| Date |
Fact of the Day Topic |
| March 1 |
LF & MF Nondirectional Radio Beacons The
first nondirectional radio beacon (NDB) was placed in service in 1921.
It was ... |
| March 2 |
Forward-Scatter Antenna Considerations Ionospheric
forward-scatter propagation makes communication possible beyond ... |
| March 3 |
Tesla's Radio-Controlled Boat On May 18,
1899, Nikola Tesla demonstrated a six-foot-long radio-controlled boat
to ... |
| March 4 |
Antenna Loading Capacitors It is well known
that a loading coil can be connected in series with a short antenna to
... |
| March 5 |
Guy Insulator Capacitance It is well known
that antenna tower metallic guy cables should be separated into ... |
| March 6 |
Removing Copper Antenna Tarnish Copper tubing
or large-diameter bare copper wire is sometimes used to ... |
| March 7 |
Lead-Free Solder An EU directive restricts
the use of certain hazardous substances, including lead, in ... |
| March 8 |
Mathematical Meaning of 'Normal' Familiarity
with common meanings of the word 'normal,' such as 'being approximately
... |
| March 9 |
3860 kHz Interference If you hear a rough-sounding
and very broad signal centered at 3860 kHz there is a high probability
that ... |
| March 10 |
Three Radio Direction-Finding Methods A
wide variety of radio direction-finding systems have been developed employing
... |
| March 11 |
Doppler-Shift Radio Direction Finding Radio
amateurs most often use the directional characteristics of antennas to
find bearings ... |
| March 12 |
Quasi-Doppler-Shift Radio Direction Finders Servo
Corporation of America patented Quasi-Doppler-Shift Radio Direction Finders
... |
| March 13 |
Piezoelectric Crystals Quartz is used almost
exclusively to produce frequency-control crystals, because of its ... |
| March 14 |
Linear Circuits Any circuit that has a
ratio of output-signal to input-signal (called a transfer function)
that is not ... |
| March 15 |
Nonlinear Circuits A nonlinear circuit
has a ratio of output-signal to input-signal (a transfer function)
that is a function of ... |
| March 16 |
Is an Unmodulated Carrier a Carrier? Ask
a radio engineer what a carrier is and you probably will be told that
a carrier is a ... |
| March 17 |
Transmitting Complex Sounds Most common
sounds are complex mixtures of multiple frequencies having ... |
| March 18 |
Phase & Frequency Modulation Difference It
is impossible to change the phase of a sinewave without changing its
frequency ... |
| March 19 |
Mathematical Meaning of Root Lack of knowledge
of the simple meanings of common technical terms can make relatively
simple ideas ... |
| March 20 |
Measuring Tree Branch Height Trees often
support the ends of wire antennas. Regardless of whether a tree is climbed
... |
| March 21 |
Battery Storage Temperature Batteries deteriorate
at various rates continuously from the time they are manufactured ... |
| March 22 |
Battery Self-Discharge All chemical batteries
self-discharge, but self-discharge rates tend to be higher with ... |
| March 23 |
Computer Memory Leaks Computer programs
request blocks of memory from a computer operating system such as ... |
| March 24 |
Computer General Protection Faults Computer
operating systems allocate blocks of memory space and certain other resources
... |
| March 25 |
Meaning of 'Field' The term 'field' is
very familiar to everyone who has studied technical aspects of radio.
Beginners read about ... |
| March 26 |
NiCd Battery Crystalline Formation Newly
manufactured NiCd battery cells contain finely-divided crystals of ... |
| March 27 |
Li-Ion Battery Overcharge Danger Lithium-Ion
(Li-Ion) batteries are different than most types of rechargeable batteries
in that ... |
| March 28 |
Twisted-Pair Balun Wire Two-wire speaker
cable, hand-twisted enamel wires, and other wire pairs with unknown ... |
| March 29 |
Sound Noise-Masking Experiments Egan and
Hake conducted a series of sound-signal noise-masking experiments in
... |
| March 30 |
Rocket-Triggered Lightning It is necessary
to observe lightning at close range to accurately investigate some of
the associated ... |
| March 31 |
Best Place to Stop Interference Where possible,
the best place to stop interference is generally at its source. The reason
is simple ... |
