| Date |
Fact of the Day Topic |
| October 1 |
Tower Guy Load Load in tower guys depends
on the guying arrangement used, the direction of the wind, the amplitudes
of ... |
| October 2 |
Tower Base Foundations Concrete piers generally
make the best tower base foundations. Safe foundations must be ... |
| October 3 |
Tower Column Load Antenna tower column
load sometimes is underestimated by amateur designers. Static tower column
load is the sum of ... |
| October 4 |
Modulation An unmodulated carrier is a
constant amplitude, single-frequency, sinusoidal wave. A carrier wave
must be ... |
| October 5 |
FM Signal Bandwidth The bandwidth of a
frequency modulated signal can be calculated using Bessel functions.
Bessel functions show that ... |
| October 6 |
Receiving Bandwidth Effects The effects
of restricting receiving bandwidths are different for ... |
| October 7 |
VHF Radiation Above the Horizon Most VHF
communication utilizes direct waves rather than sky waves ... |
| October 8 |
Antenna Effective Aperture The effective
aperture of an antenna is sometimes called its capture area. It is the
frontal area from which ... |
| October 9 |
Receiver Noise Figures The importance of
receiver noise figures tend be very different depending on ... |
| October 10 |
Knife-Edge Bending Laboratory experiments
demonstrated long ago that light rays are refracted (bent) when
... |
| October 11 |
Lightning Flashes Lightning flashes usually
consist of 3 or 4 individual discharges called strokes. The individual
strokes ... |
| October 12 |
Determining Coil Distributed Capacitance The
distributed capacitance of a coil can be determined by ... |
| October 13 |
VHF Long-Wires, V-Beams and Rhombics Long-wires,
v-beams and rhombics are rarely used in VHF and UHF applications, mostly
because ... |
| October 14 |
White Noise The power spectrum of white
noise is frequency-independent. Noise with a flat power spectrum ... |
| October 15 |
Feed-Line Irregularities Feed-line irregularities
result wherever line constants change due to ... |
| October 16 |
Cross-Modulation Cross-modulation is a
condition where the amplitude of a signal of one frequency is affected
by ... |
| October 17 |
Transformer Current Inrush AC power may
happen to be applied to the primary winding of a power transformer at
any point in the voltage cycle ... |
| October 18 |
Audio Frequency Response Many years ago
broadcast engineers determined in exhaustive experimental tests with
juries of listeners that ... |
| October 19 |
Electron Velocity in Volts Beginning electronics
students often are puzzled when they find the velocity of electrons expressed
in volts ... |
| October 20 |
Propagation Below 100 kHz At frequencies
below 100 kHz radio waves that have traveled a great distance act
as though they ... |
| October 21 |
Tower Lighting The governments of most
countries require warning lights on all high towers and on low towers
near ... |
| October 22 |
Emergency Power Generators Gasoline is
expensive, difficult to transport, dangerous to store, and deteriorates
... |
| October 23 |
Semiconductor Hole Storage Holes injected
across a semiconductor junction interface from a P-region into an N-region
are capable of ... |
| October 24 |
Matching the Impedance of Space Maximum
power transfer from a line to a load occurs when ... |
| October 25 |
Tower Galvanizing Galvanizing is a name
given to the process of coating a metal with a different metal. The most
common ... |
| October 26 |
Subsurface Antennas Subsurface (buried
or submerged) antennas have obvious military and espionage ... |
| October 27 |
Luxemburg Effect The action of the ionosphere
upon an electromagnetic wave is, at least in theory, ... |
| October 28 |
Electrically-Conducting Shields Both electrostatic
and magnetic radio-frequency fields can be confined to small spaces by
... |
| October 29 |
Magnetic Shields Non-magnetic, electrically-conducting
shields are not effective in shielding ... |
| October 30 |
Antenna Phase Shifters It is common practice
to shift the relative phase and to adjust the ... |
| October 31 |
Broadside Array Gain The power gain of
uniformly-spaced broadside arrays with lengths greater than ... |
