Monday Morning Coffee and Technical Notes

October 6, 2025 View as Webpage

Important Update!

As everyone is aware, the FCC has implemented its plan for an orderly shutdown and suspended most of its operations and websites. This was due to a partial lapse in Federal Government funding arising from lack of Congressional Appropriations, termed a government “shutdown." 



The Commission has announced that most filing deadlines will be extended to the next business day following the resumption of normal FCC operations. Communication attorneys recommend completing and uploading required items to minimize confusion and potential delays when the shutdown concludes. Required documents can be filed as long as the FCC public file website remains accessible.

If the FCC web site is not working on October 10^th. prepare a memorandum stating that you had the document ready on the deadline, attempted to upload, but the system was down. Save the memorandum for future use in uploading and for reference when your station’s license renewal application is filed. When the FCC’s system is eventually up and running, upload the issues-programs list for the 3rd Quarter along with your brief memorandum. 

A copy of the FCC’s Public Notice, Impact of Potential Lapse in Funding on Commission Operations, DA 25-922, released September 30, is attached, which address filings and deadlines.

ABA Engineering Academy

As a reminder the ABA Engineering Academy will hold the Television Broadcast Engineering class the week of November 3^rd – 7^th, 2025.

This an excellent opportunity for new engineers to receive valuable technical training, including basic electronics, analog and digital audio, history of television, technical operation of NTSC, ASTC 1.0 (8VSB), ATSC 3.0 and SMPTE 2110. Seasoned engineers can use it as a refresher course as well as learning about ATSC 3.0 and SMPTE 2110.

This class runs from 8:30 AM – 4:00 PM Monday through Thursday. Friday is reserved for those wishing to take the SBE Certified Broadcast Technologist exam.

The class is offered at no charge. By the Alabama Broadcasters Association. Click here to view the daily schedule and registration.

Understanding Degrees

Ever looked at your AM license, especially a directional license and scratched your head over how do I figure out how tall are these towers and how far apart are they spaced in feet? 

They are listed in degrees.



Well it is just simple math. But first you must know what frequency these towers will be operating on. Radio waves travel at the speed of light which is 300,000,000 meters a second. The basic formula to determine the wavelength is 300,000,000 divided by the frequency in Hertz.

Engineers over the years have simplified the formula to 984 divided by the frequency in Megahertz. This gives you the answer in feet. It’s the same formula just using smaller numbers.

Let’s assume the station is operating on 740 kHz. Using this formular it would give you a wavelength of 1,329.73 feet. We know that there are 360 degrees in one wavelength. Then dividing 1,329.73 feet by 360 would equal 3.69 feet per degree. The FCC license indicates the towers are 78.5 degrees tall. 3.69 multiplied by 78.5 gives you the height of the towers 289.66 feet. The distance between the towers? 3.69 multiplied by 105 = 387.45 feet.

DNS Revisited

Addresses are fine, but you can’t really memorize them. The Domain Name System (DNS) is what creates those web addresses that we are most familiar with. It's DNS that maps IP addresses names.

The Internet Corporation for Assigned Names and Numbers (ICANN) maintain a list of top-level domains, such as .com and .org. There are more than 250 global TLDs, as seen on ICANN’s microsite.

Each machine has a host name file somewhere that maps names to addresses, but this gets unwieldy even with more than a few machines. Just try to imagine millions of machines around the world. DNS is a decentralized system, which makes this process much easier.

The key to DNS’s success is its ability to perform recursive lookups. If a DNS server gets a request for a name it doesn’t know, it will ask another server, which will ask another server and so on until it gets an answer. DNS servers typically cache their names to make this faster.



Despite its simplicity in operation, DNS can be challenging to set up, and the process includes more detail than can be covered in this article. Fortunately, there are plenty of guides that can outline this sometimes daunting process. A good one is Craig Hunt's "TCP/IP Network Administration." (Learn more in DNS: One Internet Protocol to Rule Them All.)

Pro Audio –  Compressors versus Limiters

Compressors are commonly used for many audio applications and functions by lowering the uppermost dynamic range of a signal at a set threshold. Once the signal exceeds that threshold, the compressor will engage and reduce it, by a set amount. Compressors also allow the engineer to determine how fast the gain reduction will engage and how slow it will be released.

How severely the compressor reduces the signal, is determined by two parameters: ratio and threshold. A ratio of 2:1 or less is considered mild compression, reducing the output by a factor of two for signals that exceed the compression threshold. Ratios above 10:1 are considered hard limiting. Assuming a nominal input-signal level, as the compression threshold is lowered, more of the input signal is compressed.

A well-designed and properly adjusted compressor should not be audible. Too much compression can destroy the acoustic dynamic response of a performance.

The question is sometime ask isn’t a limiter and compressor the same thing. Well the answer is “it depends”

At the simplest level, a limiter is a compressor that is set to prevent any increase in the level of a signal above the threshold. A true analog peak limiter is not just a compressor with a high ratio. A compressor’s detector circuit is usually designed to detect RMS, or average, levels, so transient peaks will usually overshoot a compressor’s threshold level. A true peak limiter employs a detector circuit that responds to peak energy levels and thus reacts faster.



Limiters are like super compressors. They are meant to function over very fast periods of time and apply super high ratios for gain reduction.

Earl, don't think this is going to be a good day!