Same, but not the same: broadcast versus amateur radio

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Mark Persons, Paula Persons, amateur radio
Mark and Paula Persons at their ham station.

From the 1920s through the 1960s, almost all broadcast engineers were licensed amateur radio operators. It has changed a bit, but not the importance of being a ham.

Both environments involve getting an RF signal from point A to point B. But it is interesting to note that radio broadcast and amateur radio are similar and yet so different.

For those who don’t know much about amateur radio, I will tell you that communicating locally or internationally, via licensed amateur radio, can be a fascinating and stimulating hobby. There are approximately 700,000 hams in the United States and an equal number in the world.

Physics
Broadcasting and amateur radio operate under the same laws of science. Transmitters, transmission lines, antennas, and receivers form an RF path for transmitting a message.

Broadcast engineers know that signal propagation on the AM and FM bands is drastically different. This is because our FM band is about 100 times the frequency and 1 / 100th the RF wavelength of that of the AM band. Engineers also know that STL signals at 950 MHz are line-of-sight and represent about a 10-fold frequency hopping of FM broadcast frequencies. Each band has its own challenges in getting a usable signal through.

[Read: Mark Persons: “I Never Had a Plan B”]

Amateur radio operators have around 30 frequency bands, with opportunities to explore from the bottom of the AM broadcast band up to GHz and down to the light. Hams are not limited to amplitude or frequency modulation, but often use a single sideband and many modes of digital. A few communicate by teleprinter and / or transmit television pictures to friends.

Yes, some hobbyists still use Morse code to send and receive messages in their hobby. Code fluency is no longer required to get a ham radio license, but it is a fun personal challenge for many.

Similarities
What I find useful is to apply what I know about amateur radio in my work as a broadcast engineer.
And, of course, it works both ways. Forward power, reflected power, transmission line attenuation, antenna gain, transmitter power amplifier efficiency, and path loss are all dictated by the same rules. . The mysteries and science of RF propagation to a new broadcast engineer are facts of life for radio amateurs.

Hams rise to the challenge of propagating waves every day. Communication across the world via radio waves may be lost on the internet / millennials, but it can be a real challenge for those who want more from life.

International contacts are frequent during peaks of the 11-year solar cycle. With 400 watts, I was able to contact a station in Antarctica from home using a good antenna. I made contact with Europe, Japan, Russia and even Australia with only 100 watts from my car, mostly 20 meters (around 14 MHz). Talk about distracted driving! Australia is halfway across the world from Minnesota. The RF path between us was only open for half an hour. It’s always a pleasure to be on the right frequency at the right time.

As with broadcasting, profanity is not allowed on amateur radio. Do not confuse amateur radio with Citizens Band. CB is a sad story of people transmitting on the 27 MHz band using foul language and unacceptable social conduct. Hams can lose their licenses for this.

Differences
Broadcasters are licensed for specific frequencies at specific power levels.

Hams can operate at up to 1500 watts of RF peak power in most frequency bands. Good operating practice is to transmit with only the amount of energy needed to reach the other end. Some like the challenge of reaching out to amateur stations around the world with one watt or less of power.

Broadcasters modulate AM, FM and / or digital depending on their license. FCC rules impose tightly controlled occupied bandwidths. Hams select one of many modulation types, although the bands are divided into segments for each modulation type, just to keep order.

Broadcasting transmitters are required to maintain a strict frequency tolerance. Radio amateurs can roam the authorized frequency bands looking for a clear place to call CQ (call anyone who is listening and who might want to speak.) They can and do easily converse with radio amateurs from foreign countries. It’s a lot more fun and stimulating than just listening.

Hams do not “diffuse” in a city or in the world. They do not broadcast music or broadcast programming like you will find on the AM and FM broadcast bands. Instead, amateurs communicate with other radio amateurs individually by voice, digital or Morse code.

Sometimes radio amateurs participate in “networks” where groups meet frequently to share ideas. The grid operator switches the frequency one at a time for the rest of the group to hear.

