Monday Morning Coffee and Technical Notes

March 18, 2025 View as Webpage

ABA Engineering Academy

Special note to television engineers

The next ABA Engineering class is scheduled for television engineers the week of April 28^th. 

Students are already registering for this important class where we cover basic television operations along with the latest in ATSC 3.0 and SMTPE 2110.



The schedule for the fall classes are Radio September 22 – 26 and television November 3 – 7.

Engineering Notes for August

Engineers should be aware that the end of March brings with it the requirement to conduct the Quarterly Tower Light system inspection.  These inspections cover not just making sure the lights are working but also the control system and alarm reporting. The best way is to simulate mode changes and light failure alarms.

A record of the quarterly inspection should be kept either in a transmitter maintenance log or engineering files.

The end of the quarter is a good time to review the station logs for the first quarter. Checking these logs quarterly helps in keeping reports up to date.

Not a technical issue, but equally important is the requirement of stations to file the first quarter “Issues and Program Lists” by the 10^th of April. 

Engineers should remind management of this requirement.

Monday Morning Coffee and Technical Notes

Our popular weekly newsletter “Monday Morning Coffee and Technical Notes is read by over 900 broadcasters each week. We now offer archives of past newsletters in case you miss one or need to read again.

Simply click on this link to access the list. We will be adding early issues shortly.

 Understanding KVA

Power ratings are expressed in different forms such as watts and kilowatts, amperes or amps, volts, and also in kVA, but what exactly is kVA?

Outside the generator industry, the term kilovolt-amperes (kVA) is not well known. A kilowatt (kW) is a much more common term and is how electrical items in your home or business are rated, you may even notice it quantified on your electricity bill so it is much more relatable, but what exactly is kVA, why is it used and how is it calculated?

We can refer to kW (kilowatts) as actual power, it is the amount of power that is converted into an output. While kVA (kilovolt-amps) is a measure of apparent power: it describes the total amount of power being used by a system, for example in a 100% efficient system kW would equal kVA exactly. However, in reality electrical systems are not 100% efficient and so not all of the system's apparent power is being used for useful work output.

The key is something called Power Factor. Most 3 phase generators have a power factor of 0.8. When you know this, it is easy to convert kVA to kW because you know the efficiency level of the electrical system in question. Electrical efficiency is usually expressed as a power factor in between 0 & 1, therefore the closer the power factor is to 1, then the more efficiently the kVA is being converted into actual kilowatts.

Conversion is simply… kVA to kW Apparent power (kVA) x power factor (pf) = actual power (kW) e.g. 100 kVA x 0.8 = 80 kW

kW to kVA Actual power (kW) / power factor (pf) = apparent power (kVA) e.g. 80 kW / 0.8 = 100 kVA



information courtesy of ADE

March Engineering Webinar

The ABA Engineering Webinar will be held on Tuesday March 18^th at 10:00 AM central time. The subject will be generators, presented by a representative of Thompson Tractor Co., leaders in generator installation and maintenance. Mark your calendars now for this informative webinar covering sizing, installation and day-to-day maintenance.

Register now at this link.



Scheduled for our April webinar will be Scott Fisher with Hitachi Vantara. The topic is modern day media storage systems, both on site or cloud. The date for this webinar is April 15^th.

  Pro Audio – SPL Issues  

If you have been involved in mixing sound for a church service, I am sure you have had someone say “Can you do something with the sound? It’s too loud in here”.

Church FOH engineers learn quickly that it may not be the overall SPL in the room but could often be a build up in certain frequency ranges. That is why it is important when installing a new sound system to tune the room. If there has been any architectural change made, then you should retune the room.

While it is best to have an experienced sound engineer tune the room (they have all the necessary test equipment and knowledge), if a real time audio analyzer is part of your mixing console you can get pretty close to what is needed.

Basically what you are looking for is any build up of SPL at different frequencies. This is caused by room physical acoustics. Using the system graphic equalizer, seek to reduce those frequencies that are causing the buildup.



Once those frequencies are corrected, then listen to several reference tracks and touch up the EQ to make the system open, intelligible, and fits with the human hearing curve (Fletcher Munson curve)  

Earl let me see those plans again!