The development of the operating impedance bridge by Delta Electronics about 40 years ago made antenna impedance measurements not only much easier to perform, but more accurate.
John Battison looks back on the early days of the FRC and the FCC, recalling some of the simpler times and possibly better methods of another time.
As time passed and DA design work received increasing attention, it became obvious that more information was needed about how the antenna worked in its environment once constructed.
MEOV offered a wonderful means of providing a way around a potential difficulty in meeting the approved radiation pattern.
The NEC programs offer a great improvement over the slide rule era when the sheer volume of manual operations involved tended to influence full and comprehensive searches for perfection.
A transmission line is a far more complex piece of equipment than many people realize. In its simplest form it may be considered as just a pair of wires merely carrying ac power.
Sometimes we tend to forget some of the fundamental facts of electronic life involving radiation which, after all, are requisite for radio transmission.
The average ground system is quiet, dependable and retiring, performing its work efficiently, without demand for attention. Unfortunately, too many stations try to economize when installing or maintaining ground systems.
The last link in the broadcast chain under the control of the broadcast engineer is the transmitter and antenna system. From then on quality of reception is left in the hands of the listeners. Thus it puts the onus of transmitting the best possible signal on the station engineer.
When monitor points suddenly exhibit surprisingly high field strength, one's first inclination is to look at the previous logs and ask the technical staff about the monitoring point's history
Early in the 1930s French engineer Henri Chireix devised an ingenious method of modulation that he named most appropriately out phasing. It was based on the result of combining two out-of-phase voltages. This produces a fluctuating signal voltage that varies in amplitude as the audio signals change. This voltage, after amplification, drives a power amplifier stage with properly amplitude-modulated RF.
There are many lists extant of precautions to take before working with high voltage pieces of equipment. Lethal incidents may be more often caused by completely unexpected circumstances than from pure, careless accidents.
Radio-engineering work is very involved with filters of one kind or another. The science of broadcasting depends on the correct passage of various frequencies through differing pieces of equipment. Some frequencies are in the audio range and others are in the RF domain.
Tower lighting requirements, which are specified in part 17 of the Commission’s rules, sometimes come as a financial shock.
When the early pioneers such as Alexanderson, Fessenden and Marconi commenced the production of non-ionizing radiation no one limited their RF levels, blamed their antenna towers for the deaths of migrant birds, or complained about ugly towers spoiling picturesque views.
Your new or latest station license has arrived. How you deal with it can have a huge effect on your future.
Before any useful maintenance can be performed it is essential to know how a system is supposed to operate and also know the licensed operating parameters. A copy of the latest proof of performance and the current license are a good place to start.
New construction can distort an AM station's anticipated service contour. This primer reviews the basics of antennas and RF propagation.
At one time, tower climbing and inspections were something that everyone and anyone could do. In today's safety-conscious world, it pays to play by the rules and do it right.
On the surface, three-phase operation may appear to be a lot more complicated than single-phase work.
Today's broadcast engineer has a much easier row to hoe than his counterpart in the middle to latter part of the 20th century.
While they seem simple enough, transmission lines are actually very complex in nature. Their size, length and type are all important considerations when designing an RF system.
While negative towers are not as frequently used in directional antenna array designs, they can still be found in use. What exactly is a negative tower, and what does it do that is so different from a normal tower?
The new specification's table of contents lists 15 main topics or objectives, each of which may have as many as eight subsections.
When first developed, the Doherty amplifier gained a reputation for difficulty in adjustment and consistent operation. Since then, it has proven to be a stable and reliable transmitter design.