO
Ź
"Beat Frequency Oscillator." See CLARIFIER below.
BOARD
Ź
Generally refers to "PC-board" or "printed circuit board."
BUFFER
Ź
An electronic circuit stage, a sort of "referee" that tells its input and
output not to mess with each other. Think about such a task! It may also provide
amplified output of the incoming signal.
CARRIER
Ź
Transmitted RF signal that is NOT "modulated." It is a heard as a
steady tone in SSB-CW mode or as a sort of hum in AM mode.
CCW
Ź
see CW below.
CLARIFIER
Ź
A control for minor frequency adjustment of an IF oscillator, thereby
emulating a "Beat Frequency Oscillator" (BFO) in traditional receiver design.
"CW"
Ź
TWO common meanings in electronics: "Continuous Wave" for the
communicating of morse code signals, or "Clockwise" to designate a point on a
variable control. "CCW" therefore means "counterclockwise."
DIP
Ź
"Dual Inline Package," referring to IC's and their sockets or any other
component ("DIP Switch," etc.). The "line" refers to rows of PC-board or perfboard
holes that are 0.1" apart. "Dual" means two rows. Therefore "SIP" would mean a
SINGLE row device.
1254 - Reference
±
24
Содержание SSB-CW-AM
Страница 25: ...1254 Assembly 4...
Страница 34: ...Phase 2 0 Assembly begins on page 14 1254 Assembly 13 This space is for your notes...
Страница 35: ...1254 Assembly 14 Phase 2 0 Schematic Diagram Details...
Страница 46: ...This space is for your notes Phase 3 0 Assembly begins on page 26 1254 Assembly 25...
Страница 47: ...1254 Assembly 26 Phase 3 0 Schematic Details...
Страница 57: ...1254 Assembly 36 Phase 4 0 Schematic Details...
Страница 68: ...1254 Assembly 47 This space is for your notes...
Страница 69: ...Phase 5 0 Schematic Details 1254 Assembly 48...
Страница 77: ...Phase 6 0 Schematic Details 1254 Assembly 56...
Страница 93: ...1254 Assembly 72 This space is for your notes...
Страница 101: ...Figure 3R Model 1254 Block Diagram 1254 Reference 8...