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When the FCC was created in 1934, it began licensing radio stations and station operators, and it introduced First- and Second-Class Radiotelephone Operator written tests and operator licenses. In 1941, patent deals were announced for US TV transmission and receiver standards, and the black-and-white NTSC standard and commercial TV were born. When commercial TV was ramping up following World War II, a First-Class radiotelephone operator license was required to be a chief engineer and to work on TV transmitters.

The FCC added a Third-Class radiotelephone license in 1953 so DJs could operate radio transmitters. Written tests for FCC radiotelephone operator’s licenses were administered in FCC field offices, and it tested the applicant’s knowledge of broadcast radio and TV rules, regulations and procedures, electronics theory, and RF transmission. Operator’s licenses were renewable every five years without further testing.

In 1983, the FCC stopped First Class license testing and began issuing the General Radiotelephone Operator License (GROL). A GROL requires a one-time test, administered at about a dozen Commercial Operator License Examination Managers (COLEMs) nationwide, and good for life.

It’s not necessarily required for all engineering jobs in radio and TV broadcasting, but a GROL is one of the most widely recognized and respected TV engineering credentials. With a GROL, you are more likely to keep your distance from a transmitter about to fail. The lack of high voltage in today’s solid-state PA transmitters seems safer until you notice the 50 Volt, 1500 Amp power bus is exactly where your steel wrench will fall if you drop it. Be careful.

Government Authority

In the US, the FCC has many rules and requirements for television stations beyond RF rules. Many FCC requirements, such as the station’s local public inspection file, the recently revoked EEO (Equal Employment Opportunity) filing, the license renewal process, fees, and mandatory electronic filing requirements are usually handled by the business manager, as are petitions to deny or informal objections filed after a station’s license renewal application. The last day for anyone to file a petition to deny license renewal is one month before the license expiration date.

I once worked at a TV station where the engineering secretary wanted to be on TV. She felt discriminated against and filed a timely petition to deny with the FCC. In less than a week, she became the station’s latest on-air news reporter. I’ve known of other denial petitions that weren’t as successful, usually from unhappy viewers or politicians.

Every country around the world has a national department dedicated to electronic communications and regulating RF technology. In the UK it is OFCOM and each EU country has their own with co-ordination between them handled by EPRA (the European Platform of Regulatory Authorities). In the US, it’s the FCC. The regulations are broadly similar but you should check your own local authority regulations.

Most of the RF transmission rules and regulations in the US are defined in Title 47 of the United States Code. The latest update is a FCC Small Entity Compliance Guide Amendment of Part 73 Fact Sheet dated 31 August 2023 at DA-24-406A1.pdf (fcc.gov). This  document updates the rules and definitions to say that all TV transmission is digital, and there are only Full-Power TV and Class A TV (generally LPTV) stations.

Monitoring, Measuring & Managing RF

Broadcast transmitters are designed for reliability and built to be easily repaired and thoroughly monitored and measured, locally and remotely. At a minimum, monitoring a remote transmitter site at the studio includes measuring power supply voltages, currents, TPO, SWR, frequency, modulation, return demodulated video for QC, and often includes security cameras and alarms. Most monitoring at this level can be automated and send alarms to engineers triggered by presets. Most transmitting parameters can be monitored at dial-up speeds, but remote control and return video requires more bandwidth.

Monitoring at the transmitter site can be more intense. It may require a traditional hardware based TV spectrum analyzer from one of the small selection of vendors who manufacture them or software-defined receiver (SDR) with TV broadcast software to identify problems. You hope that once the transmitter is commissioned, your problems are over. Not always.

I was the contract transmitter engineer at a TV station about a decade ago that didn’t own a spectrum analyzer. The engineer that commissioned the transmitter brought his own analyzer and readings seemed within specs and relatively stable when he signed off the project. A few years later, we received a call from the cellphone company that we shared a tower with, complaining that our signal was interfering with some of their gear.

I met with the cellular tech at the tower site, and he showed me our overlapping signal on his spectrum analyzer. I removed our mask filter, reduced TPO to minimize interference, and returned the filter to the manufacturer for service. I wanted to experiment with it, but there were too many adjustments and slugs on the unit to touch any of them.

The manufacturer found and fixed the problem but couldn’t identify its cause. I don’t believe it was lightning because our antenna was side-mounted, half-way up the tower and we had lightening protection. There was no physical evidence that anyone had used the rigid transmission line for target practice. The SWR never changed.

Problem Solver

At many TV stations, a handful of engineers are responsible for all RF things in a facility, from garage door openers and cellphones to routers and Wi Fi systems. TV engineers have become the local spectrum police by default. A good spectrum analyzer can help identify new sources of RF problems and surprises.

If a wireless mic doesn’t work and its batteries are okay it’s a crisis, right? Is someone else using this channel? I’ve seen other stations from other markets doing live shots near my location and receive site that interfered with my RF systems. A spectrum analyzer can answer many questions and help keep everyone happy and legal. At the end of the day, it’s all about being a good neighbor.

RF spectrum management is engineering territory, and it’s the responsibility of station RF engineers to protect the station license and monitor daily operations to stay within FCC regulations. Don’t depend on the FCC to protect you.