Monday Morning Coffee and Technical Notes

November 24, 2025 View as Webpage

C-Band changes may be coming soon

Last Thursday the Federal Communications Commission   took a critical step toward releasing a large swath of mid-band spectrum for America’s innovators when it voted to propose rules for 5G and 6G services in the Upper C-band (3.98-4.2 GHz). 

This proceeding will examine a range of options for the Upper C-band, including auctioning up to 180 megahertz, with the ultimate goal of maximizing the amount of spectrum for next-gen wireless services as generational aviation safety upgrades occur in the adjacent band.

 This represents a milestone in implementing the spectrum provisions of the One Big Beautiful Bill Act. That legislation requires the FCC to complete a system of competitive bidding for at least 100 megahertz in the Upper C-band no later than July 2027. 

The Notice of Proposed Rulemaking seeks comment on how to accommodate incumbent satellite users and other services presently in the Upper C-band. It also explores ways to promote co-existence with adjacent band radio altimeters, along with a range of related technical issues. The Notice reflects input and coordination from the FCC’s federal partners, including the FAA and NTIA. 



The ABA will monitor and update on the proposal's progress.

IT Upgrades

In today’s digital-driven world, IT infrastructure plays a crucial role in ensuring the smooth operation of businesses. As technology continues to evolve, organizations must upgrade their IT systems to stay competitive, improve efficiency, and enhance security. 

Often these changes involve a change in Internet Service Provider or installing a new firewall. Before making any changes, review the present system, identify devices that require dedicated circuits or URLs. Due to the way broadcasting operates today, the need for secure remote access to the station IT system is a must. With the requirements outlined, take time to sit down with a qualified IT engineer and discuss the system.



Also remember that technology evolves rapidly, and upgrading your IT infrastructure should not just focus on current needs but also future requirements. Opt for scalable solutions that can grow with your business.

Investing in a future-proof IT infrastructure ensures that you won’t need frequent overhauls, saving both time and money in the long run.

ABIP Inspection Schedule

We are busy working on the Alternative Broadcast Inspection schedule for 2026. We have a list of those stations in Alabama that are due for a renewal inspection, however we encourage stations that have gone through an inspection in the past years to check the expiration date on their Certificate of Compliance and let us know if station will need an inspection during 2026.

If you have never gone through a ABIP inspection this will be an excellent opportunity to get on the list. These inspections are designed to review your station compliance with all current FCC rules and regulations. If any issues are found that need to be addressed, you will receive a written report outlining the issue and information on correcting. It is totally confidential between the inspector and station. 

Inspections are offered as a free service for all members of the Alabama Broadcasters Association. Stations will be billed for travel expenses incurred by the inspector.

Contact us today if you have any questions or to sign up for an inspection.

Weekly e-newsletters

ABA Engineering Services sends out two different weekly e-newsletters. The “Monday Morning Coffee and Technical Notes” is geared toward technical professionals and highlights the latest news, features, and articles that impact engineering departments in both broadcast and professional audio.

Managers and operators are eligible to receive the “Broadcasters Operation Notebook,” which is distributed every Tuesday and contains the latest information regarding FCC rules, filing deadlines, and operational guidelines.

To sign up for these free newsletters by sending a request to the ABA Engineering Services.

Back to the Basics – IFB systems

An IFB system is crucial for live radio or television production, enabling clear communication with talent both on set and remotely to keep everyone coordinated.

IFB, or "interruptible foldback," is a one-way audio feed that lets producers or directors interrupt program audio to cue talent.

Alex Milne writing in RF venue says, “The content of the program can be nearly anything related to the production—a local program (like a TV show or news), a remote program, cues, music, countdowns, even dead air.

What distinguishes an IFB from a simple one-way feed is the ability of a producer or director to interrupt the feed to deliver information to the talent and then “fold back” the program to that talent, as when a producer informs a news anchor of breaking news.”

The setup is commonly known as “mix-minus IFB,” where the talent hears everything except their own voice. By doing this, latency problems are avoided and don't disrupt live reporting. Today’s audio consoles and routing systems typically generate mix-minus feeds automatically for the talent.



It is essential to verify that each member of the talent receives accurate audio sources, as incorrect IFB feeds can significantly compromise the quality of a production.

Pro Audio –  Intersample Distortion             

When working with digital audio one must be aware of an issue called “Intersample Distortion.

Intersample distortion arises in digital audio systems due to the discrete nature of sampling. When audio is recorded or processed digitally, the continuous analog waveform is sampled at fixed intervals (sample rate). While the digital samples themselves may remain below the maximum 0 dBFS (decibels full scale), the reconstructed analog waveform between these samples can exceed this level, creating peaks that are not captured directly in the digital sample values. These are known as intersample peaks (ISP), and when they exceed hardware or format limits, they produce intersample distortion.

If the audio level gets to close to the digital audio clip level of 0 dbFS The digital to analog converters (DACs) reconstruct the continuous waveform through interpolation or low-pass filtering of the samples. This reconstruction may identify intermediate peaks above 0 dBFS even if all recorded samples are within limits.

To avoid this issue leave a margin (typically 2 to 3 dB) below 0 dBFS when mastering or limiting. This ensures that reconstructed analog peaks do not clip, even with extreme dynamic content.

Also to measure and limit the true peaks rather than only sample peaks. True peak meters oversample (4×–16×) to detect potential intersample peaks and dynamically attenuate them.