Monday Morning Coffee and Technical Notes

April 27, 2026 View as Webpage

Reviewing Air Flow

I recently listened to a most interesting and informative radio talk show on AM radio (yes, they still do exist). This was a home maintenance show covering HVAC systems. While it was focused on home systems, there were some great points that apply to studio and transmitter sites as well.

Highlights of the program included:

1. Inspection of the duct system for leakage. Proper installation of all connections and joints will help increase the efficiency of the air flow. Also ensuring the return and feed ducts are located so the air circulates correctly in the area.

2. Systems and equipment that utilize “squirrel cage” fans should be clean regularly, since dust and grime can accumulate on the fins, reducing air flow. While cleaning don’t forget the coils on outside units (be careful not to bend coils which can create other issues).

3. We all know the importance of changing replaceable filters regularly. Use the correct filter for the equipment. Filters use a MERV (Minimum Efficiency Reporting Value) rating.  The higher the MERV rating, the more efficient a filter will be at capturing airborne particles. However, a filter with a high MERV rating has more resistance in airflow and an increase in pressure on the fan.

4. Most importantly, secure the services of a professional HVAC company to conduct a thorough inspection and service of your major system. This should normally be done in early spring before temperatures begin to rise.

NAB Convention

The 2026 NAB Convention is over and vendors are packing up all their goodies. NAB reports attendance was around 58,000 with approximately 48% of this year’s visitors attending the NAB Show for the first time.

If you were unable to attend the Las Vegas event, we invite you to participate in the ABA Engineering Webinar on May 26th. The webinar will feature Paul McLane, presenting a Radio World overview of this year's convention highlights.



The Webinar starts at 10:00 AM central time. Register online here. Note that the date May 26^th is a week later than the normal date of the webinar.

ABA Engineering Academy

The fall schedule for ABA Engineering Academy classes is now set. The Radio class takes place the week of September 28th, while the Television class happens during the week of October 25th. Students from across the country are welcome to attend these classes.

We’re currently updating our study guides and program to include more relevant material for broadcast engineers, as well as new information about emerging technologies like IP for broadcasting, digital audio and video, SMPTE 2110, and ATSC 3.0.

We also offer students the opportunity to take the SBE Certification exam on Friday if desired.



This 5-day class in held at the ABA Training Center in Hoover, AL (Birmingham). Discount rates for students are available at area hotels. More information about daily subjects covered and online registration is available here.

Increase Your Word Power – IFB

IFB, or Interruptible Foldback, is a critical component in broadcast and live sound production, serving as a one-way communication channel that allows directors, producers, or engineers to talk to on-air talent or performers without the audio being heard by the audience.

Commonly used in television, radio, and live events, IFB systems ensure seamless coordination by providing real-time instructions, cues, or feedback to presenters, hosts, or actors while maintaining the integrity of the main audio feed.

This technology is essential for smooth, professional broadcasts, enabling talent to stay informed and synchronized without disrupting the listener or viewer experience.



For on air talent a mix-minus IFB is normally used.  

Sending a mix-minus feed from the studio allows the remote site to hear studio broadcast audio without hearing the audio from the remote site back on delay. Audio sent via satellite or IP technologies from a remote site has inherent delay on both the transmit and return paths. It is a significant distraction for talent to hear this audio back at the remote site on delay.

Understanding the Rules and Regulations 

ABA Engineering Services has initiated a project designed to assist stations in ensuring their EAS systems are fully compliant with FCC Rules and Regulations. The ABA operates a dedicated EAS monitor server that oversees EAS equipment and provides notifications regarding any issues identified. This service is offered at no cost by the ABA.

To facilitate programming your Sage Endec to participate in this service, we will require either remote access to your unit or an on-site visit to your station.

If you are interested in this complimentary service, please respond to this email and provide the serial number of your Sage device (found on the back of the unit and beginning with the letter "B").

To assist further, please provide the current software version installed on your unit. This information can be obtained by rebooting the unit—simply unplug it, wait a few seconds, then plug it back in. After the unit has restarted and the display returns to normal, press the button below "Messages." The operating firmware version will be listed; the current version is 96.01.

The ABA is committed to supporting you in achieving and maintaining compliance. Additionally, we offer monitoring services for DasDec units. For more details regarding DasDec units or any questions concerning this service, please contact ABA Engineering Services.



Please note that this monitoring service does not substitute the FCC requirement for stations to maintain a "Station Log".

Lan Installation Codes

As more and more stations switch to IP infrastructures, care must be taken to adhere to local and national code.

Building and safety codes control how cables integrates with the construction and fire protection systems of a facility. The National Electrical Code (NEC), published by the National Fire Protection Association, is the primary regulatory reference in the United States for low voltage cabling. It specifies plenum versus riser versus general-use cable ratings, dictating which jacket compounds are permitted in air-handling spaces, vertical shafts, and standard building cavities.

Ignoring the NEC’s cable jacket requirements isn’t just a compliance risk; it’s a life safety failure that can result in permit rejection, project shutdown, or liability after a fire event.

Local jurisdictions adopt the NEC on their own schedules and sometimes amend it, so your project team needs to verify which edition and which local amendments apply at each job site.

Read more about construction codes at this site

Pro Audio – Steaming Live Events

FOH (Front of House) and livestream mixes are NOT the same thing.

In the room, your mix is working with:

·       Natural acoustics

·       Stage volume (amps, drums, wedges)

·       The energy of the room

Online? None of that exists. Your livestream mix is:

·       Completely isolated

·       100% dependent on what you send it

·       Experienced through phones, laptops, and earbuds

The real solution isn’t a quick fix…

It’s building a dedicated livestream mix. That usually means:

a separate bus (or even a separate console)

·       Different EQ and compression than FOH

·       Intentional balance for listeners, not the room



In today’s world, your livestream isn’t secondary, it’s part of your front door.

Earl we have got to do something about the wiring closet!