| Date |
Fact of the Day Topic |
| August 1 |
Electrostatic Discharge Risks to Equipment Humans
become electrostatically charged as they do ordinary things such as ... |
| August 2 |
RMS or Effective Voltage The amount
of power being delivered to a DC circuit load can be calculated easily
by dividing the load resistance into ... |
| August 3 |
Quantum An observable quantity is said
to be quantized if its magnitude is restricted to a discrete set of values
throughout at least part of ... |
| August 4 |
Light Speed Measurement Light and radio
waves are both electromagnetic radiation. The difference between them
is merely frequency (or ... |
| August 5 |
Antenna Tuner Circuits A variety of
antenna tuner circuits can be used in both feed-line-to-antenna and feed-line-to-radio
applications ... |
| August 6 |
Logic Logic is a study of sound reasoning
that focuses on a study of arguments. An argument is a series of statements
called premises that lead to ... |
| August 7 |
Surface Mount Technology Nearly all
electronic devices manufactured today use surface-mount technology. There
are several reasons, but ... |
| August 8 |
Can Electromagnetic Radiation be Stopped? Almost
everyone knows that electromagnetic radiation travels at the velocity
of light in a vacuum ... |
| August 9 |
Static Crashes It is well known that lighting
causes static crashes, but it isn't so well known ... |
| August 10 |
Earth's Resistance The earth's DC resistance
in a circuit where the earth constitutes one of two conductors is essentially
zero ohms, because ... |
| August 11 |
Feed-Line Impedance Conditions for maximum
power transfer through a transmission line require source and load impedances
to be conjugates, respectively ... |
| August 12 |
Self-Inductance Self-inductance is a property
of electrical circuits that causes them to oppose a change in current
flowing through them ... |
| August 13 |
Radio Line-of-Sight Variations in the atmosphere's
refractive index with height cause the paths of direct radio waves between
transmitting and receiving antennas ... |
| August 14 |
Tropospheric Reflections Small discontinuities
in dielectric constants at the boundaries of different air masses often
cause tropospheric reflection of VHF, UHF and microwave ... |
| August 15 |
Space-Wave Intensity A horizontal half-wave
dipole transmitting antenna radiates energy toward both sky and earth.
The portion radiated toward earth reverses phase ... |
| August 16 |
RMS Current RMS is an abbreviation for
the 'root mean square' mathematical process of determining the effective
value of an alternating current ... |
| August 17 |
Great Circle Route Radio Amateurs often
refer to the 'great circle route' between two stations, but what exactly
is a 'great circle route?' ... |
| August 18 |
Why is Transmitter Output Called Power? In
mathematics, a power of a number indicates repeated multiplication. For
example, 'x to the third power' means 'x multiplied by itself three times.'
... |
| August 19 |
Carbon Resistor Noise Resistors composed
of carbon granules generate far more noise than thermal agitation noise
when current flows ... |
| August 20 |
Thermal Agitation Noise Noise voltages
due to thermal agitation in resistors set limits on the smallest signal
voltages that can be amplified without being lost ... |
| August 21 |
Magnetic Reluctance The magnetic circuit
property that determines the relationship between magnetic flux and corresponding
magnetomotive force (mmf) is called ... |
| August 22 |
Ferrite-Core AC Hum Precaution The nonlinear
magnetic characteristics of ferrite makes ferrite cores sensitive to
hum pickup from stray 50/60 Hz magnetic fields ... |
| August 23 |
Ferrite-Core Temperature Precaution The
inductance of coils wound on ferrite cores change substantially above
a certain temperature that depends on the grade of ferrite ... |
| August 24 |
Inductance The practical unit of inductance
is the henry. However, the inductance of most inductors is expressed
in millihenrys or microhenrys ... |
| August 25 |
AM Broadcast Band Filters The performance
of most HF communication receivers is significantly degraded by high-power
AM broadcast stations... |
| August 26 |
Antenna Array Patterns Antenna array patterns
determined by multiplying the patterns of individual elements tend to
be only approximations ... |
| August 27 |
Realization of Antenna Patterns Realization
of calculated antenna patterns requires great skill in design, adjustment,
and attention to details ... |
| August 28 |
RF Linear Amplifiers SSB, FM and FSK transmitters
nearly always have low-level modulators. AM transmitters can have either
low- or high-level modulators ... |
| August 29 |
Sound Loudness Most people do not realize
that because of the non-linearity of human hearing it is necessary to
increase mid-frequency sound power ten times ... |
| August 30 |
Wire Inductance vs. Frequency Wire inductance
changes somewhat with frequency because of the way current distribution
within a wire changes with frequency ... |
| August 31 |
Feed-Line Impedance Matching Engineers
discovered long ago that any electrical circuit that can be constructed
from a finite number of lumped inductor and/or capacitor elements ... |
