RF Engineering
Standards of FM Allocation and Interference
The simple view of interference meaning overlapping signal contours tends to overstate the area of potential interference. Jeremy Ruck explains.
Alternate Propagation Models
While the FCC designed its pattern modeling method to be reasonably accurate over a fairly broad slice of circumstances in the United States, it tends to fall apart in situations in which terrain is abnormally smooth or cases where a particular propagation path has some fairly significant undulations.
Testing Antennas with a Network Analyzer
Network analyzers come in two flavors: scalar and vector. Jeremy Ruck explains their use.
Selecting an FM Antenna
Regardless of which antenna you select, the best quality antenna you can afford should be chosen as this is the last item in your transmission chain, and the last point over which you have control of your signal.
AM Tuning Networks
The L network is the simplest of the impedance transformation networks, and is the basis for the more complex T, Pi and other types of networks.
Update on LPFM Rules
The connection between LPFM and translators is a result of the necessary implementation of certain provisions of the Local Community Radio Act of 2010 (LCRA).
Prior Coordination for STLs
No doubt, you have received frequency coordination notices. These notices form one side of the coordination process. It's up to you to follow through to avoid potential interference.
Translator Rules Revisited
Some important events relating to translators warrant some attention.
Understanding Tee Networks
The tee network seems almost magical as it has the ability to transform between almost any two complex impedances using only reactive elements.
Directional Antenna Basics
Jeremy Ruck reviews the basics of directional antenna arrays.
Disaster Recovery
It is prudent to create and maintain a plan for disaster recovery at your facilities, which includes maintaining a strong working relationship with your consulting engineer.
RF Safety
FCC rules, IEEE and NCRP standards are designed to reduce the potential for human danger.
Tower Maintenance
First and foremost in any tower maintenance program is to build a solid relationship with a tower crew; and you get what you pay for. Jeremy Ruck explains.
Method of Moment Proofs
At the heart of the moment method proof is a computer model using an appropriate software package, however, the moment method proof, is not applicable in all cases or array designs.
Translators Today
FM translator service, since its inception in the very early 1970s, has been subjected to several major technical overhauls.
Calculating STL Fade Margin
Understanding the mechanics of your RF program delivery system, and maintaining a keen grasp of the associated fade margin can go a long way to diagnosing the rare, but ultimately problematic impact path failure can have.
Smith Chart Basics
One good working definition of the Smith chart is that it is simply a graphical calculator for normalized impedance and associated RF parameters.
Transmission Line Maintenance
The bottom line is that without maintenance, transmission line will ultimately fail. The good news is that with regular and periodic inspections, the likelihood of unplanned failures is greatly reduced.
Effects of Tower Standard 222G
The bottom line is that Revision G is a good thing, and the standard authors have crafted an excellent standard.
Third-Adjacent Protection Review
One of the hallmark missions of the FCC is to promote the use of the radio spectrum; the corollary is that the Commission ends up being a traffic cop to eliminate interference, more accurately stated as reducing interference.
Grounding standards for broadcast
While there are similarities between various grounding methodologies, asking 10 engineers for their opinions will probably return a minimum of eight different and valid recommendations.
The Phasor
The upcoming generation of radio engineers will encounter a new ease of measurement as a fact of the Commission's new directional antenna proof rules.
Using the operating impedance bridge
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.
Living with the FCC - a History
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.
Thoughts about NEC 4-1
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.