In broadcasting, almost anyone can buy a station, a building permit, or a license. It just takes money. Amateur radio is different. For a fee of around $ 35, a person can take an exam to prove their knowledge of electronics and FCC rules. With a passing grade, the FCC will issue a license to that person, valid for 10 years with a cost of just $ 35 to renew. Try it out in broadcast!

Amateur radio currently has three license levels: Technician, General and Extra. Climbing that ladder with reviews gives hams more privileges and operating frequencies. Thousands of people have done it and so have you, especially now that fluency in Morse code is no longer required.

Call signs
Amateur radio operators and broadcasters receive call signs from the FCC.

Each call is unique and recognized around the world. There is only one WGN in Chicago, one W0HA for my wife Paula and only one W0MH for me. The (0) is zero, not O.

Call signs in other parts of our country use the numbers 1 to 9 separating the prefix from the suffix. They start with a G in England, XE in Mexico – the list extends to over 300 countries.

Because there are so many hams these days, the new US call signs look like KF2XYZ. To be clear, broadcast stations have call signs, but broadcast owners do not. An amateur call sign is assigned to an individual person.

Hams use their call signs to identify themselves every 10 minutes and at the end of a conversation. As you know, broadcasting stations are required to identify themselves once per hour. A broadcast ID has a call sign and a city. Hams only use their call sign. They can be mobile, on the water or even airborne.

SBE
The Society of Broadcast Engineers hosts a “Chapter of the Air” meeting on amateur radio on the second Sunday of each month on a single sideband of 14.205 MHz. Network control is Hal Hostetler, WA7BGX in Tucson, Arizona. It starts at 24:00 GMT. That is, 6 p.m. Central Minnesota Time in winter and 7 p.m. in summer. Hams record and tell about what happened in their life, like attending a NAB convention or SBE meeting. This group has participants from coast to coast.

Walrus
Upon entering the engineering room of a station, I heard Morse code letter B (Dah-Dit-Dit-Dit.)

amateur radio
Some hams prefer to communicate by Morse code.

It didn’t take long to realize that the sound was coming from a Best brand Ferrups uninterruptible power supply. The “B” told me his battery needed to be replaced. The letter H is a high temperature alarm. Very smart of them. Knowing Morse code is also useful on 450 MHz transmitter / studio links with Morse IDs. For those with Morse code issues, a phone call to a local hobbyist might reveal the answer when the sound is played on a phone.

Another way to speak English is Morse code. It’s not that hard to learn. If I can copy code with severe hearing loss, so can you. (I was a sergeant in the US Army in Vietnam from 1968 to 1969.) My wife Paula passed a 20 wpm code exam to earn her Amateur Extra Class license.

As mentioned, the code is not needed these days. Many hams find this to be a preferred mode of operation because it cuts noise so well. Many hams refer to Morse code as the original digital mode of communication.

The ham hobby
Some radio amateurs like to design and build equipment. Many like to work on antennas. Most like to chat with friends on the radio. Some continue DX (long distance contacts) to stations in foreign countries. They proudly stick a pin in a world map at every remote location.

Astronauts are licensed amateur radio operators. It’s a real pleasure to talk to a ham aboard the International Space Station. This can be done with just a few watts of power on VHF or UHF. The old adage is true: if you can see it, you can talk to it.

Conclusion
Broadcast engineers who are licensed amateur operators have a better grasp of the world of electronics. Getting an amateur license is another way to show their peers that they know something about RF. It’s another feather in their hat.

For more information on amateur radio, visit the ARRL, the National Association for Amateur Radio at www.arrl.org.

And learn more in this video on youtube.com: “W1AW ARRL Station Tour”.

Mark Persons, WØMH, CPBE, retired after 44 years, but continues to mentor broadcast engineers. For more articles and author resources, visit http://mwpersons.com.

Comment on this or any other article. Write to [email protected].


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